On 14/07/2019 01:34, Joel Sherrill wrote:
On Sat, Jul 13, 2019 at 1:42 PM Chris Johns <chr...@rtems.org
<mailto:chr...@rtems.org>> wrote:
On 13/7/19 5:16 pm, Nils Hölscher wrote:
> Hi,
>
> After I made sure that my fdt is correct I wondered why the pruss
was still not
> accessible.
> When I researched more about userspace drivers in Linux I found
out, that I have
> overseen the pru UIO module in Linux.
> This is the part that links the PRUs to the /dev/uio[0-7].
> Which then would be used by the sources I currently use.
> The UIO source is available here:
> https://github.com/beagleboard/linux/blob/3.8/drivers/uio/uio_pruss.c
> However this requires the linux UIO lib to load the modules and
abstract the
> device into a file.
>
> While researching I also found that BSD has a PRU driver.
> Also this driver is more feature rich as it support PRU debugging.
> The sources can be found her:
> https://bitbucket.org/rpaulo/libpru/src/default/
> Additionally I found these sources in the FreeBSD tree:
>
https://github.com/freebsd/freebsd/blob/250e158ddf52459661439141407bca505d199c19/sys/arm/ti/ti_pruss.c
> This code also registers the PRUs in /dev/.
> On the other hand the BSD drivers have no documentation at all.
>
> These are the code lines that will fail without a file in /dev.
> Linux:
https://github.com/nilhoel1/rtems-pru/blob/master/ti/prussdrv.c#L265
> BSD:
https://bitbucket.org/rpaulo/libpru/src/5cb7271533a96d177e73492f7cc40fa4b28396a5/ti-pru.c#lines-614
>
> So my questions are:
> 1. How are drivers registered to /dev in RTEMS? (examples)
I suggest you look at cpukit/include/rtems/io.h and then for
examples of this
interface being used in the bsp directory.
There is a helper in the IO Manager which is implemented as a call to
mknod()
which is a standard call.
In libbsd devices should be added with IMFS_make_generic_node():
freebsd/sys/net/bpf.c: rv = IMFS_make_generic_node("/dev/bpf", mode,
&bpf_imfs_control, NULL);
freebsd/sys/kern/uipc_usrreq.c: rv = IMFS_make_generic_node(soun->sun_path,
rtemsbsd/sys/fs/devfs/devfs_devs.c: rv =
IMFS_make_generic_node(dev->si_path, mode, &devfs_imfs_control,
--
Sebastian Huber, embedded brains GmbH
Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone : +49 89 189 47 41-16
Fax : +49 89 189 47 41-09
E-Mail : sebastian.hu...@embedded-brains.de
PGP : Public key available on request.
Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
_______________________________________________
devel mailing list
devel@rtems.org
http://lists.rtems.org/mailman/listinfo/devel
