---
 freebsd/sys/kern/tty.c         | 2299 ++++++++++++++++++++++++++++++++++++++++
 freebsd/sys/kern/tty_inq.c     |  491 +++++++++
 freebsd/sys/kern/tty_outq.c    |  341 ++++++
 freebsd/sys/kern/tty_ttydisc.c | 1267 ++++++++++++++++++++++
 freebsd/sys/sys/_termios.h     |  222 ++++
 freebsd/sys/sys/cons.h         |  144 +++
 freebsd/sys/sys/serial.h       |   92 ++
 freebsd/sys/sys/timepps.h      |  266 +++++
 freebsd/sys/sys/ttydefaults.h  |  111 ++
 9 files changed, 5233 insertions(+)
 create mode 100644 freebsd/sys/kern/tty.c
 create mode 100644 freebsd/sys/kern/tty_inq.c
 create mode 100644 freebsd/sys/kern/tty_outq.c
 create mode 100644 freebsd/sys/kern/tty_ttydisc.c
 create mode 100644 freebsd/sys/sys/_termios.h
 create mode 100644 freebsd/sys/sys/cons.h
 create mode 100644 freebsd/sys/sys/serial.h
 create mode 100644 freebsd/sys/sys/timepps.h
 create mode 100644 freebsd/sys/sys/ttydefaults.h

diff --git a/freebsd/sys/kern/tty.c b/freebsd/sys/kern/tty.c
new file mode 100644
index 0000000..47932ee
--- /dev/null
+++ b/freebsd/sys/kern/tty.c
@@ -0,0 +1,2299 @@
+#include <machine/rtems-bsd-kernel-space.h>
+
+/*-
+ * Copyright (c) 2008 Ed Schouten <e...@freebsd.org>
+ * All rights reserved.
+ *
+ * Portions of this software were developed under sponsorship from Snow
+ * B.V., the Netherlands.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/local/opt_capsicum.h>
+#include <rtems/bsd/local/opt_compat.h>
+
+#include <rtems/bsd/sys/param.h>
+#include <sys/capsicum.h>
+#include <sys/conf.h>
+#include <sys/cons.h>
+#include <sys/fcntl.h>
+#include <sys/file.h>
+#include <sys/filedesc.h>
+#include <sys/filio.h>
+#ifdef COMPAT_43TTY
+#include <sys/ioctl_compat.h>
+#endif /* COMPAT_43TTY */
+#include <sys/kernel.h>
+#include <sys/limits.h>
+#include <sys/malloc.h>
+#include <sys/mount.h>
+#include <sys/poll.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/serial.h>
+#include <sys/signal.h>
+#include <sys/stat.h>
+#include <sys/sx.h>
+#include <sys/sysctl.h>
+#include <sys/systm.h>
+#include <sys/tty.h>
+#include <sys/ttycom.h>
+#define TTYDEFCHARS
+#include <sys/ttydefaults.h>
+#undef TTYDEFCHARS
+#include <sys/ucred.h>
+#include <sys/vnode.h>
+
+#include <machine/stdarg.h>
+
+static MALLOC_DEFINE(M_TTY, "tty", "tty device");
+
+static void tty_rel_free(struct tty *tp);
+
+static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
+static struct sx tty_list_sx;
+SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
+static unsigned int tty_list_count = 0;
+
+/* Character device of /dev/console. */
+static struct cdev     *dev_console;
+static const char      *dev_console_filename;
+
+/*
+ * Flags that are supported and stored by this implementation.
+ */
+#define TTYSUP_IFLAG   (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
+                       INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
+#define TTYSUP_OFLAG   (OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
+#define TTYSUP_LFLAG   (ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
+                       ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
+                       FLUSHO|NOKERNINFO|NOFLSH)
+#define TTYSUP_CFLAG   (CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
+                       HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
+                       CDSR_OFLOW|CCAR_OFLOW)
+
+#define        TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
+
+/*
+ * Set TTY buffer sizes.
+ */
+
+#define        TTYBUF_MAX      65536
+
+static void
+tty_watermarks(struct tty *tp)
+{
+       size_t bs = 0;
+
+       /* Provide an input buffer for 0.2 seconds of data. */
+       if (tp->t_termios.c_cflag & CREAD)
+               bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
+       ttyinq_setsize(&tp->t_inq, tp, bs);
+
+       /* Set low watermark at 10% (when 90% is available). */
+       tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
+
+       /* Provide an output buffer for 0.2 seconds of data. */
+       bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
+       ttyoutq_setsize(&tp->t_outq, tp, bs);
+
+       /* Set low watermark at 10% (when 90% is available). */
+       tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
+}
+
+static int
+tty_drain(struct tty *tp, int leaving)
+{
+       size_t bytesused;
+       int error;
+
+       if (ttyhook_hashook(tp, getc_inject))
+               /* buffer is inaccessible */
+               return (0);
+
+       while (ttyoutq_bytesused(&tp->t_outq) > 0 || ttydevsw_busy(tp)) {
+               ttydevsw_outwakeup(tp);
+               /* Could be handled synchronously. */
+               bytesused = ttyoutq_bytesused(&tp->t_outq);
+               if (bytesused == 0 && !ttydevsw_busy(tp))
+                       return (0);
+
+               /* Wait for data to be drained. */
+               if (leaving) {
+                       error = tty_timedwait(tp, &tp->t_outwait, hz);
+                       if (error == EWOULDBLOCK &&
+                           ttyoutq_bytesused(&tp->t_outq) < bytesused)
+                               error = 0;
+               } else
+                       error = tty_wait(tp, &tp->t_outwait);
+
+               if (error)
+                       return (error);
+       }
+
+       return (0);
+}
+
+/*
+ * Though ttydev_enter() and ttydev_leave() seem to be related, they
+ * don't have to be used together. ttydev_enter() is used by the cdev
+ * operations to prevent an actual operation from being processed when
+ * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
+ * and ttydev_close() to determine whether per-TTY data should be
+ * deallocated.
+ */
+
+static __inline int
+ttydev_enter(struct tty *tp)
+{
+
+       tty_lock(tp);
+
+       if (tty_gone(tp) || !tty_opened(tp)) {
+               /* Device is already gone. */
+               tty_unlock(tp);
+               return (ENXIO);
+       }
+
+       return (0);
+}
+
+static void
+ttydev_leave(struct tty *tp)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
+               /* Device is still opened somewhere. */
+               tty_unlock(tp);
+               return;
+       }
+
+       tp->t_flags |= TF_OPENCLOSE;
+
+       /* Stop asynchronous I/O. */
+       funsetown(&tp->t_sigio);
+
+       /* Remove console TTY. */
+       if (constty == tp)
+               constty_clear();
+
+       /* Drain any output. */
+       if (!tty_gone(tp))
+               tty_drain(tp, 1);
+
+       ttydisc_close(tp);
+
+       /* Free i/o queues now since they might be large. */
+       ttyinq_free(&tp->t_inq);
+       tp->t_inlow = 0;
+       ttyoutq_free(&tp->t_outq);
+       tp->t_outlow = 0;
+
+       knlist_clear(&tp->t_inpoll.si_note, 1);
+       knlist_clear(&tp->t_outpoll.si_note, 1);
+
+       if (!tty_gone(tp))
+               ttydevsw_close(tp);
+
+       tp->t_flags &= ~TF_OPENCLOSE;
+       cv_broadcast(&tp->t_dcdwait);
+       tty_rel_free(tp);
+}
+
+/*
+ * Operations that are exposed through the character device in /dev.
+ */
+static int
+ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
+    struct thread *td)
+{
+       struct tty *tp;
+       int error;
+
+       tp = dev->si_drv1;
+       error = 0;
+       tty_lock(tp);
+       if (tty_gone(tp)) {
+               /* Device is already gone. */
+               tty_unlock(tp);
+               return (ENXIO);
+       }
+
+       /*
+        * Block when other processes are currently opening or closing
+        * the TTY.
+        */
+       while (tp->t_flags & TF_OPENCLOSE) {
+               error = tty_wait(tp, &tp->t_dcdwait);
+               if (error != 0) {
+                       tty_unlock(tp);
+                       return (error);
+               }
+       }
+       tp->t_flags |= TF_OPENCLOSE;
+
+       /*
+        * Make sure the "tty" and "cua" device cannot be opened at the
+        * same time.  The console is a "tty" device.
+        */
+       if (TTY_CALLOUT(tp, dev)) {
+               if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
+                       error = EBUSY;
+                       goto done;
+               }
+       } else {
+               if (tp->t_flags & TF_OPENED_OUT) {
+                       error = EBUSY;
+                       goto done;
+               }
+       }
+
+       if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
+               error = EBUSY;
+               goto done;
+       }
+
+       if (!tty_opened(tp)) {
+               /* Set proper termios flags. */
+               if (TTY_CALLOUT(tp, dev))
+                       tp->t_termios = tp->t_termios_init_out;
+               else
+                       tp->t_termios = tp->t_termios_init_in;
+               ttydevsw_param(tp, &tp->t_termios);
+               /* Prevent modem control on callout devices and /dev/console. */
+               if (TTY_CALLOUT(tp, dev) || dev == dev_console)
+                       tp->t_termios.c_cflag |= CLOCAL;
+
+               ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
+
+               error = ttydevsw_open(tp);
+               if (error != 0)
+                       goto done;
+
+               ttydisc_open(tp);
+               tty_watermarks(tp); /* XXXGL: drops lock */
+       }
+
+       /* Wait for Carrier Detect. */
+       if ((oflags & O_NONBLOCK) == 0 &&
+           (tp->t_termios.c_cflag & CLOCAL) == 0) {
+               while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
+                       error = tty_wait(tp, &tp->t_dcdwait);
+                       if (error != 0)
+                               goto done;
+               }
+       }
+
+       if (dev == dev_console)
+               tp->t_flags |= TF_OPENED_CONS;
+       else if (TTY_CALLOUT(tp, dev))
+               tp->t_flags |= TF_OPENED_OUT;
+       else
+               tp->t_flags |= TF_OPENED_IN;
+       MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
+           (tp->t_flags & TF_OPENED_OUT) == 0);
+
+done:  tp->t_flags &= ~TF_OPENCLOSE;
+       cv_broadcast(&tp->t_dcdwait);
+       ttydev_leave(tp);
+
+       return (error);
+}
+
+static int
+ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
+    struct thread *td __unused)
+{
+       struct tty *tp = dev->si_drv1;
+
+       tty_lock(tp);
+
+       /*
+        * Don't actually close the device if it is being used as the
+        * console.
+        */
+       MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
+           (tp->t_flags & TF_OPENED_OUT) == 0);
+       if (dev == dev_console)
+               tp->t_flags &= ~TF_OPENED_CONS;
+       else
+               tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
+
+       if (tp->t_flags & TF_OPENED) {
+               tty_unlock(tp);
+               return (0);
+       }
+
+       /* If revoking, flush output now to avoid draining it later. */
+       if (fflag & FREVOKE)
+               tty_flush(tp, FWRITE);
+
+       tp->t_flags &= ~TF_EXCLUDE;
+
+       /* Properly wake up threads that are stuck - revoke(). */
+       tp->t_revokecnt++;
+       tty_wakeup(tp, FREAD|FWRITE);
+       cv_broadcast(&tp->t_bgwait);
+       cv_broadcast(&tp->t_dcdwait);
+
+       ttydev_leave(tp);
+
+       return (0);
+}
+
+static __inline int
+tty_is_ctty(struct tty *tp, struct proc *p)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
+}
+
+int
+tty_wait_background(struct tty *tp, struct thread *td, int sig)
+{
+       struct proc *p = td->td_proc;
+       struct pgrp *pg;
+       ksiginfo_t ksi;
+       int error;
+
+       MPASS(sig == SIGTTIN || sig == SIGTTOU);
+       tty_lock_assert(tp, MA_OWNED);
+
+       for (;;) {
+               PROC_LOCK(p);
+               /*
+                * The process should only sleep, when:
+                * - This terminal is the controlling terminal
+                * - Its process group is not the foreground process
+                *   group
+                * - The parent process isn't waiting for the child to
+                *   exit
+                * - the signal to send to the process isn't masked
+                */
+               if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
+                       /* Allow the action to happen. */
+                       PROC_UNLOCK(p);
+                       return (0);
+               }
+
+               if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
+                   SIGISMEMBER(td->td_sigmask, sig)) {
+                       /* Only allow them in write()/ioctl(). */
+                       PROC_UNLOCK(p);
+                       return (sig == SIGTTOU ? 0 : EIO);
+               }
+
+               pg = p->p_pgrp;
+               if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
+                       /* Don't allow the action to happen. */
+                       PROC_UNLOCK(p);
+                       return (EIO);
+               }
+               PROC_UNLOCK(p);
+
+               /*
+                * Send the signal and sleep until we're the new
+                * foreground process group.
+                */
+               if (sig != 0) {
+                       ksiginfo_init(&ksi);
+                       ksi.ksi_code = SI_KERNEL;
+                       ksi.ksi_signo = sig;
+                       sig = 0;
+               }
+               PGRP_LOCK(pg);
+               pgsignal(pg, ksi.ksi_signo, 1, &ksi);
+               PGRP_UNLOCK(pg);
+
+               error = tty_wait(tp, &tp->t_bgwait);
+               if (error)
+                       return (error);
+       }
+}
+
+static int
+ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
+{
+       struct tty *tp = dev->si_drv1;
+       int error;
+
+       error = ttydev_enter(tp);
+       if (error)
+               goto done;
+       error = ttydisc_read(tp, uio, ioflag);
+       tty_unlock(tp);
+
+       /*
+        * The read() call should not throw an error when the device is
+        * being destroyed. Silently convert it to an EOF.
+        */
+done:  if (error == ENXIO)
+               error = 0;
+       return (error);
+}
+
+static int
+ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
+{
+       struct tty *tp = dev->si_drv1;
+       int error;
+
+       error = ttydev_enter(tp);
+       if (error)
+               return (error);
+
+       if (tp->t_termios.c_lflag & TOSTOP) {
+               error = tty_wait_background(tp, curthread, SIGTTOU);
+               if (error)
+                       goto done;
+       }
+
+       if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
+               /* Allow non-blocking writes to bypass serialization. */
+               error = ttydisc_write(tp, uio, ioflag);
+       } else {
+               /* Serialize write() calls. */
+               while (tp->t_flags & TF_BUSY_OUT) {
+                       error = tty_wait(tp, &tp->t_outserwait);
+                       if (error)
+                               goto done;
+               }
+
+               tp->t_flags |= TF_BUSY_OUT;
+               error = ttydisc_write(tp, uio, ioflag);
+               tp->t_flags &= ~TF_BUSY_OUT;
+               cv_signal(&tp->t_outserwait);
+       }
+
+done:  tty_unlock(tp);
+       return (error);
+}
+
+static int
+ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
+    struct thread *td)
+{
+       struct tty *tp = dev->si_drv1;
+       int error;
+
+       error = ttydev_enter(tp);
+       if (error)
+               return (error);
+
+       switch (cmd) {
+       case TIOCCBRK:
+       case TIOCCONS:
+       case TIOCDRAIN:
+       case TIOCEXCL:
+       case TIOCFLUSH:
+       case TIOCNXCL:
+       case TIOCSBRK:
+       case TIOCSCTTY:
+       case TIOCSETA:
+       case TIOCSETAF:
+       case TIOCSETAW:
+       case TIOCSPGRP:
+       case TIOCSTART:
+       case TIOCSTAT:
+       case TIOCSTI:
+       case TIOCSTOP:
+       case TIOCSWINSZ:
+#if 0
+       case TIOCSDRAINWAIT:
+       case TIOCSETD:
+#endif
+#ifdef COMPAT_43TTY
+       case  TIOCLBIC:
+       case  TIOCLBIS:
+       case  TIOCLSET:
+       case  TIOCSETC:
+       case OTIOCSETD:
+       case  TIOCSETN:
+       case  TIOCSETP:
+       case  TIOCSLTC:
+#endif /* COMPAT_43TTY */
+               /*
+                * If the ioctl() causes the TTY to be modified, let it
+                * wait in the background.
+                */
+               error = tty_wait_background(tp, curthread, SIGTTOU);
+               if (error)
+                       goto done;
+       }
+
+       if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
+               struct termios *old = &tp->t_termios;
+               struct termios *new = (struct termios *)data;
+               struct termios *lock = TTY_CALLOUT(tp, dev) ?
+                   &tp->t_termios_lock_out : &tp->t_termios_lock_in;
+               int cc;
+
+               /*
+                * Lock state devices.  Just overwrite the values of the
+                * commands that are currently in use.
+                */
+               new->c_iflag = (old->c_iflag & lock->c_iflag) |
+                   (new->c_iflag & ~lock->c_iflag);
+               new->c_oflag = (old->c_oflag & lock->c_oflag) |
+                   (new->c_oflag & ~lock->c_oflag);
+               new->c_cflag = (old->c_cflag & lock->c_cflag) |
+                   (new->c_cflag & ~lock->c_cflag);
+               new->c_lflag = (old->c_lflag & lock->c_lflag) |
+                   (new->c_lflag & ~lock->c_lflag);
+               for (cc = 0; cc < NCCS; ++cc)
+                       if (lock->c_cc[cc])
+                               new->c_cc[cc] = old->c_cc[cc];
+               if (lock->c_ispeed)
+                       new->c_ispeed = old->c_ispeed;
+               if (lock->c_ospeed)
+                       new->c_ospeed = old->c_ospeed;
+       }
+
+       error = tty_ioctl(tp, cmd, data, fflag, td);
+done:  tty_unlock(tp);
+
+       return (error);
+}
+
+static int
+ttydev_poll(struct cdev *dev, int events, struct thread *td)
+{
+       struct tty *tp = dev->si_drv1;
+       int error, revents = 0;
+
+       error = ttydev_enter(tp);
+       if (error)
+               return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
+
+       if (events & (POLLIN|POLLRDNORM)) {
+               /* See if we can read something. */
+               if (ttydisc_read_poll(tp) > 0)
+                       revents |= events & (POLLIN|POLLRDNORM);
+       }
+
+       if (tp->t_flags & TF_ZOMBIE) {
+               /* Hangup flag on zombie state. */
+               revents |= POLLHUP;
+       } else if (events & (POLLOUT|POLLWRNORM)) {
+               /* See if we can write something. */
+               if (ttydisc_write_poll(tp) > 0)
+                       revents |= events & (POLLOUT|POLLWRNORM);
+       }
+
+       if (revents == 0) {
+               if (events & (POLLIN|POLLRDNORM))
+                       selrecord(td, &tp->t_inpoll);
+               if (events & (POLLOUT|POLLWRNORM))
+                       selrecord(td, &tp->t_outpoll);
+       }
+
+       tty_unlock(tp);
+
+       return (revents);
+}
+
+static int
+ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
+    int nprot, vm_memattr_t *memattr)
+{
+       struct tty *tp = dev->si_drv1;
+       int error;
+
+       /* Handle mmap() through the driver. */
+
+       error = ttydev_enter(tp);
+       if (error)
+               return (-1);
+       error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
+       tty_unlock(tp);
+
+       return (error);
+}
+
+/*
+ * kqueue support.
+ */
+
+static void
+tty_kqops_read_detach(struct knote *kn)
+{
+       struct tty *tp = kn->kn_hook;
+
+       knlist_remove(&tp->t_inpoll.si_note, kn, 0);
+}
+
+static int
+tty_kqops_read_event(struct knote *kn, long hint __unused)
+{
+       struct tty *tp = kn->kn_hook;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
+               kn->kn_flags |= EV_EOF;
+               return (1);
+       } else {
+               kn->kn_data = ttydisc_read_poll(tp);
+               return (kn->kn_data > 0);
+       }
+}
+
+static void
+tty_kqops_write_detach(struct knote *kn)
+{
+       struct tty *tp = kn->kn_hook;
+
+       knlist_remove(&tp->t_outpoll.si_note, kn, 0);
+}
+
+static int
+tty_kqops_write_event(struct knote *kn, long hint __unused)
+{
+       struct tty *tp = kn->kn_hook;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tty_gone(tp)) {
+               kn->kn_flags |= EV_EOF;
+               return (1);
+       } else {
+               kn->kn_data = ttydisc_write_poll(tp);
+               return (kn->kn_data > 0);
+       }
+}
+
+static struct filterops tty_kqops_read = {
+       .f_isfd = 1,
+       .f_detach = tty_kqops_read_detach,
+       .f_event = tty_kqops_read_event,
+};
+
+static struct filterops tty_kqops_write = {
+       .f_isfd = 1,
+       .f_detach = tty_kqops_write_detach,
+       .f_event = tty_kqops_write_event,
+};
+
+static int
+ttydev_kqfilter(struct cdev *dev, struct knote *kn)
+{
+       struct tty *tp = dev->si_drv1;
+       int error;
+
+       error = ttydev_enter(tp);
+       if (error)
+               return (error);
+
+       switch (kn->kn_filter) {
+       case EVFILT_READ:
+               kn->kn_hook = tp;
+               kn->kn_fop = &tty_kqops_read;
+               knlist_add(&tp->t_inpoll.si_note, kn, 1);
+               break;
+       case EVFILT_WRITE:
+               kn->kn_hook = tp;
+               kn->kn_fop = &tty_kqops_write;
+               knlist_add(&tp->t_outpoll.si_note, kn, 1);
+               break;
+       default:
+               error = EINVAL;
+               break;
+       }
+
+       tty_unlock(tp);
+       return (error);
+}
+
+static struct cdevsw ttydev_cdevsw = {
+       .d_version      = D_VERSION,
+       .d_open         = ttydev_open,
+       .d_close        = ttydev_close,
+       .d_read         = ttydev_read,
+       .d_write        = ttydev_write,
+       .d_ioctl        = ttydev_ioctl,
+       .d_kqfilter     = ttydev_kqfilter,
+       .d_poll         = ttydev_poll,
+       .d_mmap         = ttydev_mmap,
+       .d_name         = "ttydev",
+       .d_flags        = D_TTY,
+};
+
+/*
+ * Init/lock-state devices
+ */
+
+static int
+ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
+    struct thread *td)
+{
+       struct tty *tp;
+       int error;
+
+       tp = dev->si_drv1;
+       error = 0;
+       tty_lock(tp);
+       if (tty_gone(tp))
+               error = ENODEV;
+       tty_unlock(tp);
+
+       return (error);
+}
+
+static int
+ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
+    struct thread *td __unused)
+{
+
+       return (0);
+}
+
+static int
+ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
+    int ioflag __unused)
+{
+
+       return (ENODEV);
+}
+
+static int
+ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
+    struct thread *td)
+{
+       struct tty *tp = dev->si_drv1;
+       int error;
+
+       tty_lock(tp);
+       if (tty_gone(tp)) {
+               error = ENODEV;
+               goto done;
+       }
+
+       error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
+       if (error != ENOIOCTL)
+               goto done;
+       error = 0;
+
+       switch (cmd) {
+       case TIOCGETA:
+               /* Obtain terminal flags through tcgetattr(). */
+               *(struct termios*)data = *(struct termios*)dev->si_drv2;
+               break;
+       case TIOCSETA:
+               /* Set terminal flags through tcsetattr(). */
+               error = priv_check(td, PRIV_TTY_SETA);
+               if (error)
+                       break;
+               *(struct termios*)dev->si_drv2 = *(struct termios*)data;
+               break;
+       case TIOCGETD:
+               *(int *)data = TTYDISC;
+               break;
+       case TIOCGWINSZ:
+               bzero(data, sizeof(struct winsize));
+               break;
+       default:
+               error = ENOTTY;
+       }
+
+done:  tty_unlock(tp);
+       return (error);
+}
+
+static struct cdevsw ttyil_cdevsw = {
+       .d_version      = D_VERSION,
+       .d_open         = ttyil_open,
+       .d_close        = ttyil_close,
+       .d_read         = ttyil_rdwr,
+       .d_write        = ttyil_rdwr,
+       .d_ioctl        = ttyil_ioctl,
+       .d_name         = "ttyil",
+       .d_flags        = D_TTY,
+};
+
+static void
+tty_init_termios(struct tty *tp)
+{
+       struct termios *t = &tp->t_termios_init_in;
+
+       t->c_cflag = TTYDEF_CFLAG;
+       t->c_iflag = TTYDEF_IFLAG;
+       t->c_lflag = TTYDEF_LFLAG;
+       t->c_oflag = TTYDEF_OFLAG;
+       t->c_ispeed = TTYDEF_SPEED;
+       t->c_ospeed = TTYDEF_SPEED;
+       memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
+
+       tp->t_termios_init_out = *t;
+}
+
+void
+tty_init_console(struct tty *tp, speed_t s)
+{
+       struct termios *ti = &tp->t_termios_init_in;
+       struct termios *to = &tp->t_termios_init_out;
+
+       if (s != 0) {
+               ti->c_ispeed = ti->c_ospeed = s;
+               to->c_ispeed = to->c_ospeed = s;
+       }
+
+       ti->c_cflag |= CLOCAL;
+       to->c_cflag |= CLOCAL;
+}
+
+/*
+ * Standard device routine implementations, mostly meant for
+ * pseudo-terminal device drivers. When a driver creates a new terminal
+ * device class, missing routines are patched.
+ */
+
+static int
+ttydevsw_defopen(struct tty *tp __unused)
+{
+
+       return (0);
+}
+
+static void
+ttydevsw_defclose(struct tty *tp __unused)
+{
+
+}
+
+static void
+ttydevsw_defoutwakeup(struct tty *tp __unused)
+{
+
+       panic("Terminal device has output, while not implemented");
+}
+
+static void
+ttydevsw_definwakeup(struct tty *tp __unused)
+{
+
+}
+
+static int
+ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
+    caddr_t data __unused, struct thread *td __unused)
+{
+
+       return (ENOIOCTL);
+}
+
+static int
+ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
+    u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
+{
+
+       return (ENOIOCTL);
+}
+
+static int
+ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
+{
+
+       /*
+        * Allow the baud rate to be adjusted for pseudo-devices, but at
+        * least restrict it to 115200 to prevent excessive buffer
+        * usage.  Also disallow 0, to prevent foot shooting.
+        */
+       if (t->c_ispeed < B50)
+               t->c_ispeed = B50;
+       else if (t->c_ispeed > B115200)
+               t->c_ispeed = B115200;
+       if (t->c_ospeed < B50)
+               t->c_ospeed = B50;
+       else if (t->c_ospeed > B115200)
+               t->c_ospeed = B115200;
+       t->c_cflag |= CREAD;
+
+       return (0);
+}
+
+static int
+ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
+    int sigoff __unused)
+{
+
+       /* Simulate a carrier to make the TTY layer happy. */
+       return (SER_DCD);
+}
+
+static int
+ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
+    vm_paddr_t *paddr __unused, int nprot __unused,
+    vm_memattr_t *memattr __unused)
+{
+
+       return (-1);
+}
+
+static void
+ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
+{
+
+}
+
+static void
+ttydevsw_deffree(void *softc __unused)
+{
+
+       panic("Terminal device freed without a free-handler");
+}
+
+static bool
+ttydevsw_defbusy(struct tty *tp __unused)
+{
+
+       return (FALSE);
+}
+
+/*
+ * TTY allocation and deallocation. TTY devices can be deallocated when
+ * the driver doesn't use it anymore, when the TTY isn't a session's
+ * controlling TTY and when the device node isn't opened through devfs.
+ */
+
+struct tty *
+tty_alloc(struct ttydevsw *tsw, void *sc)
+{
+
+       return (tty_alloc_mutex(tsw, sc, NULL));
+}
+
+struct tty *
+tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
+{
+       struct tty *tp;
+
+       /* Make sure the driver defines all routines. */
+#define PATCH_FUNC(x) do {                             \
+       if (tsw->tsw_ ## x == NULL)                     \
+               tsw->tsw_ ## x = ttydevsw_def ## x;     \
+} while (0)
+       PATCH_FUNC(open);
+       PATCH_FUNC(close);
+       PATCH_FUNC(outwakeup);
+       PATCH_FUNC(inwakeup);
+       PATCH_FUNC(ioctl);
+       PATCH_FUNC(cioctl);
+       PATCH_FUNC(param);
+       PATCH_FUNC(modem);
+       PATCH_FUNC(mmap);
+       PATCH_FUNC(pktnotify);
+       PATCH_FUNC(free);
+       PATCH_FUNC(busy);
+#undef PATCH_FUNC
+
+       tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
+       tp->t_devsw = tsw;
+       tp->t_devswsoftc = sc;
+       tp->t_flags = tsw->tsw_flags;
+
+       tty_init_termios(tp);
+
+       cv_init(&tp->t_inwait, "ttyin");
+       cv_init(&tp->t_outwait, "ttyout");
+       cv_init(&tp->t_outserwait, "ttyosr");
+       cv_init(&tp->t_bgwait, "ttybg");
+       cv_init(&tp->t_dcdwait, "ttydcd");
+
+       /* Allow drivers to use a custom mutex to lock the TTY. */
+       if (mutex != NULL) {
+               tp->t_mtx = mutex;
+       } else {
+               tp->t_mtx = &tp->t_mtxobj;
+               mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
+       }
+
+       knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
+       knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
+
+       return (tp);
+}
+
+static void
+tty_dealloc(void *arg)
+{
+       struct tty *tp = arg;
+
+       /*
+        * ttyydev_leave() usually frees the i/o queues earlier, but it is
+        * not always called between queue allocation and here.  The queues
+        * may be allocated by ioctls on a pty control device without the
+        * corresponding pty slave device ever being open, or after it is
+        * closed.
+        */
+       ttyinq_free(&tp->t_inq);
+       ttyoutq_free(&tp->t_outq);
+       seldrain(&tp->t_inpoll);
+       seldrain(&tp->t_outpoll);
+       knlist_destroy(&tp->t_inpoll.si_note);
+       knlist_destroy(&tp->t_outpoll.si_note);
+
+       cv_destroy(&tp->t_inwait);
+       cv_destroy(&tp->t_outwait);
+       cv_destroy(&tp->t_bgwait);
+       cv_destroy(&tp->t_dcdwait);
+       cv_destroy(&tp->t_outserwait);
+
+       if (tp->t_mtx == &tp->t_mtxobj)
+               mtx_destroy(&tp->t_mtxobj);
+       ttydevsw_free(tp);
+       free(tp, M_TTY);
+}
+
+static void
+tty_rel_free(struct tty *tp)
+{
+       struct cdev *dev;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+#define        TF_ACTIVITY     (TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
+       if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
+               /* TTY is still in use. */
+               tty_unlock(tp);
+               return;
+       }
+
+       /* TTY can be deallocated. */
+       dev = tp->t_dev;
+       tp->t_dev = NULL;
+       tty_unlock(tp);
+
+       if (dev != NULL) {
+               sx_xlock(&tty_list_sx);
+               TAILQ_REMOVE(&tty_list, tp, t_list);
+               tty_list_count--;
+               sx_xunlock(&tty_list_sx);
+               destroy_dev_sched_cb(dev, tty_dealloc, tp);
+       }
+}
+
+void
+tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
+{
+
+       MPASS(tp->t_sessioncnt > 0);
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tp->t_pgrp == pg)
+               tp->t_pgrp = NULL;
+
+       tty_unlock(tp);
+}
+
+void
+tty_rel_sess(struct tty *tp, struct session *sess)
+{
+
+       MPASS(tp->t_sessioncnt > 0);
+
+       /* Current session has left. */
+       if (tp->t_session == sess) {
+               tp->t_session = NULL;
+               MPASS(tp->t_pgrp == NULL);
+       }
+       tp->t_sessioncnt--;
+       tty_rel_free(tp);
+}
+
+void
+tty_rel_gone(struct tty *tp)
+{
+
+       MPASS(!tty_gone(tp));
+
+       /* Simulate carrier removal. */
+       ttydisc_modem(tp, 0);
+
+       /* Wake up all blocked threads. */
+       tty_wakeup(tp, FREAD|FWRITE);
+       cv_broadcast(&tp->t_bgwait);
+       cv_broadcast(&tp->t_dcdwait);
+
+       tp->t_flags |= TF_GONE;
+       tty_rel_free(tp);
+}
+
+/*
+ * Exposing information about current TTY's through sysctl
+ */
+
+static void
+tty_to_xtty(struct tty *tp, struct xtty *xt)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       xt->xt_size = sizeof(struct xtty);
+       xt->xt_insize = ttyinq_getsize(&tp->t_inq);
+       xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
+       xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
+       xt->xt_inlow = tp->t_inlow;
+       xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
+       xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
+       xt->xt_outlow = tp->t_outlow;
+       xt->xt_column = tp->t_column;
+       xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
+       xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
+       xt->xt_flags = tp->t_flags;
+       xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
+}
+
+static int
+sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
+{
+       unsigned long lsize;
+       struct xtty *xtlist, *xt;
+       struct tty *tp;
+       int error;
+
+       sx_slock(&tty_list_sx);
+       lsize = tty_list_count * sizeof(struct xtty);
+       if (lsize == 0) {
+               sx_sunlock(&tty_list_sx);
+               return (0);
+       }
+
+       xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
+
+       TAILQ_FOREACH(tp, &tty_list, t_list) {
+               tty_lock(tp);
+               tty_to_xtty(tp, xt);
+               tty_unlock(tp);
+               xt++;
+       }
+       sx_sunlock(&tty_list_sx);
+
+       error = SYSCTL_OUT(req, xtlist, lsize);
+       free(xtlist, M_TTY);
+       return (error);
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
+       0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
+
+/*
+ * Device node creation. Device has been set up, now we can expose it to
+ * the user.
+ */
+
+int
+tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
+    const char *fmt, ...)
+{
+       va_list ap;
+       struct make_dev_args args;
+       struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
+       const char *prefix = "tty";
+       char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
+       uid_t uid;
+       gid_t gid;
+       mode_t mode;
+       int error;
+
+       /* Remove "tty" prefix from devices like PTY's. */
+       if (tp->t_flags & TF_NOPREFIX)
+               prefix = "";
+
+       va_start(ap, fmt);
+       vsnrprintf(name, sizeof name, 32, fmt, ap);
+       va_end(ap);
+
+       if (cred == NULL) {
+               /* System device. */
+               uid = UID_ROOT;
+               gid = GID_WHEEL;
+               mode = S_IRUSR|S_IWUSR;
+       } else {
+               /* User device. */
+               uid = cred->cr_ruid;
+               gid = GID_TTY;
+               mode = S_IRUSR|S_IWUSR|S_IWGRP;
+       }
+
+       flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
+       flags |= MAKEDEV_CHECKNAME;
+
+       /* Master call-in device. */
+       make_dev_args_init(&args);
+       args.mda_flags = flags;
+       args.mda_devsw = &ttydev_cdevsw;
+       args.mda_cr = cred;
+       args.mda_uid = uid;
+       args.mda_gid = gid;
+       args.mda_mode = mode;
+       args.mda_si_drv1 = tp;
+       error = make_dev_s(&args, &dev, "%s%s", prefix, name);
+       if (error != 0)
+               return (error);
+       tp->t_dev = dev;
+
+       init = lock = cua = cinit = clock = NULL;
+
+       /* Slave call-in devices. */
+       if (tp->t_flags & TF_INITLOCK) {
+               args.mda_devsw = &ttyil_cdevsw;
+               args.mda_unit = TTYUNIT_INIT;
+               args.mda_si_drv1 = tp;
+               args.mda_si_drv2 = &tp->t_termios_init_in;
+               error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
+               if (error != 0)
+                       goto fail;
+               dev_depends(dev, init);
+
+               args.mda_unit = TTYUNIT_LOCK;
+               args.mda_si_drv2 = &tp->t_termios_lock_in;
+               error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
+               if (error != 0)
+                       goto fail;
+               dev_depends(dev, lock);
+       }
+
+       /* Call-out devices. */
+       if (tp->t_flags & TF_CALLOUT) {
+               make_dev_args_init(&args);
+               args.mda_flags = flags;
+               args.mda_devsw = &ttydev_cdevsw;
+               args.mda_cr = cred;
+               args.mda_uid = UID_UUCP;
+               args.mda_gid = GID_DIALER;
+               args.mda_mode = 0660;
+               args.mda_unit = TTYUNIT_CALLOUT;
+               args.mda_si_drv1 = tp;
+               error = make_dev_s(&args, &cua, "cua%s", name);
+               if (error != 0)
+                       goto fail;
+               dev_depends(dev, cua);
+
+               /* Slave call-out devices. */
+               if (tp->t_flags & TF_INITLOCK) {
+                       args.mda_devsw = &ttyil_cdevsw;
+                       args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
+                       args.mda_si_drv2 = &tp->t_termios_init_out;
+                       error = make_dev_s(&args, &cinit, "cua%s.init", name);
+                       if (error != 0)
+                               goto fail;
+                       dev_depends(dev, cinit);
+
+                       args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
+                       args.mda_si_drv2 = &tp->t_termios_lock_out;
+                       error = make_dev_s(&args, &clock, "cua%s.lock", name);
+                       if (error != 0)
+                               goto fail;
+                       dev_depends(dev, clock);
+               }
+       }
+
+       sx_xlock(&tty_list_sx);
+       TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
+       tty_list_count++;
+       sx_xunlock(&tty_list_sx);
+
+       return (0);
+
+fail:
+       destroy_dev(dev);
+       if (init)
+               destroy_dev(init);
+       if (lock)
+               destroy_dev(lock);
+       if (cinit)
+               destroy_dev(cinit);
+       if (clock)
+               destroy_dev(clock);
+
+       return (error);
+}
+
+/*
+ * Signalling processes.
+ */
+
+void
+tty_signal_sessleader(struct tty *tp, int sig)
+{
+       struct proc *p;
+
+       tty_lock_assert(tp, MA_OWNED);
+       MPASS(sig >= 1 && sig < NSIG);
+
+       /* Make signals start output again. */
+       tp->t_flags &= ~TF_STOPPED;
+
+       if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
+               p = tp->t_session->s_leader;
+               PROC_LOCK(p);
+               kern_psignal(p, sig);
+               PROC_UNLOCK(p);
+       }
+}
+
+void
+tty_signal_pgrp(struct tty *tp, int sig)
+{
+       ksiginfo_t ksi;
+
+       tty_lock_assert(tp, MA_OWNED);
+       MPASS(sig >= 1 && sig < NSIG);
+
+       /* Make signals start output again. */
+       tp->t_flags &= ~TF_STOPPED;
+
+       if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
+               tty_info(tp);
+       if (tp->t_pgrp != NULL) {
+               ksiginfo_init(&ksi);
+               ksi.ksi_signo = sig;
+               ksi.ksi_code = SI_KERNEL;
+               PGRP_LOCK(tp->t_pgrp);
+               pgsignal(tp->t_pgrp, sig, 1, &ksi);
+               PGRP_UNLOCK(tp->t_pgrp);
+       }
+}
+
+void
+tty_wakeup(struct tty *tp, int flags)
+{
+
+       if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
+               pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
+
+       if (flags & FWRITE) {
+               cv_broadcast(&tp->t_outwait);
+               selwakeup(&tp->t_outpoll);
+               KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
+       }
+       if (flags & FREAD) {
+               cv_broadcast(&tp->t_inwait);
+               selwakeup(&tp->t_inpoll);
+               KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
+       }
+}
+
+int
+tty_wait(struct tty *tp, struct cv *cv)
+{
+       int error;
+       int revokecnt = tp->t_revokecnt;
+
+       tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
+       MPASS(!tty_gone(tp));
+
+       error = cv_wait_sig(cv, tp->t_mtx);
+
+       /* Bail out when the device slipped away. */
+       if (tty_gone(tp))
+               return (ENXIO);
+
+       /* Restart the system call when we may have been revoked. */
+       if (tp->t_revokecnt != revokecnt)
+               return (ERESTART);
+
+       return (error);
+}
+
+int
+tty_timedwait(struct tty *tp, struct cv *cv, int hz)
+{
+       int error;
+       int revokecnt = tp->t_revokecnt;
+
+       tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
+       MPASS(!tty_gone(tp));
+
+       error = cv_timedwait_sig(cv, tp->t_mtx, hz);
+
+       /* Bail out when the device slipped away. */
+       if (tty_gone(tp))
+               return (ENXIO);
+
+       /* Restart the system call when we may have been revoked. */
+       if (tp->t_revokecnt != revokecnt)
+               return (ERESTART);
+
+       return (error);
+}
+
+void
+tty_flush(struct tty *tp, int flags)
+{
+
+       if (flags & FWRITE) {
+               tp->t_flags &= ~TF_HIWAT_OUT;
+               ttyoutq_flush(&tp->t_outq);
+               tty_wakeup(tp, FWRITE);
+               if (!tty_gone(tp)) {
+                       ttydevsw_outwakeup(tp);
+                       ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
+               }
+       }
+       if (flags & FREAD) {
+               tty_hiwat_in_unblock(tp);
+               ttyinq_flush(&tp->t_inq);
+               tty_wakeup(tp, FREAD);
+               if (!tty_gone(tp)) {
+                       ttydevsw_inwakeup(tp);
+                       ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
+               }
+       }
+}
+
+void
+tty_set_winsize(struct tty *tp, const struct winsize *wsz)
+{
+
+       if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
+               return;
+       tp->t_winsize = *wsz;
+       tty_signal_pgrp(tp, SIGWINCH);
+}
+
+static int
+tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
+    struct thread *td)
+{
+       int error;
+
+       switch (cmd) {
+       /*
+        * Modem commands.
+        * The SER_* and TIOCM_* flags are the same, but one bit
+        * shifted. I don't know why.
+        */
+       case TIOCSDTR:
+               ttydevsw_modem(tp, SER_DTR, 0);
+               return (0);
+       case TIOCCDTR:
+               ttydevsw_modem(tp, 0, SER_DTR);
+               return (0);
+       case TIOCMSET: {
+               int bits = *(int *)data;
+               ttydevsw_modem(tp,
+                   (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
+                   ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
+               return (0);
+       }
+       case TIOCMBIS: {
+               int bits = *(int *)data;
+               ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
+               return (0);
+       }
+       case TIOCMBIC: {
+               int bits = *(int *)data;
+               ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
+               return (0);
+       }
+       case TIOCMGET:
+               *(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
+               return (0);
+
+       case FIOASYNC:
+               if (*(int *)data)
+                       tp->t_flags |= TF_ASYNC;
+               else
+                       tp->t_flags &= ~TF_ASYNC;
+               return (0);
+       case FIONBIO:
+               /* This device supports non-blocking operation. */
+               return (0);
+       case FIONREAD:
+               *(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
+               return (0);
+       case FIONWRITE:
+       case TIOCOUTQ:
+               *(int *)data = ttyoutq_bytesused(&tp->t_outq);
+               return (0);
+       case FIOSETOWN:
+               if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
+                       /* Not allowed to set ownership. */
+                       return (ENOTTY);
+
+               /* Temporarily unlock the TTY to set ownership. */
+               tty_unlock(tp);
+               error = fsetown(*(int *)data, &tp->t_sigio);
+               tty_lock(tp);
+               return (error);
+       case FIOGETOWN:
+               if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
+                       /* Not allowed to set ownership. */
+                       return (ENOTTY);
+
+               /* Get ownership. */
+               *(int *)data = fgetown(&tp->t_sigio);
+               return (0);
+       case TIOCGETA:
+               /* Obtain terminal flags through tcgetattr(). */
+               *(struct termios*)data = tp->t_termios;
+               return (0);
+       case TIOCSETA:
+       case TIOCSETAW:
+       case TIOCSETAF: {
+               struct termios *t = data;
+
+               /*
+                * Who makes up these funny rules? According to POSIX,
+                * input baud rate is set equal to the output baud rate
+                * when zero.
+                */
+               if (t->c_ispeed == 0)
+                       t->c_ispeed = t->c_ospeed;
+
+               /* Discard any unsupported bits. */
+               t->c_iflag &= TTYSUP_IFLAG;
+               t->c_oflag &= TTYSUP_OFLAG;
+               t->c_lflag &= TTYSUP_LFLAG;
+               t->c_cflag &= TTYSUP_CFLAG;
+
+               /* Set terminal flags through tcsetattr(). */
+               if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
+                       error = tty_drain(tp, 0);
+                       if (error)
+                               return (error);
+                       if (cmd == TIOCSETAF)
+                               tty_flush(tp, FREAD);
+               }
+
+               /*
+                * Only call param() when the flags really change.
+                */
+               if ((t->c_cflag & CIGNORE) == 0 &&
+                   (tp->t_termios.c_cflag != t->c_cflag ||
+                   ((tp->t_termios.c_iflag ^ t->c_iflag) &
+                   (IXON|IXOFF|IXANY)) ||
+                   tp->t_termios.c_ispeed != t->c_ispeed ||
+                   tp->t_termios.c_ospeed != t->c_ospeed)) {
+                       error = ttydevsw_param(tp, t);
+                       if (error)
+                               return (error);
+
+                       /* XXX: CLOCAL? */
+
+                       tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
+                       tp->t_termios.c_ispeed = t->c_ispeed;
+                       tp->t_termios.c_ospeed = t->c_ospeed;
+
+                       /* Baud rate has changed - update watermarks. */
+                       tty_watermarks(tp);
+               }
+
+               /* Copy new non-device driver parameters. */
+               tp->t_termios.c_iflag = t->c_iflag;
+               tp->t_termios.c_oflag = t->c_oflag;
+               tp->t_termios.c_lflag = t->c_lflag;
+               memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
+
+               ttydisc_optimize(tp);
+
+               if ((t->c_lflag & ICANON) == 0) {
+                       /*
+                        * When in non-canonical mode, wake up all
+                        * readers. Canonicalize any partial input. VMIN
+                        * and VTIME could also be adjusted.
+                        */
+                       ttyinq_canonicalize(&tp->t_inq);
+                       tty_wakeup(tp, FREAD);
+               }
+
+               /*
+                * For packet mode: notify the PTY consumer that VSTOP
+                * and VSTART may have been changed.
+                */
+               if (tp->t_termios.c_iflag & IXON &&
+                   tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
+                   tp->t_termios.c_cc[VSTART] == CTRL('Q'))
+                       ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
+               else
+                       ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
+               return (0);
+       }
+       case TIOCGETD:
+               /* For compatibility - we only support TTYDISC. */
+               *(int *)data = TTYDISC;
+               return (0);
+       case TIOCGPGRP:
+               if (!tty_is_ctty(tp, td->td_proc))
+                       return (ENOTTY);
+
+               if (tp->t_pgrp != NULL)
+                       *(int *)data = tp->t_pgrp->pg_id;
+               else
+                       *(int *)data = NO_PID;
+               return (0);
+       case TIOCGSID:
+               if (!tty_is_ctty(tp, td->td_proc))
+                       return (ENOTTY);
+
+               MPASS(tp->t_session);
+               *(int *)data = tp->t_session->s_sid;
+               return (0);
+       case TIOCSCTTY: {
+               struct proc *p = td->td_proc;
+
+               /* XXX: This looks awful. */
+               tty_unlock(tp);
+               sx_xlock(&proctree_lock);
+               tty_lock(tp);
+
+               if (!SESS_LEADER(p)) {
+                       /* Only the session leader may do this. */
+                       sx_xunlock(&proctree_lock);
+                       return (EPERM);
+               }
+
+               if (tp->t_session != NULL && tp->t_session == p->p_session) {
+                       /* This is already our controlling TTY. */
+                       sx_xunlock(&proctree_lock);
+                       return (0);
+               }
+
+               if (p->p_session->s_ttyp != NULL ||
+                   (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
+                   tp->t_session->s_ttyvp->v_type != VBAD)) {
+                       /*
+                        * There is already a relation between a TTY and
+                        * a session, or the caller is not the session
+                        * leader.
+                        *
+                        * Allow the TTY to be stolen when the vnode is
+                        * invalid, but the reference to the TTY is
+                        * still active.  This allows immediate reuse of
+                        * TTYs of which the session leader has been
+                        * killed or the TTY revoked.
+                        */
+                       sx_xunlock(&proctree_lock);
+                       return (EPERM);
+               }
+
+               /* Connect the session to the TTY. */
+               tp->t_session = p->p_session;
+               tp->t_session->s_ttyp = tp;
+               tp->t_sessioncnt++;
+               sx_xunlock(&proctree_lock);
+
+               /* Assign foreground process group. */
+               tp->t_pgrp = p->p_pgrp;
+               PROC_LOCK(p);
+               p->p_flag |= P_CONTROLT;
+               PROC_UNLOCK(p);
+
+               return (0);
+       }
+       case TIOCSPGRP: {
+               struct pgrp *pg;
+
+               /*
+                * XXX: Temporarily unlock the TTY to locate the process
+                * group. This code would be lot nicer if we would ever
+                * decompose proctree_lock.
+                */
+               tty_unlock(tp);
+               sx_slock(&proctree_lock);
+               pg = pgfind(*(int *)data);
+               if (pg != NULL)
+                       PGRP_UNLOCK(pg);
+               if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
+                       sx_sunlock(&proctree_lock);
+                       tty_lock(tp);
+                       return (EPERM);
+               }
+               tty_lock(tp);
+
+               /*
+                * Determine if this TTY is the controlling TTY after
+                * relocking the TTY.
+                */
+               if (!tty_is_ctty(tp, td->td_proc)) {
+                       sx_sunlock(&proctree_lock);
+                       return (ENOTTY);
+               }
+               tp->t_pgrp = pg;
+               sx_sunlock(&proctree_lock);
+
+               /* Wake up the background process groups. */
+               cv_broadcast(&tp->t_bgwait);
+               return (0);
+       }
+       case TIOCFLUSH: {
+               int flags = *(int *)data;
+
+               if (flags == 0)
+                       flags = (FREAD|FWRITE);
+               else
+                       flags &= (FREAD|FWRITE);
+               tty_flush(tp, flags);
+               return (0);
+       }
+       case TIOCDRAIN:
+               /* Drain TTY output. */
+               return tty_drain(tp, 0);
+       case TIOCCONS:
+               /* Set terminal as console TTY. */
+               if (*(int *)data) {
+                       error = priv_check(td, PRIV_TTY_CONSOLE);
+                       if (error)
+                               return (error);
+
+                       /*
+                        * XXX: constty should really need to be locked!
+                        * XXX: allow disconnected constty's to be stolen!
+                        */
+
+                       if (constty == tp)
+                               return (0);
+                       if (constty != NULL)
+                               return (EBUSY);
+
+                       tty_unlock(tp);
+                       constty_set(tp);
+                       tty_lock(tp);
+               } else if (constty == tp) {
+                       constty_clear();
+               }
+               return (0);
+       case TIOCGWINSZ:
+               /* Obtain window size. */
+               *(struct winsize*)data = tp->t_winsize;
+               return (0);
+       case TIOCSWINSZ:
+               /* Set window size. */
+               tty_set_winsize(tp, data);
+               return (0);
+       case TIOCEXCL:
+               tp->t_flags |= TF_EXCLUDE;
+               return (0);
+       case TIOCNXCL:
+               tp->t_flags &= ~TF_EXCLUDE;
+               return (0);
+       case TIOCSTOP:
+               tp->t_flags |= TF_STOPPED;
+               ttydevsw_pktnotify(tp, TIOCPKT_STOP);
+               return (0);
+       case TIOCSTART:
+               tp->t_flags &= ~TF_STOPPED;
+               ttydevsw_outwakeup(tp);
+               ttydevsw_pktnotify(tp, TIOCPKT_START);
+               return (0);
+       case TIOCSTAT:
+               tty_info(tp);
+               return (0);
+       case TIOCSTI:
+               if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
+                       return (EPERM);
+               if (!tty_is_ctty(tp, td->td_proc) &&
+                   priv_check(td, PRIV_TTY_STI))
+                       return (EACCES);
+               ttydisc_rint(tp, *(char *)data, 0);
+               ttydisc_rint_done(tp);
+               return (0);
+       }
+
+#ifdef COMPAT_43TTY
+       return tty_ioctl_compat(tp, cmd, data, fflag, td);
+#else /* !COMPAT_43TTY */
+       return (ENOIOCTL);
+#endif /* COMPAT_43TTY */
+}
+
+int
+tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
+{
+       int error;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tty_gone(tp))
+               return (ENXIO);
+
+       error = ttydevsw_ioctl(tp, cmd, data, td);
+       if (error == ENOIOCTL)
+               error = tty_generic_ioctl(tp, cmd, data, fflag, td);
+
+       return (error);
+}
+
+dev_t
+tty_udev(struct tty *tp)
+{
+
+       if (tp->t_dev)
+               return (dev2udev(tp->t_dev));
+       else
+               return (NODEV);
+}
+
+int
+tty_checkoutq(struct tty *tp)
+{
+
+       /* 256 bytes should be enough to print a log message. */
+       return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
+}
+
+void
+tty_hiwat_in_block(struct tty *tp)
+{
+
+       if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
+           tp->t_termios.c_iflag & IXOFF &&
+           tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
+               /*
+                * Input flow control. Only enter the high watermark when we
+                * can successfully store the VSTOP character.
+                */
+               if (ttyoutq_write_nofrag(&tp->t_outq,
+                   &tp->t_termios.c_cc[VSTOP], 1) == 0)
+                       tp->t_flags |= TF_HIWAT_IN;
+       } else {
+               /* No input flow control. */
+               tp->t_flags |= TF_HIWAT_IN;
+       }
+}
+
+void
+tty_hiwat_in_unblock(struct tty *tp)
+{
+
+       if (tp->t_flags & TF_HIWAT_IN &&
+           tp->t_termios.c_iflag & IXOFF &&
+           tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
+               /*
+                * Input flow control. Only leave the high watermark when we
+                * can successfully store the VSTART character.
+                */
+               if (ttyoutq_write_nofrag(&tp->t_outq,
+                   &tp->t_termios.c_cc[VSTART], 1) == 0)
+                       tp->t_flags &= ~TF_HIWAT_IN;
+       } else {
+               /* No input flow control. */
+               tp->t_flags &= ~TF_HIWAT_IN;
+       }
+
+       if (!tty_gone(tp))
+               ttydevsw_inwakeup(tp);
+}
+
+/*
+ * TTY hooks interface.
+ */
+
+static int
+ttyhook_defrint(struct tty *tp, char c, int flags)
+{
+
+       if (ttyhook_rint_bypass(tp, &c, 1) != 1)
+               return (-1);
+
+       return (0);
+}
+
+int
+ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
+    void *softc)
+{
+       struct tty *tp;
+       struct file *fp;
+       struct cdev *dev;
+       struct cdevsw *cdp;
+       struct filedesc *fdp;
+       cap_rights_t rights;
+       int error, ref;
+
+       /* Validate the file descriptor. */
+       fdp = p->p_fd;
+       error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
+           &fp, NULL);
+       if (error != 0)
+               return (error);
+       if (fp->f_ops == &badfileops) {
+               error = EBADF;
+               goto done1;
+       }
+
+       /*
+        * Make sure the vnode is bound to a character device.
+        * Unlocked check for the vnode type is ok there, because we
+        * only shall prevent calling devvn_refthread on the file that
+        * never has been opened over a character device.
+        */
+       if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
+               error = EINVAL;
+               goto done1;
+       }
+
+       /* Make sure it is a TTY. */
+       cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
+       if (cdp == NULL) {
+               error = ENXIO;
+               goto done1;
+       }
+       if (dev != fp->f_data) {
+               error = ENXIO;
+               goto done2;
+       }
+       if (cdp != &ttydev_cdevsw) {
+               error = ENOTTY;
+               goto done2;
+       }
+       tp = dev->si_drv1;
+
+       /* Try to attach the hook to the TTY. */
+       error = EBUSY;
+       tty_lock(tp);
+       MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
+       if (tp->t_flags & TF_HOOK)
+               goto done3;
+
+       tp->t_flags |= TF_HOOK;
+       tp->t_hook = th;
+       tp->t_hooksoftc = softc;
+       *rtp = tp;
+       error = 0;
+
+       /* Maybe we can switch into bypass mode now. */
+       ttydisc_optimize(tp);
+
+       /* Silently convert rint() calls to rint_bypass() when possible. */
+       if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
+               th->th_rint = ttyhook_defrint;
+
+done3: tty_unlock(tp);
+done2: dev_relthread(dev, ref);
+done1: fdrop(fp, curthread);
+       return (error);
+}
+
+void
+ttyhook_unregister(struct tty *tp)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+       MPASS(tp->t_flags & TF_HOOK);
+
+       /* Disconnect the hook. */
+       tp->t_flags &= ~TF_HOOK;
+       tp->t_hook = NULL;
+
+       /* Maybe we need to leave bypass mode. */
+       ttydisc_optimize(tp);
+
+       /* Maybe deallocate the TTY as well. */
+       tty_rel_free(tp);
+}
+
+/*
+ * /dev/console handling.
+ */
+
+static int
+ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
+{
+       struct tty *tp;
+
+       /* System has no console device. */
+       if (dev_console_filename == NULL)
+               return (ENXIO);
+
+       /* Look up corresponding TTY by device name. */
+       sx_slock(&tty_list_sx);
+       TAILQ_FOREACH(tp, &tty_list, t_list) {
+               if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
+                       dev_console->si_drv1 = tp;
+                       break;
+               }
+       }
+       sx_sunlock(&tty_list_sx);
+
+       /* System console has no TTY associated. */
+       if (dev_console->si_drv1 == NULL)
+               return (ENXIO);
+
+       return (ttydev_open(dev, oflags, devtype, td));
+}
+
+static int
+ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
+{
+
+       log_console(uio);
+
+       return (ttydev_write(dev, uio, ioflag));
+}
+
+/*
+ * /dev/console is a little different than normal TTY's.  When opened,
+ * it determines which TTY to use.  When data gets written to it, it
+ * will be logged in the kernel message buffer.
+ */
+static struct cdevsw ttyconsdev_cdevsw = {
+       .d_version      = D_VERSION,
+       .d_open         = ttyconsdev_open,
+       .d_close        = ttydev_close,
+       .d_read         = ttydev_read,
+       .d_write        = ttyconsdev_write,
+       .d_ioctl        = ttydev_ioctl,
+       .d_kqfilter     = ttydev_kqfilter,
+       .d_poll         = ttydev_poll,
+       .d_mmap         = ttydev_mmap,
+       .d_name         = "ttyconsdev",
+       .d_flags        = D_TTY,
+};
+
+static void
+ttyconsdev_init(void *unused __unused)
+{
+
+       dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
+           NULL, UID_ROOT, GID_WHEEL, 0600, "console");
+}
+
+SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
+
+void
+ttyconsdev_select(const char *name)
+{
+
+       dev_console_filename = name;
+}
+
+/*
+ * Debugging routines.
+ */
+
+#include <rtems/bsd/local/opt_ddb.h>
+#ifdef DDB
+#include <ddb/ddb.h>
+#include <ddb/db_sym.h>
+
+static const struct {
+       int flag;
+       char val;
+} ttystates[] = {
+#if 0
+       { TF_NOPREFIX,          'N' },
+#endif
+       { TF_INITLOCK,          'I' },
+       { TF_CALLOUT,           'C' },
+
+       /* Keep these together -> 'Oi' and 'Oo'. */
+       { TF_OPENED,            'O' },
+       { TF_OPENED_IN,         'i' },
+       { TF_OPENED_OUT,        'o' },
+       { TF_OPENED_CONS,       'c' },
+
+       { TF_GONE,              'G' },
+       { TF_OPENCLOSE,         'B' },
+       { TF_ASYNC,             'Y' },
+       { TF_LITERAL,           'L' },
+
+       /* Keep these together -> 'Hi' and 'Ho'. */
+       { TF_HIWAT,             'H' },
+       { TF_HIWAT_IN,          'i' },
+       { TF_HIWAT_OUT,         'o' },
+
+       { TF_STOPPED,           'S' },
+       { TF_EXCLUDE,           'X' },
+       { TF_BYPASS,            'l' },
+       { TF_ZOMBIE,            'Z' },
+       { TF_HOOK,              's' },
+
+       /* Keep these together -> 'bi' and 'bo'. */
+       { TF_BUSY,              'b' },
+       { TF_BUSY_IN,           'i' },
+       { TF_BUSY_OUT,          'o' },
+
+       { 0,                    '\0'},
+};
+
+#define        TTY_FLAG_BITS \
+       "\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
+       "\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
+       "\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
+       "\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
+       "\21HOOK\22BUSY_IN\23BUSY_OUT"
+
+#define DB_PRINTSYM(name, addr) \
+       db_printf("%s  " #name ": ", sep); \
+       db_printsym((db_addr_t) addr, DB_STGY_ANY); \
+       db_printf("\n");
+
+static void
+_db_show_devsw(const char *sep, const struct ttydevsw *tsw)
+{
+
+       db_printf("%sdevsw: ", sep);
+       db_printsym((db_addr_t)tsw, DB_STGY_ANY);
+       db_printf(" (%p)\n", tsw);
+       DB_PRINTSYM(open, tsw->tsw_open);
+       DB_PRINTSYM(close, tsw->tsw_close);
+       DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
+       DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
+       DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
+       DB_PRINTSYM(param, tsw->tsw_param);
+       DB_PRINTSYM(modem, tsw->tsw_modem);
+       DB_PRINTSYM(mmap, tsw->tsw_mmap);
+       DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
+       DB_PRINTSYM(free, tsw->tsw_free);
+}
+
+static void
+_db_show_hooks(const char *sep, const struct ttyhook *th)
+{
+
+       db_printf("%shook: ", sep);
+       db_printsym((db_addr_t)th, DB_STGY_ANY);
+       db_printf(" (%p)\n", th);
+       if (th == NULL)
+               return;
+       DB_PRINTSYM(rint, th->th_rint);
+       DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
+       DB_PRINTSYM(rint_done, th->th_rint_done);
+       DB_PRINTSYM(rint_poll, th->th_rint_poll);
+       DB_PRINTSYM(getc_inject, th->th_getc_inject);
+       DB_PRINTSYM(getc_capture, th->th_getc_capture);
+       DB_PRINTSYM(getc_poll, th->th_getc_poll);
+       DB_PRINTSYM(close, th->th_close);
+}
+
+static void
+_db_show_termios(const char *name, const struct termios *t)
+{
+
+       db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
+           "lflag 0x%x ispeed %u ospeed %u\n", name,
+           t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
+           t->c_ispeed, t->c_ospeed);
+}
+
+/* DDB command to show TTY statistics. */
+DB_SHOW_COMMAND(tty, db_show_tty)
+{
+       struct tty *tp;
+
+       if (!have_addr) {
+               db_printf("usage: show tty <addr>\n");
+               return;
+       }
+       tp = (struct tty *)addr;
+
+       db_printf("%p: %s\n", tp, tty_devname(tp));
+       db_printf("\tmtx: %p\n", tp->t_mtx);
+       db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
+       db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
+
+       /* Buffering mechanisms. */
+       db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
+           "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
+           tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
+           tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
+       db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
+           &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
+           tp->t_outq.to_nblocks, tp->t_outq.to_quota);
+       db_printf("\tinlow: %zu\n", tp->t_inlow);
+       db_printf("\toutlow: %zu\n", tp->t_outlow);
+       _db_show_termios("\ttermios", &tp->t_termios);
+       db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
+           tp->t_winsize.ws_row, tp->t_winsize.ws_col,
+           tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
+       db_printf("\tcolumn: %u\n", tp->t_column);
+       db_printf("\twritepos: %u\n", tp->t_writepos);
+       db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
+
+       /* Init/lock-state devices. */
+       _db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
+       _db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
+       _db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
+       _db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
+
+       /* Hooks */
+       _db_show_devsw("\t", tp->t_devsw);
+       _db_show_hooks("\t", tp->t_hook);
+
+       /* Process info. */
+       db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
+           tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
+           tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
+       db_printf("\tsession: %p", tp->t_session);
+       if (tp->t_session != NULL)
+           db_printf(" count %u leader %p tty %p sid %d login %s",
+               tp->t_session->s_count, tp->t_session->s_leader,
+               tp->t_session->s_ttyp, tp->t_session->s_sid,
+               tp->t_session->s_login);
+       db_printf("\n");
+       db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
+       db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
+       db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
+       db_printf("\tdev: %p\n", tp->t_dev);
+}
+
+/* DDB command to list TTYs. */
+DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
+{
+       struct tty *tp;
+       size_t isiz, osiz;
+       int i, j;
+
+       /* Make the output look like `pstat -t'. */
+       db_printf("PTR        ");
+#if defined(__LP64__)
+       db_printf("        ");
+#endif
+       db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
+           "COL  SESS  PGID STATE\n");
+
+       TAILQ_FOREACH(tp, &tty_list, t_list) {
+               isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
+               osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
+
+               db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
+                   "%5d ", tp, tty_devname(tp), isiz,
+                   tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
+                   tp->t_inq.ti_end - tp->t_inq.ti_linestart,
+                   isiz - tp->t_inlow, osiz,
+                   tp->t_outq.to_end - tp->t_outq.to_begin,
+                   osiz - tp->t_outlow, MIN(tp->t_column, 99999),
+                   tp->t_session ? tp->t_session->s_sid : 0,
+                   tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
+
+               /* Flag bits. */
+               for (i = j = 0; ttystates[i].flag; i++)
+                       if (tp->t_flags & ttystates[i].flag) {
+                               db_printf("%c", ttystates[i].val);
+                               j++;
+                       }
+               if (j == 0)
+                       db_printf("-");
+               db_printf("\n");
+       }
+}
+#endif /* DDB */
diff --git a/freebsd/sys/kern/tty_inq.c b/freebsd/sys/kern/tty_inq.c
new file mode 100644
index 0000000..00a1336
--- /dev/null
+++ b/freebsd/sys/kern/tty_inq.c
@@ -0,0 +1,491 @@
+#include <machine/rtems-bsd-kernel-space.h>
+
+/*-
+ * Copyright (c) 2008 Ed Schouten <e...@freebsd.org>
+ * All rights reserved.
+ *
+ * Portions of this software were developed under sponsorship from Snow
+ * B.V., the Netherlands.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/sys/param.h>
+#include <sys/kernel.h>
+#include <rtems/bsd/sys/lock.h>
+#include <sys/queue.h>
+#include <sys/sysctl.h>
+#include <sys/systm.h>
+#include <sys/tty.h>
+#include <sys/uio.h>
+
+#include <vm/uma.h>
+
+/*
+ * TTY input queue buffering.
+ *
+ * Unlike the output queue, the input queue has more features that are
+ * needed to properly implement various features offered by the TTY
+ * interface:
+ *
+ * - Data can be removed from the tail of the queue, which is used to
+ *   implement backspace.
+ * - Once in a while, input has to be `canonicalized'. When ICANON is
+ *   turned on, this will be done after a CR has been inserted.
+ *   Otherwise, it should be done after any character has been inserted.
+ * - The input queue can store one bit per byte, called the quoting bit.
+ *   This bit is used by TTYDISC to make backspace work on quoted
+ *   characters.
+ *
+ * In most cases, there is probably less input than output, so unlike
+ * the outq, we'll stick to 128 byte blocks here.
+ */
+
+static int ttyinq_flush_secure = 1;
+SYSCTL_INT(_kern, OID_AUTO, tty_inq_flush_secure, CTLFLAG_RW,
+       &ttyinq_flush_secure, 0, "Zero buffers while flushing");
+
+#define TTYINQ_QUOTESIZE       (TTYINQ_DATASIZE / BMSIZE)
+#define BMSIZE                 32
+#define GETBIT(tib,boff) \
+       ((tib)->tib_quotes[(boff) / BMSIZE] & (1 << ((boff) % BMSIZE)))
+#define SETBIT(tib,boff) \
+       ((tib)->tib_quotes[(boff) / BMSIZE] |= (1 << ((boff) % BMSIZE)))
+#define CLRBIT(tib,boff) \
+       ((tib)->tib_quotes[(boff) / BMSIZE] &= ~(1 << ((boff) % BMSIZE)))
+
+struct ttyinq_block {
+       struct ttyinq_block     *tib_prev;
+       struct ttyinq_block     *tib_next;
+       uint32_t                tib_quotes[TTYINQ_QUOTESIZE];
+       char                    tib_data[TTYINQ_DATASIZE];
+};
+
+static uma_zone_t ttyinq_zone;
+
+#define        TTYINQ_INSERT_TAIL(ti, tib) do {                                
\
+       if (ti->ti_end == 0) {                                          \
+               tib->tib_prev = NULL;                                   \
+               tib->tib_next = ti->ti_firstblock;                      \
+               ti->ti_firstblock = tib;                                \
+       } else {                                                        \
+               tib->tib_prev = ti->ti_lastblock;                       \
+               tib->tib_next = ti->ti_lastblock->tib_next;             \
+               ti->ti_lastblock->tib_next = tib;                       \
+       }                                                               \
+       if (tib->tib_next != NULL)                                      \
+               tib->tib_next->tib_prev = tib;                          \
+       ti->ti_nblocks++;                                               \
+} while (0)
+
+#define        TTYINQ_REMOVE_HEAD(ti) do {                                     
\
+       ti->ti_firstblock = ti->ti_firstblock->tib_next;                \
+       if (ti->ti_firstblock != NULL)                                  \
+               ti->ti_firstblock->tib_prev = NULL;                     \
+       ti->ti_nblocks--;                                               \
+} while (0)
+
+#define        TTYINQ_RECYCLE(ti, tib) do {                                    
\
+       if (ti->ti_quota <= ti->ti_nblocks)                             \
+               uma_zfree(ttyinq_zone, tib);                            \
+       else                                                            \
+               TTYINQ_INSERT_TAIL(ti, tib);                            \
+} while (0)
+
+void
+ttyinq_setsize(struct ttyinq *ti, struct tty *tp, size_t size)
+{
+       struct ttyinq_block *tib;
+
+       ti->ti_quota = howmany(size, TTYINQ_DATASIZE);
+
+       while (ti->ti_quota > ti->ti_nblocks) {
+               /*
+                * List is getting bigger.
+                * Add new blocks to the tail of the list.
+                *
+                * We must unlock the TTY temporarily, because we need
+                * to allocate memory. This won't be a problem, because
+                * in the worst case, another thread ends up here, which
+                * may cause us to allocate too many blocks, but this
+                * will be caught by the loop below.
+                */
+               tty_unlock(tp);
+               tib = uma_zalloc(ttyinq_zone, M_WAITOK);
+               tty_lock(tp);
+
+               TTYINQ_INSERT_TAIL(ti, tib);
+       }
+}
+
+void
+ttyinq_free(struct ttyinq *ti)
+{
+       struct ttyinq_block *tib;
+
+       ttyinq_flush(ti);
+       ti->ti_quota = 0;
+
+       while ((tib = ti->ti_firstblock) != NULL) {
+               TTYINQ_REMOVE_HEAD(ti);
+               uma_zfree(ttyinq_zone, tib);
+       }
+
+       MPASS(ti->ti_nblocks == 0);
+}
+
+int
+ttyinq_read_uio(struct ttyinq *ti, struct tty *tp, struct uio *uio,
+    size_t rlen, size_t flen)
+{
+
+       MPASS(rlen <= uio->uio_resid);
+
+       while (rlen > 0) {
+               int error;
+               struct ttyinq_block *tib;
+               size_t cbegin, cend, clen;
+
+               /* See if there still is data. */
+               if (ti->ti_begin == ti->ti_linestart)
+                       return (0);
+               tib = ti->ti_firstblock;
+               if (tib == NULL)
+                       return (0);
+
+               /*
+                * The end address should be the lowest of these three:
+                * - The write pointer
+                * - The blocksize - we can't read beyond the block
+                * - The end address if we could perform the full read
+                */
+               cbegin = ti->ti_begin;
+               cend = MIN(MIN(ti->ti_linestart, ti->ti_begin + rlen),
+                   TTYINQ_DATASIZE);
+               clen = cend - cbegin;
+               MPASS(clen >= flen);
+               rlen -= clen;
+
+               /*
+                * We can prevent buffering in some cases:
+                * - We need to read the block until the end.
+                * - We don't need to read the block until the end, but
+                *   there is no data beyond it, which allows us to move
+                *   the write pointer to a new block.
+                */
+               if (cend == TTYINQ_DATASIZE || cend == ti->ti_end) {
+                       /*
+                        * Fast path: zero copy. Remove the first block,
+                        * so we can unlock the TTY temporarily.
+                        */
+                       TTYINQ_REMOVE_HEAD(ti);
+                       ti->ti_begin = 0;
+
+                       /*
+                        * Because we remove the first block, we must
+                        * fix up the block offsets.
+                        */
+#define CORRECT_BLOCK(t) do {                  \
+       if (t <= TTYINQ_DATASIZE)               \
+               t = 0;                          \
+       else                                    \
+               t -= TTYINQ_DATASIZE;           \
+} while (0)
+                       CORRECT_BLOCK(ti->ti_linestart);
+                       CORRECT_BLOCK(ti->ti_reprint);
+                       CORRECT_BLOCK(ti->ti_end);
+#undef CORRECT_BLOCK
+
+                       /*
+                        * Temporary unlock and copy the data to
+                        * userspace. We may need to flush trailing
+                        * bytes, like EOF characters.
+                        */
+                       tty_unlock(tp);
+                       error = uiomove(tib->tib_data + cbegin,
+                           clen - flen, uio);
+                       tty_lock(tp);
+
+                       /* Block can now be readded to the list. */
+                       TTYINQ_RECYCLE(ti, tib);
+               } else {
+                       char ob[TTYINQ_DATASIZE - 1];
+
+                       /*
+                        * Slow path: store data in a temporary buffer.
+                        */
+                       memcpy(ob, tib->tib_data + cbegin, clen - flen);
+                       ti->ti_begin += clen;
+                       MPASS(ti->ti_begin < TTYINQ_DATASIZE);
+
+                       /* Temporary unlock and copy the data to userspace. */
+                       tty_unlock(tp);
+                       error = uiomove(ob, clen - flen, uio);
+                       tty_lock(tp);
+               }
+
+               if (error != 0)
+                       return (error);
+               if (tty_gone(tp))
+                       return (ENXIO);
+       }
+
+       return (0);
+}
+
+static __inline void
+ttyinq_set_quotes(struct ttyinq_block *tib, size_t offset,
+    size_t length, int value)
+{
+
+       if (value) {
+               /* Set the bits. */
+               for (; length > 0; length--, offset++)
+                       SETBIT(tib, offset);
+       } else {
+               /* Unset the bits. */
+               for (; length > 0; length--, offset++)
+                       CLRBIT(tib, offset);
+       }
+}
+
+size_t
+ttyinq_write(struct ttyinq *ti, const void *buf, size_t nbytes, int quote)
+{
+       const char *cbuf = buf;
+       struct ttyinq_block *tib;
+       unsigned int boff;
+       size_t l;
+
+       while (nbytes > 0) {
+               boff = ti->ti_end % TTYINQ_DATASIZE;
+
+               if (ti->ti_end == 0) {
+                       /* First time we're being used or drained. */
+                       MPASS(ti->ti_begin == 0);
+                       tib = ti->ti_firstblock;
+                       if (tib == NULL) {
+                               /* Queue has no blocks. */
+                               break;
+                       }
+                       ti->ti_lastblock = tib;
+               } else if (boff == 0) {
+                       /* We reached the end of this block on last write. */
+                       tib = ti->ti_lastblock->tib_next;
+                       if (tib == NULL) {
+                               /* We've reached the watermark. */
+                               break;
+                       }
+                       ti->ti_lastblock = tib;
+               } else {
+                       tib = ti->ti_lastblock;
+               }
+
+               /* Don't copy more than was requested. */
+               l = MIN(nbytes, TTYINQ_DATASIZE - boff);
+               MPASS(l > 0);
+               memcpy(tib->tib_data + boff, cbuf, l);
+
+               /* Set the quoting bits for the proper region. */
+               ttyinq_set_quotes(tib, boff, l, quote);
+
+               cbuf += l;
+               nbytes -= l;
+               ti->ti_end += l;
+       }
+
+       return (cbuf - (const char *)buf);
+}
+
+int
+ttyinq_write_nofrag(struct ttyinq *ti, const void *buf, size_t nbytes, int 
quote)
+{
+       size_t ret;
+
+       if (ttyinq_bytesleft(ti) < nbytes)
+               return (-1);
+
+       /* We should always be able to write it back. */
+       ret = ttyinq_write(ti, buf, nbytes, quote);
+       MPASS(ret == nbytes);
+
+       return (0);
+}
+
+void
+ttyinq_canonicalize(struct ttyinq *ti)
+{
+
+       ti->ti_linestart = ti->ti_reprint = ti->ti_end;
+       ti->ti_startblock = ti->ti_reprintblock = ti->ti_lastblock;
+}
+
+size_t
+ttyinq_findchar(struct ttyinq *ti, const char *breakc, size_t maxlen,
+    char *lastc)
+{
+       struct ttyinq_block *tib = ti->ti_firstblock;
+       unsigned int boff = ti->ti_begin;
+       unsigned int bend = MIN(MIN(TTYINQ_DATASIZE, ti->ti_linestart),
+           ti->ti_begin + maxlen);
+
+       MPASS(maxlen > 0);
+
+       if (tib == NULL)
+               return (0);
+
+       while (boff < bend) {
+               if (strchr(breakc, tib->tib_data[boff]) && !GETBIT(tib, boff)) {
+                       *lastc = tib->tib_data[boff];
+                       return (boff - ti->ti_begin + 1);
+               }
+               boff++;
+       }
+
+       /* Not found - just process the entire block. */
+       return (bend - ti->ti_begin);
+}
+
+void
+ttyinq_flush(struct ttyinq *ti)
+{
+       struct ttyinq_block *tib;
+
+       ti->ti_begin = 0;
+       ti->ti_linestart = 0;
+       ti->ti_reprint = 0;
+       ti->ti_end = 0;
+
+       /* Zero all data in the input queue to get rid of passwords. */
+       if (ttyinq_flush_secure) {
+               for (tib = ti->ti_firstblock; tib != NULL; tib = tib->tib_next)
+                       bzero(&tib->tib_data, sizeof tib->tib_data);
+       }
+}
+
+int
+ttyinq_peekchar(struct ttyinq *ti, char *c, int *quote)
+{
+       unsigned int boff;
+       struct ttyinq_block *tib = ti->ti_lastblock;
+
+       if (ti->ti_linestart == ti->ti_end)
+               return (-1);
+
+       MPASS(ti->ti_end > 0);
+       boff = (ti->ti_end - 1) % TTYINQ_DATASIZE;
+
+       *c = tib->tib_data[boff];
+       *quote = GETBIT(tib, boff);
+
+       return (0);
+}
+
+void
+ttyinq_unputchar(struct ttyinq *ti)
+{
+
+       MPASS(ti->ti_linestart < ti->ti_end);
+
+       if (--ti->ti_end % TTYINQ_DATASIZE == 0) {
+               /* Roll back to the previous block. */
+               ti->ti_lastblock = ti->ti_lastblock->tib_prev;
+               /*
+                * This can only fail if we are unputchar()'ing the
+                * first character in the queue.
+                */
+               MPASS((ti->ti_lastblock == NULL) == (ti->ti_end == 0));
+       }
+}
+
+void
+ttyinq_reprintpos_set(struct ttyinq *ti)
+{
+
+       ti->ti_reprint = ti->ti_end;
+       ti->ti_reprintblock = ti->ti_lastblock;
+}
+
+void
+ttyinq_reprintpos_reset(struct ttyinq *ti)
+{
+
+       ti->ti_reprint = ti->ti_linestart;
+       ti->ti_reprintblock = ti->ti_startblock;
+}
+
+static void
+ttyinq_line_iterate(struct ttyinq *ti,
+    ttyinq_line_iterator_t *iterator, void *data,
+    unsigned int offset, struct ttyinq_block *tib)
+{
+       unsigned int boff;
+
+       /* Use the proper block when we're at the queue head. */
+       if (offset == 0)
+               tib = ti->ti_firstblock;
+
+       /* Iterate all characters and call the iterator function. */
+       for (; offset < ti->ti_end; offset++) {
+               boff = offset % TTYINQ_DATASIZE;
+               MPASS(tib != NULL);
+
+               /* Call back the iterator function. */
+               iterator(data, tib->tib_data[boff], GETBIT(tib, boff));
+
+               /* Last byte iterated - go to the next block. */
+               if (boff == TTYINQ_DATASIZE - 1)
+                       tib = tib->tib_next;
+               MPASS(tib != NULL);
+       }
+}
+
+void
+ttyinq_line_iterate_from_linestart(struct ttyinq *ti,
+    ttyinq_line_iterator_t *iterator, void *data)
+{
+
+       ttyinq_line_iterate(ti, iterator, data,
+           ti->ti_linestart, ti->ti_startblock);
+}
+
+void
+ttyinq_line_iterate_from_reprintpos(struct ttyinq *ti,
+    ttyinq_line_iterator_t *iterator, void *data)
+{
+
+       ttyinq_line_iterate(ti, iterator, data,
+           ti->ti_reprint, ti->ti_reprintblock);
+}
+
+static void
+ttyinq_startup(void *dummy)
+{
+
+       ttyinq_zone = uma_zcreate("ttyinq", sizeof(struct ttyinq_block),
+           NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
+}
+
+SYSINIT(ttyinq, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyinq_startup, NULL);
diff --git a/freebsd/sys/kern/tty_outq.c b/freebsd/sys/kern/tty_outq.c
new file mode 100644
index 0000000..a7d1a6e
--- /dev/null
+++ b/freebsd/sys/kern/tty_outq.c
@@ -0,0 +1,341 @@
+#include <machine/rtems-bsd-kernel-space.h>
+
+/*-
+ * Copyright (c) 2008 Ed Schouten <e...@freebsd.org>
+ * All rights reserved.
+ *
+ * Portions of this software were developed under sponsorship from Snow
+ * B.V., the Netherlands.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/sys/param.h>
+#include <sys/kernel.h>
+#include <rtems/bsd/sys/lock.h>
+#include <sys/queue.h>
+#include <sys/systm.h>
+#include <sys/tty.h>
+#include <sys/uio.h>
+
+#include <vm/uma.h>
+
+/*
+ * TTY output queue buffering.
+ *
+ * The previous design of the TTY layer offered the so-called clists.
+ * These clists were used for both the input queues and the output
+ * queue. We don't use certain features on the output side, like quoting
+ * bits for parity marking and such. This mechanism is similar to the
+ * old clists, but only contains the features we need to buffer the
+ * output.
+ */
+
+struct ttyoutq_block {
+       struct ttyoutq_block    *tob_next;
+       char                    tob_data[TTYOUTQ_DATASIZE];
+};
+
+static uma_zone_t ttyoutq_zone;
+
+#define        TTYOUTQ_INSERT_TAIL(to, tob) do {                               
\
+       if (to->to_end == 0) {                                          \
+               tob->tob_next = to->to_firstblock;                      \
+               to->to_firstblock = tob;                                \
+       } else {                                                        \
+               tob->tob_next = to->to_lastblock->tob_next;             \
+               to->to_lastblock->tob_next = tob;                       \
+       }                                                               \
+       to->to_nblocks++;                                               \
+} while (0)
+
+#define        TTYOUTQ_REMOVE_HEAD(to) do {                                    
\
+       to->to_firstblock = to->to_firstblock->tob_next;                \
+       to->to_nblocks--;                                               \
+} while (0)
+
+#define        TTYOUTQ_RECYCLE(to, tob) do {                                   
\
+       if (to->to_quota <= to->to_nblocks)                             \
+               uma_zfree(ttyoutq_zone, tob);                           \
+       else                                                            \
+               TTYOUTQ_INSERT_TAIL(to, tob);                           \
+} while(0)
+
+void
+ttyoutq_flush(struct ttyoutq *to)
+{
+
+       to->to_begin = 0;
+       to->to_end = 0;
+}
+
+void
+ttyoutq_setsize(struct ttyoutq *to, struct tty *tp, size_t size)
+{
+       struct ttyoutq_block *tob;
+
+       to->to_quota = howmany(size, TTYOUTQ_DATASIZE);
+
+       while (to->to_quota > to->to_nblocks) {
+               /*
+                * List is getting bigger.
+                * Add new blocks to the tail of the list.
+                *
+                * We must unlock the TTY temporarily, because we need
+                * to allocate memory. This won't be a problem, because
+                * in the worst case, another thread ends up here, which
+                * may cause us to allocate too many blocks, but this
+                * will be caught by the loop below.
+                */
+               tty_unlock(tp);
+               tob = uma_zalloc(ttyoutq_zone, M_WAITOK);
+               tty_lock(tp);
+
+               TTYOUTQ_INSERT_TAIL(to, tob);
+       }
+}
+
+void
+ttyoutq_free(struct ttyoutq *to)
+{
+       struct ttyoutq_block *tob;
+
+       ttyoutq_flush(to);
+       to->to_quota = 0;
+
+       while ((tob = to->to_firstblock) != NULL) {
+               TTYOUTQ_REMOVE_HEAD(to);
+               uma_zfree(ttyoutq_zone, tob);
+       }
+
+       MPASS(to->to_nblocks == 0);
+}
+
+size_t
+ttyoutq_read(struct ttyoutq *to, void *buf, size_t len)
+{
+       char *cbuf = buf;
+
+       while (len > 0) {
+               struct ttyoutq_block *tob;
+               size_t cbegin, cend, clen;
+
+               /* See if there still is data. */
+               if (to->to_begin == to->to_end)
+                       break;
+               tob = to->to_firstblock;
+               if (tob == NULL)
+                       break;
+
+               /*
+                * The end address should be the lowest of these three:
+                * - The write pointer
+                * - The blocksize - we can't read beyond the block
+                * - The end address if we could perform the full read
+                */
+               cbegin = to->to_begin;
+               cend = MIN(MIN(to->to_end, to->to_begin + len),
+                   TTYOUTQ_DATASIZE);
+               clen = cend - cbegin;
+
+               /* Copy the data out of the buffers. */
+               memcpy(cbuf, tob->tob_data + cbegin, clen);
+               cbuf += clen;
+               len -= clen;
+
+               if (cend == to->to_end) {
+                       /* Read the complete queue. */
+                       to->to_begin = 0;
+                       to->to_end = 0;
+               } else if (cend == TTYOUTQ_DATASIZE) {
+                       /* Read the block until the end. */
+                       TTYOUTQ_REMOVE_HEAD(to);
+                       to->to_begin = 0;
+                       to->to_end -= TTYOUTQ_DATASIZE;
+                       TTYOUTQ_RECYCLE(to, tob);
+               } else {
+                       /* Read the block partially. */
+                       to->to_begin += clen;
+               }
+       }
+
+       return (cbuf - (char *)buf);
+}
+
+/*
+ * An optimized version of ttyoutq_read() which can be used in pseudo
+ * TTY drivers to directly copy data from the outq to userspace, instead
+ * of buffering it.
+ *
+ * We can only copy data directly if we need to read the entire block
+ * back to the user, because we temporarily remove the block from the
+ * queue. Otherwise we need to copy it to a temporary buffer first, to
+ * make sure data remains in the correct order.
+ */
+int
+ttyoutq_read_uio(struct ttyoutq *to, struct tty *tp, struct uio *uio)
+{
+
+       while (uio->uio_resid > 0) {
+               int error;
+               struct ttyoutq_block *tob;
+               size_t cbegin, cend, clen;
+
+               /* See if there still is data. */
+               if (to->to_begin == to->to_end)
+                       return (0);
+               tob = to->to_firstblock;
+               if (tob == NULL)
+                       return (0);
+
+               /*
+                * The end address should be the lowest of these three:
+                * - The write pointer
+                * - The blocksize - we can't read beyond the block
+                * - The end address if we could perform the full read
+                */
+               cbegin = to->to_begin;
+               cend = MIN(MIN(to->to_end, to->to_begin + uio->uio_resid),
+                   TTYOUTQ_DATASIZE);
+               clen = cend - cbegin;
+
+               /*
+                * We can prevent buffering in some cases:
+                * - We need to read the block until the end.
+                * - We don't need to read the block until the end, but
+                *   there is no data beyond it, which allows us to move
+                *   the write pointer to a new block.
+                */
+               if (cend == TTYOUTQ_DATASIZE || cend == to->to_end) {
+                       /*
+                        * Fast path: zero copy. Remove the first block,
+                        * so we can unlock the TTY temporarily.
+                        */
+                       TTYOUTQ_REMOVE_HEAD(to);
+                       to->to_begin = 0;
+                       if (to->to_end <= TTYOUTQ_DATASIZE)
+                               to->to_end = 0;
+                       else
+                               to->to_end -= TTYOUTQ_DATASIZE;
+
+                       /* Temporary unlock and copy the data to userspace. */
+                       tty_unlock(tp);
+                       error = uiomove(tob->tob_data + cbegin, clen, uio);
+                       tty_lock(tp);
+
+                       /* Block can now be readded to the list. */
+                       TTYOUTQ_RECYCLE(to, tob);
+               } else {
+                       char ob[TTYOUTQ_DATASIZE - 1];
+
+                       /*
+                        * Slow path: store data in a temporary buffer.
+                        */
+                       memcpy(ob, tob->tob_data + cbegin, clen);
+                       to->to_begin += clen;
+                       MPASS(to->to_begin < TTYOUTQ_DATASIZE);
+
+                       /* Temporary unlock and copy the data to userspace. */
+                       tty_unlock(tp);
+                       error = uiomove(ob, clen, uio);
+                       tty_lock(tp);
+               }
+
+               if (error != 0)
+                       return (error);
+       }
+
+       return (0);
+}
+
+size_t
+ttyoutq_write(struct ttyoutq *to, const void *buf, size_t nbytes)
+{
+       const char *cbuf = buf;
+       struct ttyoutq_block *tob;
+       unsigned int boff;
+       size_t l;
+
+       while (nbytes > 0) {
+               boff = to->to_end % TTYOUTQ_DATASIZE;
+
+               if (to->to_end == 0) {
+                       /* First time we're being used or drained. */
+                       MPASS(to->to_begin == 0);
+                       tob = to->to_firstblock;
+                       if (tob == NULL) {
+                               /* Queue has no blocks. */
+                               break;
+                       }
+                       to->to_lastblock = tob;
+               } else if (boff == 0) {
+                       /* We reached the end of this block on last write. */
+                       tob = to->to_lastblock->tob_next;
+                       if (tob == NULL) {
+                               /* We've reached the watermark. */
+                               break;
+                       }
+                       to->to_lastblock = tob;
+               } else {
+                       tob = to->to_lastblock;
+               }
+
+               /* Don't copy more than was requested. */
+               l = MIN(nbytes, TTYOUTQ_DATASIZE - boff);
+               MPASS(l > 0);
+               memcpy(tob->tob_data + boff, cbuf, l);
+
+               cbuf += l;
+               nbytes -= l;
+               to->to_end += l;
+       }
+
+       return (cbuf - (const char *)buf);
+}
+
+int
+ttyoutq_write_nofrag(struct ttyoutq *to, const void *buf, size_t nbytes)
+{
+       size_t ret;
+
+       if (ttyoutq_bytesleft(to) < nbytes)
+               return (-1);
+
+       /* We should always be able to write it back. */
+       ret = ttyoutq_write(to, buf, nbytes);
+       MPASS(ret == nbytes);
+
+       return (0);
+}
+
+static void
+ttyoutq_startup(void *dummy)
+{
+
+       ttyoutq_zone = uma_zcreate("ttyoutq", sizeof(struct ttyoutq_block),
+           NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
+}
+
+SYSINIT(ttyoutq, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyoutq_startup, NULL);
diff --git a/freebsd/sys/kern/tty_ttydisc.c b/freebsd/sys/kern/tty_ttydisc.c
new file mode 100644
index 0000000..edb1d15
--- /dev/null
+++ b/freebsd/sys/kern/tty_ttydisc.c
@@ -0,0 +1,1267 @@
+#include <machine/rtems-bsd-kernel-space.h>
+
+/*-
+ * Copyright (c) 2008 Ed Schouten <e...@freebsd.org>
+ * All rights reserved.
+ *
+ * Portions of this software were developed under sponsorship from Snow
+ * B.V., the Netherlands.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/sys/param.h>
+#include <sys/fcntl.h>
+#include <sys/filio.h>
+#include <sys/kernel.h>
+#include <sys/signal.h>
+#include <sys/sysctl.h>
+#include <sys/systm.h>
+#include <sys/tty.h>
+#include <sys/ttycom.h>
+#include <sys/ttydefaults.h>
+#include <sys/uio.h>
+#include <sys/vnode.h>
+
+/*
+ * Standard TTYDISC `termios' line discipline.
+ */
+
+/* Statistics. */
+static unsigned long tty_nin = 0;
+SYSCTL_ULONG(_kern, OID_AUTO, tty_nin, CTLFLAG_RD,
+       &tty_nin, 0, "Total amount of bytes received");
+static unsigned long tty_nout = 0;
+SYSCTL_ULONG(_kern, OID_AUTO, tty_nout, CTLFLAG_RD,
+       &tty_nout, 0, "Total amount of bytes transmitted");
+
+/* termios comparison macro's. */
+#define        CMP_CC(v,c) (tp->t_termios.c_cc[v] != _POSIX_VDISABLE && \
+                       tp->t_termios.c_cc[v] == (c))
+#define        CMP_FLAG(field,opt) (tp->t_termios.c_ ## field ## flag & (opt))
+
+/* Characters that cannot be modified through c_cc. */
+#define CTAB   '\t'
+#define CNL    '\n'
+#define CCR    '\r'
+
+/* Character is a control character. */
+#define CTL_VALID(c)   ((c) == 0x7f || (unsigned char)(c) < 0x20)
+/* Control character should be processed on echo. */
+#define CTL_ECHO(c,q)  (!(q) && ((c) == CERASE2 || (c) == CTAB || \
+    (c) == CNL || (c) == CCR))
+/* Control character should be printed using ^X notation. */
+#define CTL_PRINT(c,q) ((c) == 0x7f || ((unsigned char)(c) < 0x20 && \
+    ((q) || ((c) != CTAB && (c) != CNL))))
+/* Character is whitespace. */
+#define CTL_WHITE(c)   ((c) == ' ' || (c) == CTAB)
+/* Character is alphanumeric. */
+#define CTL_ALNUM(c)   (((c) >= '0' && (c) <= '9') || \
+    ((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
+
+#define        TTY_STACKBUF    256
+
+void
+ttydisc_open(struct tty *tp)
+{
+       ttydisc_optimize(tp);
+}
+
+void
+ttydisc_close(struct tty *tp)
+{
+
+       /* Clean up our flags when leaving the discipline. */
+       tp->t_flags &= ~(TF_STOPPED|TF_HIWAT|TF_ZOMBIE);
+
+       /*
+        * POSIX states that we must drain output and flush input on
+        * last close.  Draining has already been done if possible.
+        */
+       tty_flush(tp, FREAD | FWRITE);
+
+       if (ttyhook_hashook(tp, close))
+               ttyhook_close(tp);
+}
+
+static int
+ttydisc_read_canonical(struct tty *tp, struct uio *uio, int ioflag)
+{
+       char breakc[4] = { CNL }; /* enough to hold \n, VEOF and VEOL. */
+       int error;
+       size_t clen, flen = 0, n = 1;
+       unsigned char lastc = _POSIX_VDISABLE;
+
+#define BREAK_ADD(c) do { \
+       if (tp->t_termios.c_cc[c] != _POSIX_VDISABLE)   \
+               breakc[n++] = tp->t_termios.c_cc[c];    \
+} while (0)
+       /* Determine which characters we should trigger on. */
+       BREAK_ADD(VEOF);
+       BREAK_ADD(VEOL);
+#undef BREAK_ADD
+       breakc[n] = '\0';
+
+       do {
+               error = tty_wait_background(tp, curthread, SIGTTIN);
+               if (error)
+                       return (error);
+
+               /*
+                * Quite a tricky case: unlike the old TTY
+                * implementation, this implementation copies data back
+                * to userspace in large chunks. Unfortunately, we can't
+                * calculate the line length on beforehand if it crosses
+                * ttyinq_block boundaries, because multiple reads could
+                * then make this code read beyond the newline.
+                *
+                * This is why we limit the read to:
+                * - The size the user has requested
+                * - The blocksize (done in tty_inq.c)
+                * - The amount of bytes until the newline
+                *
+                * This causes the line length to be recalculated after
+                * each block has been copied to userspace. This will
+                * cause the TTY layer to return data in chunks using
+                * the blocksize (except the first and last blocks).
+                */
+               clen = ttyinq_findchar(&tp->t_inq, breakc, uio->uio_resid,
+                   &lastc);
+
+               /* No more data. */
+               if (clen == 0) {
+                       if (tp->t_flags & TF_ZOMBIE)
+                               return (0);
+                       else if (ioflag & IO_NDELAY)
+                               return (EWOULDBLOCK);
+
+                       error = tty_wait(tp, &tp->t_inwait);
+                       if (error)
+                               return (error);
+                       continue;
+               }
+
+               /* Don't send the EOF char back to userspace. */
+               if (CMP_CC(VEOF, lastc))
+                       flen = 1;
+
+               MPASS(flen <= clen);
+
+               /* Read and throw away the EOF character. */
+               error = ttyinq_read_uio(&tp->t_inq, tp, uio, clen, flen);
+               if (error)
+                       return (error);
+
+       } while (uio->uio_resid > 0 && lastc == _POSIX_VDISABLE);
+
+       return (0);
+}
+
+static int
+ttydisc_read_raw_no_timer(struct tty *tp, struct uio *uio, int ioflag)
+{
+       size_t vmin = tp->t_termios.c_cc[VMIN];
+       ssize_t oresid = uio->uio_resid;
+       int error;
+
+       MPASS(tp->t_termios.c_cc[VTIME] == 0);
+
+       /*
+        * This routine implements the easy cases of read()s while in
+        * non-canonical mode, namely case B and D, where we don't have
+        * any timers at all.
+        */
+
+       for (;;) {
+               error = tty_wait_background(tp, curthread, SIGTTIN);
+               if (error)
+                       return (error);
+
+               error = ttyinq_read_uio(&tp->t_inq, tp, uio,
+                   uio->uio_resid, 0);
+               if (error)
+                       return (error);
+               if (uio->uio_resid == 0 || (oresid - uio->uio_resid) >= vmin)
+                       return (0);
+
+               /* We have to wait for more. */
+               if (tp->t_flags & TF_ZOMBIE)
+                       return (0);
+               else if (ioflag & IO_NDELAY)
+                       return (EWOULDBLOCK);
+
+               error = tty_wait(tp, &tp->t_inwait);
+               if (error)
+                       return (error);
+       }
+}
+
+static int
+ttydisc_read_raw_read_timer(struct tty *tp, struct uio *uio, int ioflag,
+    int oresid)
+{
+       size_t vmin = MAX(tp->t_termios.c_cc[VMIN], 1);
+       unsigned int vtime = tp->t_termios.c_cc[VTIME];
+       struct timeval end, now, left;
+       int error, hz;
+
+       MPASS(tp->t_termios.c_cc[VTIME] != 0);
+
+       /* Determine when the read should be expired. */
+       end.tv_sec = vtime / 10;
+       end.tv_usec = (vtime % 10) * 100000;
+       getmicrotime(&now);
+       timevaladd(&end, &now);
+
+       for (;;) {
+               error = tty_wait_background(tp, curthread, SIGTTIN);
+               if (error)
+                       return (error);
+
+               error = ttyinq_read_uio(&tp->t_inq, tp, uio,
+                   uio->uio_resid, 0);
+               if (error)
+                       return (error);
+               if (uio->uio_resid == 0 || (oresid - uio->uio_resid) >= vmin)
+                       return (0);
+
+               /* Calculate how long we should wait. */
+               getmicrotime(&now);
+               if (timevalcmp(&now, &end, >))
+                       return (0);
+               left = end;
+               timevalsub(&left, &now);
+               hz = tvtohz(&left);
+
+               /*
+                * We have to wait for more. If the timer expires, we
+                * should return a 0-byte read.
+                */
+               if (tp->t_flags & TF_ZOMBIE)
+                       return (0);
+               else if (ioflag & IO_NDELAY)
+                       return (EWOULDBLOCK);
+
+               error = tty_timedwait(tp, &tp->t_inwait, hz);
+               if (error)
+                       return (error == EWOULDBLOCK ? 0 : error);
+       }
+
+       return (0);
+}
+
+static int
+ttydisc_read_raw_interbyte_timer(struct tty *tp, struct uio *uio, int ioflag)
+{
+       size_t vmin = tp->t_termios.c_cc[VMIN];
+       ssize_t oresid = uio->uio_resid;
+       int error;
+
+       MPASS(tp->t_termios.c_cc[VMIN] != 0);
+       MPASS(tp->t_termios.c_cc[VTIME] != 0);
+
+       /*
+        * When using the interbyte timer, the timer should be started
+        * after the first byte has been received. We just call into the
+        * generic read timer code after we've received the first byte.
+        */
+
+       for (;;) {
+               error = tty_wait_background(tp, curthread, SIGTTIN);
+               if (error)
+                       return (error);
+
+               error = ttyinq_read_uio(&tp->t_inq, tp, uio,
+                   uio->uio_resid, 0);
+               if (error)
+                       return (error);
+               if (uio->uio_resid == 0 || (oresid - uio->uio_resid) >= vmin)
+                       return (0);
+
+               /*
+                * Not enough data, but we did receive some, which means
+                * we'll now start using the interbyte timer.
+                */
+               if (oresid != uio->uio_resid)
+                       break;
+
+               /* We have to wait for more. */
+               if (tp->t_flags & TF_ZOMBIE)
+                       return (0);
+               else if (ioflag & IO_NDELAY)
+                       return (EWOULDBLOCK);
+
+               error = tty_wait(tp, &tp->t_inwait);
+               if (error)
+                       return (error);
+       }
+
+       return ttydisc_read_raw_read_timer(tp, uio, ioflag, oresid);
+}
+
+int
+ttydisc_read(struct tty *tp, struct uio *uio, int ioflag)
+{
+       int error;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (uio->uio_resid == 0)
+               return (0);
+
+       if (CMP_FLAG(l, ICANON))
+               error = ttydisc_read_canonical(tp, uio, ioflag);
+       else if (tp->t_termios.c_cc[VTIME] == 0)
+               error = ttydisc_read_raw_no_timer(tp, uio, ioflag);
+       else if (tp->t_termios.c_cc[VMIN] == 0)
+               error = ttydisc_read_raw_read_timer(tp, uio, ioflag,
+                   uio->uio_resid);
+       else
+               error = ttydisc_read_raw_interbyte_timer(tp, uio, ioflag);
+
+       if (ttyinq_bytesleft(&tp->t_inq) >= tp->t_inlow ||
+           ttyinq_bytescanonicalized(&tp->t_inq) == 0) {
+               /* Unset the input watermark when we've got enough space. */
+               tty_hiwat_in_unblock(tp);
+       }
+
+       return (error);
+}
+
+static __inline unsigned int
+ttydisc_findchar(const char *obstart, unsigned int oblen)
+{
+       const char *c = obstart;
+
+       while (oblen--) {
+               if (CTL_VALID(*c))
+                       break;
+               c++;
+       }
+
+       return (c - obstart);
+}
+
+static int
+ttydisc_write_oproc(struct tty *tp, char c)
+{
+       unsigned int scnt, error;
+
+       MPASS(CMP_FLAG(o, OPOST));
+       MPASS(CTL_VALID(c));
+
+#define PRINT_NORMAL() ttyoutq_write_nofrag(&tp->t_outq, &c, 1)
+       switch (c) {
+       case CEOF:
+               /* End-of-text dropping. */
+               if (CMP_FLAG(o, ONOEOT))
+                       return (0);
+               return PRINT_NORMAL();
+
+       case CERASE2:
+               /* Handle backspace to fix tab expansion. */
+               if (PRINT_NORMAL() != 0)
+                       return (-1);
+               if (tp->t_column > 0)
+                       tp->t_column--;
+               return (0);
+
+       case CTAB:
+               /* Tab expansion. */
+               scnt = 8 - (tp->t_column & 7);
+               if (CMP_FLAG(o, TAB3)) {
+                       error = ttyoutq_write_nofrag(&tp->t_outq,
+                           "        ", scnt);
+               } else {
+                       error = PRINT_NORMAL();
+               }
+               if (error)
+                       return (-1);
+
+               tp->t_column += scnt;
+               MPASS((tp->t_column % 8) == 0);
+               return (0);
+
+       case CNL:
+               /* Newline conversion. */
+               if (CMP_FLAG(o, ONLCR)) {
+                       /* Convert \n to \r\n. */
+                       error = ttyoutq_write_nofrag(&tp->t_outq, "\r\n", 2);
+               } else {
+                       error = PRINT_NORMAL();
+               }
+               if (error)
+                       return (-1);
+
+               if (CMP_FLAG(o, ONLCR|ONLRET)) {
+                       tp->t_column = tp->t_writepos = 0;
+                       ttyinq_reprintpos_set(&tp->t_inq);
+               }
+               return (0);
+
+       case CCR:
+               /* Carriage return to newline conversion. */
+               if (CMP_FLAG(o, OCRNL))
+                       c = CNL;
+               /* Omit carriage returns on column 0. */
+               if (CMP_FLAG(o, ONOCR) && tp->t_column == 0)
+                       return (0);
+               if (PRINT_NORMAL() != 0)
+                       return (-1);
+
+               tp->t_column = tp->t_writepos = 0;
+               ttyinq_reprintpos_set(&tp->t_inq);
+               return (0);
+       }
+
+       /*
+        * Invisible control character. Print it, but don't
+        * increase the column count.
+        */
+       return PRINT_NORMAL();
+#undef PRINT_NORMAL
+}
+
+/*
+ * Just like the old TTY implementation, we need to copy data in chunks
+ * into a temporary buffer. One of the reasons why we need to do this,
+ * is because output processing (only TAB3 though) may allow the buffer
+ * to grow eight times.
+ */
+int
+ttydisc_write(struct tty *tp, struct uio *uio, int ioflag)
+{
+       char ob[TTY_STACKBUF];
+       char *obstart;
+       int error = 0;
+       unsigned int oblen = 0;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tp->t_flags & TF_ZOMBIE)
+               return (EIO);
+
+       /*
+        * We don't need to check whether the process is the foreground
+        * process group or if we have a carrier. This is already done
+        * in ttydev_write().
+        */
+
+       while (uio->uio_resid > 0) {
+               unsigned int nlen;
+
+               MPASS(oblen == 0);
+
+               /* Step 1: read data. */
+               obstart = ob;
+               nlen = MIN(uio->uio_resid, sizeof ob);
+               tty_unlock(tp);
+               error = uiomove(ob, nlen, uio);
+               tty_lock(tp);
+               if (error != 0)
+                       break;
+               oblen = nlen;
+
+               if (tty_gone(tp)) {
+                       error = ENXIO;
+                       break;
+               }
+
+               MPASS(oblen > 0);
+
+               /* Step 2: process data. */
+               do {
+                       unsigned int plen, wlen;
+
+                       /* Search for special characters for post processing. */
+                       if (CMP_FLAG(o, OPOST)) {
+                               plen = ttydisc_findchar(obstart, oblen);
+                       } else {
+                               plen = oblen;
+                       }
+
+                       if (plen == 0) {
+                               /*
+                                * We're going to process a character
+                                * that needs processing
+                                */
+                               if (ttydisc_write_oproc(tp, *obstart) == 0) {
+                                       obstart++;
+                                       oblen--;
+
+                                       tp->t_writepos = tp->t_column;
+                                       ttyinq_reprintpos_set(&tp->t_inq);
+                                       continue;
+                               }
+                       } else {
+                               /* We're going to write regular data. */
+                               wlen = ttyoutq_write(&tp->t_outq, obstart, 
plen);
+                               obstart += wlen;
+                               oblen -= wlen;
+                               tp->t_column += wlen;
+
+                               tp->t_writepos = tp->t_column;
+                               ttyinq_reprintpos_set(&tp->t_inq);
+
+                               if (wlen == plen)
+                                       continue;
+                       }
+
+                       /* Watermark reached. Try to sleep. */
+                       tp->t_flags |= TF_HIWAT_OUT;
+
+                       if (ioflag & IO_NDELAY) {
+                               error = EWOULDBLOCK;
+                               goto done;
+                       }
+
+                       /*
+                        * The driver may write back the data
+                        * synchronously. Be sure to check the high
+                        * water mark before going to sleep.
+                        */
+                       ttydevsw_outwakeup(tp);
+                       if ((tp->t_flags & TF_HIWAT_OUT) == 0)
+                               continue;
+
+                       error = tty_wait(tp, &tp->t_outwait);
+                       if (error)
+                               goto done;
+
+                       if (tp->t_flags & TF_ZOMBIE) {
+                               error = EIO;
+                               goto done;
+                       }
+               } while (oblen > 0);
+       }
+
+done:
+       if (!tty_gone(tp))
+               ttydevsw_outwakeup(tp);
+
+       /*
+        * Add the amount of bytes that we didn't process back to the
+        * uio counters. We need to do this to make sure write() doesn't
+        * count the bytes we didn't store in the queue.
+        */
+       uio->uio_resid += oblen;
+       return (error);
+}
+
+void
+ttydisc_optimize(struct tty *tp)
+{
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (ttyhook_hashook(tp, rint_bypass)) {
+               tp->t_flags |= TF_BYPASS;
+       } else if (ttyhook_hashook(tp, rint)) {
+               tp->t_flags &= ~TF_BYPASS;
+       } else if (!CMP_FLAG(i, ICRNL|IGNCR|IMAXBEL|INLCR|ISTRIP|IXON) &&
+           (!CMP_FLAG(i, BRKINT) || CMP_FLAG(i, IGNBRK)) &&
+           (!CMP_FLAG(i, PARMRK) ||
+               CMP_FLAG(i, IGNPAR|IGNBRK) == (IGNPAR|IGNBRK)) &&
+           !CMP_FLAG(l, ECHO|ICANON|IEXTEN|ISIG|PENDIN)) {
+               tp->t_flags |= TF_BYPASS;
+       } else {
+               tp->t_flags &= ~TF_BYPASS;
+       }
+}
+
+void
+ttydisc_modem(struct tty *tp, int open)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (open)
+               cv_broadcast(&tp->t_dcdwait);
+
+       /*
+        * Ignore modem status lines when CLOCAL is turned on, but don't
+        * enter the zombie state when the TTY isn't opened, because
+        * that would cause the TTY to be in zombie state after being
+        * opened.
+        */
+       if (!tty_opened(tp) || CMP_FLAG(c, CLOCAL))
+               return;
+
+       if (open == 0) {
+               /*
+                * Lost carrier.
+                */
+               tp->t_flags |= TF_ZOMBIE;
+
+               tty_signal_sessleader(tp, SIGHUP);
+               tty_flush(tp, FREAD|FWRITE);
+       } else {
+               /*
+                * Carrier is back again.
+                */
+
+               /* XXX: what should we do here? */
+       }
+}
+
+static int
+ttydisc_echo_force(struct tty *tp, char c, int quote)
+{
+
+       if (CMP_FLAG(o, OPOST) && CTL_ECHO(c, quote)) {
+               /*
+                * Only perform postprocessing when OPOST is turned on
+                * and the character is an unquoted BS/TB/NL/CR.
+                */
+               return ttydisc_write_oproc(tp, c);
+       } else if (CMP_FLAG(l, ECHOCTL) && CTL_PRINT(c, quote)) {
+               /*
+                * Only use ^X notation when ECHOCTL is turned on and
+                * we've got an quoted control character.
+                *
+                * Print backspaces when echoing an end-of-file.
+                */
+               char ob[4] = "^?\b\b";
+
+               /* Print ^X notation. */
+               if (c != 0x7f)
+                       ob[1] = c + 'A' - 1;
+
+               if (!quote && CMP_CC(VEOF, c)) {
+                       return ttyoutq_write_nofrag(&tp->t_outq, ob, 4);
+               } else {
+                       tp->t_column += 2;
+                       return ttyoutq_write_nofrag(&tp->t_outq, ob, 2);
+               }
+       } else {
+               /* Can just be printed. */
+               tp->t_column++;
+               return ttyoutq_write_nofrag(&tp->t_outq, &c, 1);
+       }
+}
+
+static int
+ttydisc_echo(struct tty *tp, char c, int quote)
+{
+
+       /*
+        * Only echo characters when ECHO is turned on, or ECHONL when
+        * the character is an unquoted newline.
+        */
+       if (!CMP_FLAG(l, ECHO) &&
+           (!CMP_FLAG(l, ECHONL) || c != CNL || quote))
+               return (0);
+
+       return ttydisc_echo_force(tp, c, quote);
+}
+
+static void
+ttydisc_reprint_char(void *d, char c, int quote)
+{
+       struct tty *tp = d;
+
+       ttydisc_echo(tp, c, quote);
+}
+
+static void
+ttydisc_reprint(struct tty *tp)
+{
+       cc_t c;
+
+       /* Print  ^R\n, followed by the line. */
+       c = tp->t_termios.c_cc[VREPRINT];
+       if (c != _POSIX_VDISABLE)
+               ttydisc_echo(tp, c, 0);
+       ttydisc_echo(tp, CNL, 0);
+       ttyinq_reprintpos_reset(&tp->t_inq);
+
+       ttyinq_line_iterate_from_linestart(&tp->t_inq, ttydisc_reprint_char, 
tp);
+}
+
+struct ttydisc_recalc_length {
+       struct tty *tp;
+       unsigned int curlen;
+};
+
+static void
+ttydisc_recalc_charlength(void *d, char c, int quote)
+{
+       struct ttydisc_recalc_length *data = d;
+       struct tty *tp = data->tp;
+
+       if (CTL_PRINT(c, quote)) {
+               if (CMP_FLAG(l, ECHOCTL))
+                       data->curlen += 2;
+       } else if (c == CTAB) {
+               data->curlen += 8 - (data->curlen & 7);
+       } else {
+               data->curlen++;
+       }
+}
+
+static unsigned int
+ttydisc_recalc_linelength(struct tty *tp)
+{
+       struct ttydisc_recalc_length data = { tp, tp->t_writepos };
+
+       ttyinq_line_iterate_from_reprintpos(&tp->t_inq,
+           ttydisc_recalc_charlength, &data);
+       return (data.curlen);
+}
+
+static int
+ttydisc_rubchar(struct tty *tp)
+{
+       char c;
+       int quote;
+       unsigned int prevpos, tablen;
+
+       if (ttyinq_peekchar(&tp->t_inq, &c, &quote) != 0)
+               return (-1);
+       ttyinq_unputchar(&tp->t_inq);
+
+       if (CMP_FLAG(l, ECHO)) {
+               /*
+                * Remove the character from the screen. This is even
+                * safe for characters that span multiple characters
+                * (tabs, quoted, etc).
+                */
+               if (tp->t_writepos >= tp->t_column) {
+                       /* Retype the sentence. */
+                       ttydisc_reprint(tp);
+               } else if (CMP_FLAG(l, ECHOE)) {
+                       if (CTL_PRINT(c, quote)) {
+                               /* Remove ^X formatted chars. */
+                               if (CMP_FLAG(l, ECHOCTL)) {
+                                       tp->t_column -= 2;
+                                       ttyoutq_write_nofrag(&tp->t_outq,
+                                           "\b\b  \b\b", 6);
+                               }
+                       } else if (c == ' ') {
+                               /* Space character needs no rubbing. */
+                               tp->t_column -= 1;
+                               ttyoutq_write_nofrag(&tp->t_outq, "\b", 1);
+                       } else if (c == CTAB) {
+                               /*
+                                * Making backspace work with tabs is
+                                * quite hard. Recalculate the length of
+                                * this character and remove it.
+                                *
+                                * Because terminal settings could be
+                                * changed while the line is being
+                                * inserted, the calculations don't have
+                                * to be correct. Make sure we keep the
+                                * tab length within proper bounds.
+                                */
+                               prevpos = ttydisc_recalc_linelength(tp);
+                               if (prevpos >= tp->t_column)
+                                       tablen = 1;
+                               else
+                                       tablen = tp->t_column - prevpos;
+                               if (tablen > 8)
+                                       tablen = 8;
+
+                               tp->t_column = prevpos;
+                               ttyoutq_write_nofrag(&tp->t_outq,
+                                   "\b\b\b\b\b\b\b\b", tablen);
+                               return (0);
+                       } else {
+                               /*
+                                * Remove a regular character by
+                                * punching a space over it.
+                                */
+                               tp->t_column -= 1;
+                               ttyoutq_write_nofrag(&tp->t_outq, "\b \b", 3);
+                       }
+               } else {
+                       /* Don't print spaces. */
+                       ttydisc_echo(tp, tp->t_termios.c_cc[VERASE], 0);
+               }
+       }
+
+       return (0);
+}
+
+static void
+ttydisc_rubword(struct tty *tp)
+{
+       char c;
+       int quote, alnum;
+
+       /* Strip whitespace first. */
+       for (;;) {
+               if (ttyinq_peekchar(&tp->t_inq, &c, &quote) != 0)
+                       return;
+               if (!CTL_WHITE(c))
+                       break;
+               ttydisc_rubchar(tp);
+       }
+
+       /*
+        * Record whether the last character from the previous iteration
+        * was alphanumeric or not. We need this to implement ALTWERASE.
+        */
+       alnum = CTL_ALNUM(c);
+       for (;;) {
+               ttydisc_rubchar(tp);
+
+               if (ttyinq_peekchar(&tp->t_inq, &c, &quote) != 0)
+                       return;
+               if (CTL_WHITE(c))
+                       return;
+               if (CMP_FLAG(l, ALTWERASE) && CTL_ALNUM(c) != alnum)
+                       return;
+       }
+}
+
+int
+ttydisc_rint(struct tty *tp, char c, int flags)
+{
+       int signal, quote = 0;
+       char ob[3] = { 0xff, 0x00 };
+       size_t ol;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       atomic_add_long(&tty_nin, 1);
+
+       if (ttyhook_hashook(tp, rint))
+               return ttyhook_rint(tp, c, flags);
+
+       if (tp->t_flags & TF_BYPASS)
+               goto processed;
+
+       if (flags) {
+               if (flags & TRE_BREAK) {
+                       if (CMP_FLAG(i, IGNBRK)) {
+                               /* Ignore break characters. */
+                               return (0);
+                       } else if (CMP_FLAG(i, BRKINT)) {
+                               /* Generate SIGINT on break. */
+                               tty_flush(tp, FREAD|FWRITE);
+                               tty_signal_pgrp(tp, SIGINT);
+                               return (0);
+                       } else {
+                               /* Just print it. */
+                               goto parmrk;
+                       }
+               } else if (flags & TRE_FRAMING ||
+                   (flags & TRE_PARITY && CMP_FLAG(i, INPCK))) {
+                       if (CMP_FLAG(i, IGNPAR)) {
+                               /* Ignore bad characters. */
+                               return (0);
+                       } else {
+                               /* Just print it. */
+                               goto parmrk;
+                       }
+               }
+       }
+
+       /* Allow any character to perform a wakeup. */
+       if (CMP_FLAG(i, IXANY))
+               tp->t_flags &= ~TF_STOPPED;
+
+       /* Remove the top bit. */
+       if (CMP_FLAG(i, ISTRIP))
+               c &= ~0x80;
+
+       /* Skip input processing when we want to print it literally. */
+       if (tp->t_flags & TF_LITERAL) {
+               tp->t_flags &= ~TF_LITERAL;
+               quote = 1;
+               goto processed;
+       }
+
+       /* Special control characters that are implementation dependent. */
+       if (CMP_FLAG(l, IEXTEN)) {
+               /* Accept the next character as literal. */
+               if (CMP_CC(VLNEXT, c)) {
+                       if (CMP_FLAG(l, ECHO)) {
+                               if (CMP_FLAG(l, ECHOE))
+                                       ttyoutq_write_nofrag(&tp->t_outq, 
"^\b", 2);
+                               else
+                                       ttydisc_echo(tp, c, 0);
+                       }
+                       tp->t_flags |= TF_LITERAL;
+                       return (0);
+               }
+       }
+
+       /*
+        * Handle signal processing.
+        */
+       if (CMP_FLAG(l, ISIG)) {
+               if (CMP_FLAG(l, ICANON|IEXTEN) == (ICANON|IEXTEN)) {
+                       if (CMP_CC(VSTATUS, c)) {
+                               tty_signal_pgrp(tp, SIGINFO);
+                               return (0);
+                       }
+               }
+
+               /*
+                * When compared to the old implementation, this
+                * implementation also flushes the output queue. POSIX
+                * is really brief about this, but does makes us assume
+                * we have to do so.
+                */
+               signal = 0;
+               if (CMP_CC(VINTR, c)) {
+                       signal = SIGINT;
+               } else if (CMP_CC(VQUIT, c)) {
+                       signal = SIGQUIT;
+               } else if (CMP_CC(VSUSP, c)) {
+                       signal = SIGTSTP;
+               }
+
+               if (signal != 0) {
+                       /*
+                        * Echo the character before signalling the
+                        * processes.
+                        */
+                       if (!CMP_FLAG(l, NOFLSH))
+                               tty_flush(tp, FREAD|FWRITE);
+                       ttydisc_echo(tp, c, 0);
+                       tty_signal_pgrp(tp, signal);
+                       return (0);
+               }
+       }
+
+       /*
+        * Handle start/stop characters.
+        */
+       if (CMP_FLAG(i, IXON)) {
+               if (CMP_CC(VSTOP, c)) {
+                       /* Stop it if we aren't stopped yet. */
+                       if ((tp->t_flags & TF_STOPPED) == 0) {
+                               tp->t_flags |= TF_STOPPED;
+                               return (0);
+                       }
+                       /*
+                        * Fallthrough:
+                        * When VSTART == VSTOP, we should make this key
+                        * toggle it.
+                        */
+                       if (!CMP_CC(VSTART, c))
+                               return (0);
+               }
+               if (CMP_CC(VSTART, c)) {
+                       tp->t_flags &= ~TF_STOPPED;
+                       return (0);
+               }
+       }
+
+       /* Conversion of CR and NL. */
+       switch (c) {
+       case CCR:
+               if (CMP_FLAG(i, IGNCR))
+                       return (0);
+               if (CMP_FLAG(i, ICRNL))
+                       c = CNL;
+               break;
+       case CNL:
+               if (CMP_FLAG(i, INLCR))
+                       c = CCR;
+               break;
+       }
+
+       /* Canonical line editing. */
+       if (CMP_FLAG(l, ICANON)) {
+               if (CMP_CC(VERASE, c) || CMP_CC(VERASE2, c)) {
+                       ttydisc_rubchar(tp);
+                       return (0);
+               } else if (CMP_CC(VKILL, c)) {
+                       while (ttydisc_rubchar(tp) == 0);
+                       return (0);
+               } else if (CMP_FLAG(l, IEXTEN)) {
+                       if (CMP_CC(VWERASE, c)) {
+                               ttydisc_rubword(tp);
+                               return (0);
+                       } else if (CMP_CC(VREPRINT, c)) {
+                               ttydisc_reprint(tp);
+                               return (0);
+                       }
+               }
+       }
+
+processed:
+       if (CMP_FLAG(i, PARMRK) && (unsigned char)c == 0xff) {
+               /* Print 0xff 0xff. */
+               ob[1] = 0xff;
+               ol = 2;
+               quote = 1;
+       } else {
+               ob[0] = c;
+               ol = 1;
+       }
+
+       goto print;
+
+parmrk:
+       if (CMP_FLAG(i, PARMRK)) {
+               /* Prepend 0xff 0x00 0x.. */
+               ob[2] = c;
+               ol = 3;
+               quote = 1;
+       } else {
+               ob[0] = c;
+               ol = 1;
+       }
+
+print:
+       /* See if we can store this on the input queue. */
+       if (ttyinq_write_nofrag(&tp->t_inq, ob, ol, quote) != 0) {
+               if (CMP_FLAG(i, IMAXBEL))
+                       ttyoutq_write_nofrag(&tp->t_outq, "\a", 1);
+
+               /*
+                * Prevent a deadlock here. It may be possible that a
+                * user has entered so much data, there is no data
+                * available to read(), but the buffers are full anyway.
+                *
+                * Only enter the high watermark if the device driver
+                * can actually transmit something.
+                */
+               if (ttyinq_bytescanonicalized(&tp->t_inq) == 0)
+                       return (0);
+
+               tty_hiwat_in_block(tp);
+               return (-1);
+       }
+
+       /*
+        * In raw mode, we canonicalize after receiving a single
+        * character. Otherwise, we canonicalize when we receive a
+        * newline, VEOL or VEOF, but only when it isn't quoted.
+        */
+       if (!CMP_FLAG(l, ICANON) ||
+           (!quote && (c == CNL || CMP_CC(VEOL, c) || CMP_CC(VEOF, c)))) {
+               ttyinq_canonicalize(&tp->t_inq);
+       }
+
+       ttydisc_echo(tp, c, quote);
+
+       return (0);
+}
+
+size_t
+ttydisc_rint_simple(struct tty *tp, const void *buf, size_t len)
+{
+       const char *cbuf;
+
+       if (ttydisc_can_bypass(tp))
+               return (ttydisc_rint_bypass(tp, buf, len));
+
+       for (cbuf = buf; len-- > 0; cbuf++) {
+               if (ttydisc_rint(tp, *cbuf, 0) != 0)
+                       break;
+       }
+
+       return (cbuf - (const char *)buf);
+}
+
+size_t
+ttydisc_rint_bypass(struct tty *tp, const void *buf, size_t len)
+{
+       size_t ret;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       MPASS(tp->t_flags & TF_BYPASS);
+
+       atomic_add_long(&tty_nin, len);
+
+       if (ttyhook_hashook(tp, rint_bypass))
+               return ttyhook_rint_bypass(tp, buf, len);
+
+       ret = ttyinq_write(&tp->t_inq, buf, len, 0);
+       ttyinq_canonicalize(&tp->t_inq);
+       if (ret < len)
+               tty_hiwat_in_block(tp);
+
+       return (ret);
+}
+
+void
+ttydisc_rint_done(struct tty *tp)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (ttyhook_hashook(tp, rint_done))
+               ttyhook_rint_done(tp);
+
+       /* Wake up readers. */
+       tty_wakeup(tp, FREAD);
+       /* Wake up driver for echo. */
+       ttydevsw_outwakeup(tp);
+}
+
+size_t
+ttydisc_rint_poll(struct tty *tp)
+{
+       size_t l;
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (ttyhook_hashook(tp, rint_poll))
+               return ttyhook_rint_poll(tp);
+
+       /*
+        * XXX: Still allow character input when there's no space in the
+        * buffers, but we haven't entered the high watermark. This is
+        * to allow backspace characters to be inserted when in
+        * canonical mode.
+        */
+       l = ttyinq_bytesleft(&tp->t_inq);
+       if (l == 0 && (tp->t_flags & TF_HIWAT_IN) == 0)
+               return (1);
+
+       return (l);
+}
+
+static void
+ttydisc_wakeup_watermark(struct tty *tp)
+{
+       size_t c;
+
+       c = ttyoutq_bytesleft(&tp->t_outq);
+       if (tp->t_flags & TF_HIWAT_OUT) {
+               /* Only allow us to run when we're below the watermark. */
+               if (c < tp->t_outlow)
+                       return;
+
+               /* Reset the watermark. */
+               tp->t_flags &= ~TF_HIWAT_OUT;
+       } else {
+               /* Only run when we have data at all. */
+               if (c == 0)
+                       return;
+       }
+       tty_wakeup(tp, FWRITE);
+}
+
+size_t
+ttydisc_getc(struct tty *tp, void *buf, size_t len)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tp->t_flags & TF_STOPPED)
+               return (0);
+
+       if (ttyhook_hashook(tp, getc_inject))
+               return ttyhook_getc_inject(tp, buf, len);
+
+       len = ttyoutq_read(&tp->t_outq, buf, len);
+
+       if (ttyhook_hashook(tp, getc_capture))
+               ttyhook_getc_capture(tp, buf, len);
+
+       ttydisc_wakeup_watermark(tp);
+       atomic_add_long(&tty_nout, len);
+
+       return (len);
+}
+
+int
+ttydisc_getc_uio(struct tty *tp, struct uio *uio)
+{
+       int error = 0;
+       ssize_t obytes = uio->uio_resid;
+       size_t len;
+       char buf[TTY_STACKBUF];
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tp->t_flags & TF_STOPPED)
+               return (0);
+
+       /*
+        * When a TTY hook is attached, we cannot perform unbuffered
+        * copying to userspace. Just call ttydisc_getc() and
+        * temporarily store data in a shadow buffer.
+        */
+       if (ttyhook_hashook(tp, getc_capture) ||
+           ttyhook_hashook(tp, getc_inject)) {
+               while (uio->uio_resid > 0) {
+                       /* Read to shadow buffer. */
+                       len = ttydisc_getc(tp, buf,
+                           MIN(uio->uio_resid, sizeof buf));
+                       if (len == 0)
+                               break;
+
+                       /* Copy to userspace. */
+                       tty_unlock(tp);
+                       error = uiomove(buf, len, uio);
+                       tty_lock(tp);
+
+                       if (error != 0)
+                               break;
+               }
+       } else {
+               error = ttyoutq_read_uio(&tp->t_outq, tp, uio);
+
+               ttydisc_wakeup_watermark(tp);
+               atomic_add_long(&tty_nout, obytes - uio->uio_resid);
+       }
+
+       return (error);
+}
+
+size_t
+ttydisc_getc_poll(struct tty *tp)
+{
+
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tp->t_flags & TF_STOPPED)
+               return (0);
+
+       if (ttyhook_hashook(tp, getc_poll))
+               return ttyhook_getc_poll(tp);
+
+       return ttyoutq_bytesused(&tp->t_outq);
+}
+
+/*
+ * XXX: not really related to the TTYDISC, but we'd better put
+ * tty_putchar() here, because we need to perform proper output
+ * processing.
+ */
+
+int
+tty_putchar(struct tty *tp, char c)
+{
+       tty_lock_assert(tp, MA_OWNED);
+
+       if (tty_gone(tp))
+               return (-1);
+
+       ttydisc_echo_force(tp, c, 0);
+       tp->t_writepos = tp->t_column;
+       ttyinq_reprintpos_set(&tp->t_inq);
+
+       ttydevsw_outwakeup(tp);
+       return (0);
+}
diff --git a/freebsd/sys/sys/_termios.h b/freebsd/sys/sys/_termios.h
new file mode 100644
index 0000000..3fb5bf4
--- /dev/null
+++ b/freebsd/sys/sys/_termios.h
@@ -0,0 +1,222 @@
+/*-
+ * Copyright (c) 1988, 1989, 1993, 1994
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     @(#)termios.h   8.3 (Berkeley) 3/28/94
+ * $FreeBSD$
+ */
+
+#ifndef _SYS__TERMIOS_H_
+#define        _SYS__TERMIOS_H_
+
+/*
+ * Special Control Characters
+ *
+ * Index into c_cc[] character array.
+ *
+ *     Name         Subscript  Enabled by
+ */
+#define        VEOF            0       /* ICANON */
+#define        VEOL            1       /* ICANON */
+#ifndef _POSIX_SOURCE
+#define        VEOL2           2       /* ICANON together with IEXTEN */
+#endif
+#define        VERASE          3       /* ICANON */
+#ifndef _POSIX_SOURCE
+#define        VWERASE         4       /* ICANON together with IEXTEN */
+#endif
+#define        VKILL           5       /* ICANON */
+#ifndef _POSIX_SOURCE
+#define        VREPRINT        6       /* ICANON together with IEXTEN */
+#define        VERASE2         7       /* ICANON */
+#endif
+/*                     7          ex-spare 1 */
+#define        VINTR           8       /* ISIG */
+#define        VQUIT           9       /* ISIG */
+#define        VSUSP           10      /* ISIG */
+#ifndef _POSIX_SOURCE
+#define        VDSUSP          11      /* ISIG together with IEXTEN */
+#endif
+#define        VSTART          12      /* IXON, IXOFF */
+#define        VSTOP           13      /* IXON, IXOFF */
+#ifndef _POSIX_SOURCE
+#define        VLNEXT          14      /* IEXTEN */
+#define        VDISCARD        15      /* IEXTEN */
+#endif
+#define        VMIN            16      /* !ICANON */
+#define        VTIME           17      /* !ICANON */
+#ifndef _POSIX_SOURCE
+#define        VSTATUS         18      /* ICANON together with IEXTEN */
+/*                     19         spare 2 */
+#endif
+#define        NCCS            20
+
+#define        _POSIX_VDISABLE 0xff
+
+/*
+ * Input flags - software input processing
+ */
+#define        IGNBRK          0x00000001      /* ignore BREAK condition */
+#define        BRKINT          0x00000002      /* map BREAK to SIGINTR */
+#define        IGNPAR          0x00000004      /* ignore (discard) parity 
errors */
+#define        PARMRK          0x00000008      /* mark parity and framing 
errors */
+#define        INPCK           0x00000010      /* enable checking of parity 
errors */
+#define        ISTRIP          0x00000020      /* strip 8th bit off chars */
+#define        INLCR           0x00000040      /* map NL into CR */
+#define        IGNCR           0x00000080      /* ignore CR */
+#define        ICRNL           0x00000100      /* map CR to NL (ala CRMOD) */
+#define        IXON            0x00000200      /* enable output flow control */
+#define        IXOFF           0x00000400      /* enable input flow control */
+#ifndef _POSIX_SOURCE
+#define        IXANY           0x00000800      /* any char will restart after 
stop */
+#define        IMAXBEL         0x00002000      /* ring bell on input queue 
full */
+#endif  /*_POSIX_SOURCE */
+
+/*
+ * Output flags - software output processing
+ */
+#define        OPOST           0x00000001      /* enable following output 
processing */
+#ifndef _POSIX_SOURCE
+#define        ONLCR           0x00000002      /* map NL to CR-NL (ala CRMOD) 
*/
+#define        TABDLY          0x00000004      /* tab delay mask */
+#define            TAB0            0x00000000      /* no tab delay and 
expansion */
+#define            TAB3            0x00000004      /* expand tabs to spaces */
+#define        ONOEOT          0x00000008      /* discard EOT's (^D) on 
output) */
+#define        OCRNL           0x00000010      /* map CR to NL on output */
+#define        ONOCR           0x00000020      /* no CR output at column 0 */
+#define        ONLRET          0x00000040      /* NL performs CR function */
+#endif  /*_POSIX_SOURCE */
+
+/*
+ * Control flags - hardware control of terminal
+ */
+#ifndef _POSIX_SOURCE
+#define        CIGNORE         0x00000001      /* ignore control flags */
+#endif
+#define        CSIZE           0x00000300      /* character size mask */
+#define            CS5             0x00000000      /* 5 bits (pseudo) */
+#define            CS6             0x00000100      /* 6 bits */
+#define            CS7             0x00000200      /* 7 bits */
+#define            CS8             0x00000300      /* 8 bits */
+#define        CSTOPB          0x00000400      /* send 2 stop bits */
+#define        CREAD           0x00000800      /* enable receiver */
+#define        PARENB          0x00001000      /* parity enable */
+#define        PARODD          0x00002000      /* odd parity, else even */
+#define        HUPCL           0x00004000      /* hang up on last close */
+#define        CLOCAL          0x00008000      /* ignore modem status lines */
+#ifndef _POSIX_SOURCE
+#define        CCTS_OFLOW      0x00010000      /* CTS flow control of output */
+#define        CRTSCTS         (CCTS_OFLOW | CRTS_IFLOW)
+#define        CRTS_IFLOW      0x00020000      /* RTS flow control of input */
+#define        CDTR_IFLOW      0x00040000      /* DTR flow control of input */
+#define        CDSR_OFLOW      0x00080000      /* DSR flow control of output */
+#define        CCAR_OFLOW      0x00100000      /* DCD flow control of output */
+#endif
+
+
+/*
+ * "Local" flags - dumping ground for other state
+ *
+ * Warning: some flags in this structure begin with
+ * the letter "I" and look like they belong in the
+ * input flag.
+ */
+
+#ifndef _POSIX_SOURCE
+#define        ECHOKE          0x00000001      /* visual erase for line kill */
+#endif  /*_POSIX_SOURCE */
+#define        ECHOE           0x00000002      /* visually erase chars */
+#define        ECHOK           0x00000004      /* echo NL after line kill */
+#define        ECHO            0x00000008      /* enable echoing */
+#define        ECHONL          0x00000010      /* echo NL even if ECHO is off 
*/
+#ifndef _POSIX_SOURCE
+#define        ECHOPRT         0x00000020      /* visual erase mode for 
hardcopy */
+#define        ECHOCTL         0x00000040      /* echo control chars as 
^(Char) */
+#endif  /*_POSIX_SOURCE */
+#define        ISIG            0x00000080      /* enable signals INTR, QUIT, 
[D]SUSP */
+#define        ICANON          0x00000100      /* canonicalize input lines */
+#ifndef _POSIX_SOURCE
+#define        ALTWERASE       0x00000200      /* use alternate WERASE 
algorithm */
+#endif  /*_POSIX_SOURCE */
+#define        IEXTEN          0x00000400      /* enable DISCARD and LNEXT */
+#define        EXTPROC         0x00000800      /* external processing */
+#define        TOSTOP          0x00400000      /* stop background jobs from 
output */
+#ifndef _POSIX_SOURCE
+#define        FLUSHO          0x00800000      /* output being flushed (state) 
*/
+#define        NOKERNINFO      0x02000000      /* no kernel output from 
VSTATUS */
+#define        PENDIN          0x20000000      /* XXX retype pending input 
(state) */
+#endif  /*_POSIX_SOURCE */
+#define        NOFLSH          0x80000000      /* don't flush after interrupt 
*/
+
+/*
+ * Standard speeds
+ */
+#define        B0      0
+#define        B50     50
+#define        B75     75
+#define        B110    110
+#define        B134    134
+#define        B150    150
+#define        B200    200
+#define        B300    300
+#define        B600    600
+#define        B1200   1200
+#define        B1800   1800
+#define        B2400   2400
+#define        B4800   4800
+#define        B9600   9600
+#define        B19200  19200
+#define        B38400  38400
+#ifndef _POSIX_SOURCE
+#define        B7200   7200
+#define        B14400  14400
+#define        B28800  28800
+#define        B57600  57600
+#define        B76800  76800
+#define        B115200 115200
+#define        B230400 230400
+#define        B460800 460800
+#define        B921600 921600
+#define        EXTA    19200
+#define        EXTB    38400
+#endif  /* !_POSIX_SOURCE */
+
+typedef unsigned int   tcflag_t;
+typedef unsigned char  cc_t;
+typedef unsigned int   speed_t;
+
+struct termios {
+       tcflag_t        c_iflag;        /* input flags */
+       tcflag_t        c_oflag;        /* output flags */
+       tcflag_t        c_cflag;        /* control flags */
+       tcflag_t        c_lflag;        /* local flags */
+       cc_t            c_cc[NCCS];     /* control chars */
+       speed_t         c_ispeed;       /* input speed */
+       speed_t         c_ospeed;       /* output speed */
+};
+
+#endif /* !_SYS__TERMIOS_H_ */
diff --git a/freebsd/sys/sys/cons.h b/freebsd/sys/sys/cons.h
new file mode 100644
index 0000000..0085daa
--- /dev/null
+++ b/freebsd/sys/sys/cons.h
@@ -0,0 +1,144 @@
+/*-
+ * Copyright (c) 1988 University of Utah.
+ * Copyright (c) 1991 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * the Systems Programming Group of the University of Utah Computer
+ * Science Department.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     from: @(#)cons.h        7.2 (Berkeley) 5/9/91
+ * $FreeBSD$
+ */
+
+#ifndef _MACHINE_CONS_H_
+#define        _MACHINE_CONS_H_
+
+struct consdev;
+struct tty;
+
+typedef        void    cn_probe_t(struct consdev *);
+typedef        void    cn_init_t(struct consdev *);
+typedef        void    cn_term_t(struct consdev *);
+typedef        void    cn_grab_t(struct consdev *);
+typedef        void    cn_ungrab_t(struct consdev *);
+typedef        int     cn_getc_t(struct consdev *);
+typedef        void    cn_putc_t(struct consdev *, int);
+
+struct consdev_ops {
+       cn_probe_t      *cn_probe;
+                               /* probe hardware and fill in consdev info */
+       cn_init_t       *cn_init;
+                               /* turn on as console */
+       cn_term_t       *cn_term;
+                               /* turn off as console */
+       cn_getc_t       *cn_getc;
+                               /* kernel getchar interface */
+       cn_putc_t       *cn_putc;
+                               /* kernel putchar interface */
+       cn_grab_t       *cn_grab;
+                               /* grab console for exclusive kernel use */
+       cn_ungrab_t     *cn_ungrab;
+                               /* ungrab console */
+};
+
+struct consdev {
+       const struct consdev_ops *cn_ops;
+                               /* console device operations. */
+       short   cn_pri;         /* pecking order; the higher the better */
+       void    *cn_arg;        /* drivers method argument */
+       int     cn_flags;       /* capabilities of this console */
+       char    cn_name[SPECNAMELEN + 1];       /* console (device) name */
+};
+
+/* values for cn_pri - reflect our policy for console selection */
+#define        CN_DEAD         0       /* device doesn't exist */
+#define CN_LOW         1       /* device is a last restort only */
+#define CN_NORMAL      2       /* device exists but is nothing special */
+#define CN_INTERNAL    3       /* "internal" bit-mapped display */
+#define CN_REMOTE      4       /* serial interface with remote bit set */
+
+/* Values for cn_flags. */
+#define        CN_FLAG_NODEBUG 0x00000001      /* Not supported with debugger. 
*/
+#define        CN_FLAG_NOAVAIL 0x00000002      /* Temporarily not available. */
+
+/* Visibility of characters in cngets() */
+#define        GETS_NOECHO     0       /* Disable echoing of characters. */
+#define        GETS_ECHO       1       /* Enable echoing of characters. */
+#define        GETS_ECHOPASS   2       /* Print a * for every character. */
+
+#ifdef _KERNEL
+
+extern struct msgbuf consmsgbuf; /* Message buffer for constty. */
+extern struct tty *constty;    /* Temporary virtual console. */
+
+#define        CONSOLE_DEVICE(name, ops, arg)                                  
\
+       static struct consdev name = {                                  \
+               .cn_ops = &ops,                                         \
+               .cn_arg = (arg),                                        \
+       };                                                              \
+       DATA_SET(cons_set, name)
+
+#define        CONSOLE_DRIVER(name)                                            
\
+       static const struct consdev_ops name##_consdev_ops = {          \
+               .cn_probe = name##_cnprobe,                             \
+               .cn_init = name##_cninit,                               \
+               .cn_term = name##_cnterm,                               \
+               .cn_getc = name##_cngetc,                               \
+               .cn_putc = name##_cnputc,                               \
+               .cn_grab = name##_cngrab,                               \
+               .cn_ungrab = name##_cnungrab,                           \
+       };                                                              \
+       CONSOLE_DEVICE(name##_consdev, name##_consdev_ops, NULL)
+
+/* Other kernel entry points. */
+void   cninit(void);
+void   cninit_finish(void);
+int    cnadd(struct consdev *);
+void   cnavailable(struct consdev *, int);
+void   cnremove(struct consdev *);
+void   cnselect(struct consdev *);
+void   cngrab(void);
+void   cnungrab(void);
+int    cncheckc(void);
+int    cngetc(void);
+void   cngets(char *, size_t, int);
+void   cnputc(int);
+void   cnputs(char *);
+int    cnunavailable(void);
+void   constty_set(struct tty *tp);
+void   constty_clear(void);
+
+/* sc(4) / vt(4) coexistence shim */
+#define        VTY_SC 0x01
+#define        VTY_VT 0x02
+int    vty_enabled(unsigned int);
+void   vty_set_preferred(unsigned int);
+
+#endif /* _KERNEL */
+
+#endif /* !_MACHINE_CONS_H_ */
diff --git a/freebsd/sys/sys/serial.h b/freebsd/sys/sys/serial.h
new file mode 100644
index 0000000..1a149a9
--- /dev/null
+++ b/freebsd/sys/sys/serial.h
@@ -0,0 +1,92 @@
+/*-
+ * Copyright (c) 2004 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file contains definitions which pertain to serial ports as such,
+ * (both async and sync), but which do not necessarily have anything to
+ * do with tty processing.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_SERIAL_H_
+#define        _SYS_SERIAL_H_
+
+
+/*
+ * Indentification of modem control signals.  These definitions match
+ * the TIOCMGET definitions in <sys/ttycom.h> shifted a bit down, and
+ * that identity is enforced with CTASSERT at the bottom of kern/tty.c
+ * Both the modem bits and delta bits must fit in 16 bit.
+ */
+#define        SER_DTR         0x0001          /* data terminal ready */
+#define        SER_RTS         0x0002          /* request to send */
+#define        SER_STX         0x0004          /* secondary transmit */
+#define        SER_SRX         0x0008          /* secondary receive */
+#define        SER_CTS         0x0010          /* clear to send */
+#define        SER_DCD         0x0020          /* data carrier detect */
+#define        SER_RI          0x0040          /* ring indicate */
+#define        SER_DSR         0x0080          /* data set ready */
+
+#define        SER_MASK_STATE  0x00ff
+
+/* Delta bits, used to indicate which signals should/was affected */
+#define        SER_DELTA(x)    ((x) << 8)
+
+#define        SER_DDTR        SER_DELTA(SER_DTR)
+#define        SER_DRTS        SER_DELTA(SER_RTS)
+#define        SER_DSTX        SER_DELTA(SER_STX)
+#define        SER_DSRX        SER_DELTA(SER_SRX)
+#define        SER_DCTS        SER_DELTA(SER_CTS)
+#define        SER_DDCD        SER_DELTA(SER_DCD)
+#define        SER_DRI         SER_DELTA(SER_RI)
+#define        SER_DDSR        SER_DELTA(SER_DSR)
+
+#define        SER_MASK_DELTA  SER_DELTA(SER_MASK_STATE)
+
+#ifdef _KERNEL
+/*
+ * Specification of interrupt sources typical for serial ports. These are
+ * useful when some umbrella driver like scc(4) has enough knowledge of
+ * the hardware to obtain the set of pending interrupts but does not itself
+ * handle the interrupt. Each interrupt source can be given an interrupt
+ * resource for which inferior drivers can install handlers. The lower 16
+ * bits are kept free for the signals above.
+ */
+#define        SER_INT_OVERRUN 0x010000
+#define        SER_INT_BREAK   0x020000
+#define        SER_INT_RXREADY 0x040000
+#define        SER_INT_SIGCHG  0x080000
+#define        SER_INT_TXIDLE  0x100000
+
+#define        SER_INT_MASK    0xff0000
+#define        SER_INT_SIGMASK (SER_MASK_DELTA | SER_MASK_STATE)
+
+#ifndef LOCORE
+typedef int serdev_intr_t(void*);
+#endif
+
+#endif /* _KERNEL */
+
+#endif /* !_SYS_SERIAL_H_ */
diff --git a/freebsd/sys/sys/timepps.h b/freebsd/sys/sys/timepps.h
new file mode 100644
index 0000000..d472c80
--- /dev/null
+++ b/freebsd/sys/sys/timepps.h
@@ -0,0 +1,266 @@
+/*-
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <p...@freebsd.org> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2011 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Julien Ridoux at the University
+ * of Melbourne under sponsorship from the FreeBSD Foundation.
+ *
+ * $FreeBSD$
+ *
+ * The is a FreeBSD version of the RFC 2783 API for Pulse Per Second 
+ * timing interfaces.  
+ */
+
+#ifndef _SYS_TIMEPPS_H_
+#define _SYS_TIMEPPS_H_
+
+#include <sys/_ffcounter.h>
+#include <sys/ioccom.h>
+#include <sys/time.h>
+
+#define PPS_API_VERS_1 1
+
+typedef int pps_handle_t;      
+
+typedef unsigned pps_seq_t;
+
+typedef struct ntp_fp {
+       unsigned int    integral;
+       unsigned int    fractional;
+} ntp_fp_t;
+
+typedef union pps_timeu {
+       struct timespec tspec;
+       ntp_fp_t        ntpfp;
+       unsigned long   longpad[3];
+} pps_timeu_t;
+
+typedef struct {
+       pps_seq_t       assert_sequence;        /* assert event seq # */
+       pps_seq_t       clear_sequence;         /* clear event seq # */
+       pps_timeu_t     assert_tu;
+       pps_timeu_t     clear_tu;
+       int             current_mode;           /* current mode bits */
+} pps_info_t;
+
+typedef struct {
+       pps_seq_t       assert_sequence;        /* assert event seq # */
+       pps_seq_t       clear_sequence;         /* clear event seq # */
+       pps_timeu_t     assert_tu;
+       pps_timeu_t     clear_tu;
+       ffcounter       assert_ffcount;         /* ffcounter on assert event */
+       ffcounter       clear_ffcount;          /* ffcounter on clear event */
+       int             current_mode;           /* current mode bits */
+} pps_info_ffc_t;
+
+#define assert_timestamp        assert_tu.tspec
+#define clear_timestamp         clear_tu.tspec
+
+#define assert_timestamp_ntpfp  assert_tu.ntpfp
+#define clear_timestamp_ntpfp   clear_tu.ntpfp
+
+typedef struct {
+       int api_version;                        /* API version # */
+       int mode;                               /* mode bits */
+       pps_timeu_t assert_off_tu;
+       pps_timeu_t clear_off_tu;
+} pps_params_t;
+
+#define assert_offset   assert_off_tu.tspec
+#define clear_offset    clear_off_tu.tspec
+
+#define assert_offset_ntpfp     assert_off_tu.ntpfp
+#define clear_offset_ntpfp      clear_off_tu.ntpfp
+
+
+#define PPS_CAPTUREASSERT      0x01
+#define PPS_CAPTURECLEAR       0x02
+#define PPS_CAPTUREBOTH                0x03
+
+#define PPS_OFFSETASSERT       0x10
+#define PPS_OFFSETCLEAR                0x20
+
+#define PPS_ECHOASSERT         0x40
+#define PPS_ECHOCLEAR          0x80
+
+#define PPS_CANWAIT            0x100
+#define PPS_CANPOLL            0x200
+
+#define PPS_TSFMT_TSPEC                0x1000
+#define PPS_TSFMT_NTPFP                0x2000
+
+#define        PPS_TSCLK_FBCK          0x10000
+#define        PPS_TSCLK_FFWD          0x20000
+#define        PPS_TSCLK_MASK          0x30000
+
+#define PPS_KC_HARDPPS         0
+#define PPS_KC_HARDPPS_PLL     1
+#define PPS_KC_HARDPPS_FLL     2
+
+struct pps_fetch_args {
+       int tsformat;
+       pps_info_t      pps_info_buf;
+       struct timespec timeout;
+};
+
+struct pps_fetch_ffc_args {
+       int             tsformat;
+       pps_info_ffc_t  pps_info_buf_ffc;
+       struct timespec timeout;
+};
+
+struct pps_kcbind_args {
+       int kernel_consumer;
+       int edge;
+       int tsformat;
+};
+
+#define PPS_IOC_CREATE         _IO('1', 1)
+#define PPS_IOC_DESTROY                _IO('1', 2)
+#define PPS_IOC_SETPARAMS      _IOW('1', 3, pps_params_t)
+#define PPS_IOC_GETPARAMS      _IOR('1', 4, pps_params_t)
+#define PPS_IOC_GETCAP         _IOR('1', 5, int)
+#define PPS_IOC_FETCH          _IOWR('1', 6, struct pps_fetch_args)
+#define PPS_IOC_KCBIND         _IOW('1', 7, struct pps_kcbind_args)
+#define        PPS_IOC_FETCH_FFCOUNTER _IOWR('1', 8, struct pps_fetch_ffc_args)
+
+#ifdef _KERNEL
+
+struct mtx;
+
+#define        KCMODE_EDGEMASK         0x03
+#define        KCMODE_ABIFLAG          0x80000000 /* Internal use: abi-aware 
driver. */
+
+#define        PPS_ABI_VERSION         1
+
+#define        PPSFLAG_MTX_SPIN        0x01    /* Driver mtx is MTX_SPIN type. 
*/
+
+struct pps_state {
+       /* Capture information. */
+       struct timehands *capth;
+       struct fftimehands *capffth;
+       unsigned        capgen;
+       unsigned        capcount;
+
+       /* State information. */
+       pps_params_t    ppsparam;
+       pps_info_t      ppsinfo;
+       pps_info_ffc_t  ppsinfo_ffc;
+       int             kcmode;
+       int             ppscap;
+       struct timecounter *ppstc;
+       unsigned        ppscount[3];
+       /*
+        * The following fields are valid if the driver calls pps_init_abi().
+        */
+       uint16_t        driver_abi;     /* Driver sets before pps_init_abi(). */
+       uint16_t        kernel_abi;     /* Kernel sets during pps_init_abi(). */
+       struct mtx      *driver_mtx;    /* Optional, valid if non-NULL. */
+       uint32_t        flags;
+};
+
+void pps_capture(struct pps_state *pps);
+void pps_event(struct pps_state *pps, int event);
+void pps_init(struct pps_state *pps);
+void pps_init_abi(struct pps_state *pps);
+int pps_ioctl(unsigned long cmd, caddr_t data, struct pps_state *pps);
+void hardpps(struct timespec *tsp, long nsec);
+
+#else /* !_KERNEL */
+
+static __inline int
+time_pps_create(int filedes, pps_handle_t *handle)
+{
+       int error;
+
+       *handle = -1;
+       error = ioctl(filedes, PPS_IOC_CREATE, 0);
+       if (error < 0) 
+               return (-1);
+       *handle = filedes;
+       return (0);
+}
+
+static __inline int
+time_pps_destroy(pps_handle_t handle)
+{
+       return (ioctl(handle, PPS_IOC_DESTROY, 0));
+}
+
+static __inline int
+time_pps_setparams(pps_handle_t handle, const pps_params_t *ppsparams)
+{
+       return (ioctl(handle, PPS_IOC_SETPARAMS, ppsparams));
+}
+
+static __inline int
+time_pps_getparams(pps_handle_t handle, pps_params_t *ppsparams)
+{
+       return (ioctl(handle, PPS_IOC_GETPARAMS, ppsparams));
+}
+
+static __inline int 
+time_pps_getcap(pps_handle_t handle, int *mode)
+{
+       return (ioctl(handle, PPS_IOC_GETCAP, mode));
+}
+
+static __inline int
+time_pps_fetch(pps_handle_t handle, const int tsformat,
+       pps_info_t *ppsinfobuf, const struct timespec *timeout)
+{
+       int error;
+       struct pps_fetch_args arg;
+
+       arg.tsformat = tsformat;
+       if (timeout == NULL) {
+               arg.timeout.tv_sec = -1;
+               arg.timeout.tv_nsec = -1;
+       } else
+               arg.timeout = *timeout;
+       error = ioctl(handle, PPS_IOC_FETCH, &arg);
+       *ppsinfobuf = arg.pps_info_buf;
+       return (error);
+}
+
+static __inline int
+time_pps_fetch_ffc(pps_handle_t handle, const int tsformat,
+       pps_info_ffc_t *ppsinfobuf, const struct timespec *timeout)
+{
+       struct pps_fetch_ffc_args arg;
+       int error;
+
+       arg.tsformat = tsformat;
+       if (timeout == NULL) {
+               arg.timeout.tv_sec = -1;
+               arg.timeout.tv_nsec = -1;
+       } else {
+               arg.timeout = *timeout;
+       }
+       error = ioctl(handle, PPS_IOC_FETCH_FFCOUNTER, &arg);
+       *ppsinfobuf = arg.pps_info_buf_ffc;
+       return (error);
+}
+
+static __inline int
+time_pps_kcbind(pps_handle_t handle, const int kernel_consumer,
+       const int edge, const int tsformat)
+{
+       struct pps_kcbind_args arg;
+
+       arg.kernel_consumer = kernel_consumer;
+       arg.edge = edge;
+       arg.tsformat = tsformat;
+       return (ioctl(handle, PPS_IOC_KCBIND, &arg));
+}
+
+#endif /* KERNEL */
+
+#endif /* !_SYS_TIMEPPS_H_ */
diff --git a/freebsd/sys/sys/ttydefaults.h b/freebsd/sys/sys/ttydefaults.h
new file mode 100644
index 0000000..82929f9
--- /dev/null
+++ b/freebsd/sys/sys/ttydefaults.h
@@ -0,0 +1,111 @@
+/*-
+ * Copyright (c) 1982, 1986, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *     @(#)ttydefaults.h       8.4 (Berkeley) 1/21/94
+ * $FreeBSD$
+ */
+
+/*
+ * System wide defaults for terminal state.
+ */
+#ifndef _SYS_TTYDEFAULTS_H_
+#define        _SYS_TTYDEFAULTS_H_
+
+/*
+ * Defaults on "first" open.
+ */
+#define        TTYDEF_IFLAG    (BRKINT | ICRNL | IMAXBEL | IXON | IXANY)
+#define        TTYDEF_OFLAG    (OPOST | ONLCR)
+#define        TTYDEF_LFLAG_NOECHO (ICANON | ISIG | IEXTEN)
+#define        TTYDEF_LFLAG_ECHO (TTYDEF_LFLAG_NOECHO \
+       | ECHO | ECHOE | ECHOKE | ECHOCTL)
+#define        TTYDEF_LFLAG TTYDEF_LFLAG_ECHO
+#define        TTYDEF_CFLAG    (CREAD | CS8 | HUPCL)
+#define        TTYDEF_SPEED    (B9600)
+
+/*
+ * Control Character Defaults
+ */
+/*
+ * XXX: A lot of code uses lowercase characters, but control-character
+ * conversion is actually only valid when applied to uppercase
+ * characters. We just treat lowercase characters as if they were
+ * inserted as uppercase.
+ */
+#define        CTRL(x) ((x) >= 'a' && (x) <= 'z' ? \
+       ((x) - 'a' + 1) : (((x) - 'A' + 1) & 0x7f))
+#define        CEOF            CTRL('D')
+#define        CEOL            0xff            /* XXX avoid _POSIX_VDISABLE */
+#define        CERASE          CTRL('?')
+#define        CERASE2         CTRL('H')
+#define        CINTR           CTRL('C')
+#define        CSTATUS         CTRL('T')
+#define        CKILL           CTRL('U')
+#define        CMIN            1
+#define        CQUIT           CTRL('\\')
+#define        CSUSP           CTRL('Z')
+#define        CTIME           0
+#define        CDSUSP          CTRL('Y')
+#define        CSTART          CTRL('Q')
+#define        CSTOP           CTRL('S')
+#define        CLNEXT          CTRL('V')
+#define        CDISCARD        CTRL('O')
+#define        CWERASE         CTRL('W')
+#define        CREPRINT        CTRL('R')
+#define        CEOT            CEOF
+/* compat */
+#define        CBRK            CEOL
+#define        CRPRNT          CREPRINT
+#define        CFLUSH          CDISCARD
+
+/* PROTECTED INCLUSION ENDS HERE */
+#endif /* !_SYS_TTYDEFAULTS_H_ */
+
+/*
+ * #define TTYDEFCHARS to include an array of default control characters.
+ */
+#ifdef TTYDEFCHARS
+
+#include <sys/cdefs.h>
+#include <sys/_termios.h>
+
+static const cc_t ttydefchars[] = {
+       CEOF, CEOL, CEOL, CERASE, CWERASE, CKILL, CREPRINT, CERASE2, CINTR,
+       CQUIT, CSUSP, CDSUSP, CSTART, CSTOP, CLNEXT, CDISCARD, CMIN, CTIME,
+       CSTATUS, _POSIX_VDISABLE
+};
+_Static_assert(sizeof(ttydefchars) / sizeof(cc_t) == NCCS,
+    "Size of ttydefchars does not match NCCS");
+
+#undef TTYDEFCHARS
+#endif /* TTYDEFCHARS */
-- 
1.9.1

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