On Mon, 22 Aug 2022, Warner Losh wrote:
Hi,
On Mon, Aug 22, 2022 at 9:17 AM Konstantin Belousov <kostik...@gmail.com>
wrote:
On Mon, Aug 22, 2022 at 02:56:47PM +0000, Bjoern A. Zeeb wrote:
Hi,
I am trying to get some arm64 up and running a bit but cannot use
loader. I have an MD_ROOT embedded in the kernel with /rescue on it.
I set INIT_PATH=/rescue/sh .
However that doesn't seem to work:
start_init: trying /rescue/sh
init died (signal 0, exit 0)
panic: Going nowhere without my init!
Anyone any ideas?
Kernel does not set up the standard file descriptors for stdin/out/err
for init. When you try to directly exec /rescue/sh (or /bin/sh), it cannot
perform any io.
Agreed. init does lots of magic, in addition to setting up stdin/out/err
(like
deal with process groups, etc). /bin/sh doesn't do any of that magic, so it
can't possibly work as init (PID 1).
Your best bet is to boot -s (RB_SINGLE in the kernel boot_single=yes in the
boot loader). You'd think you'd be able to symbolically link /etc/rc to
/rescue/sh,
but that will result in sh trying to execute /rescue/sh as a shell script
and no good
can come from it. I've had luck with "echo sh > $DESTDIR/etc/rc;
chmod +x $DESTDIR/etc/rc" in the past, but I haven't tried that trick in
ages...
The simple equivalent to a tmp file does work.
/rescue/init was simply "hanging" on earlier boots which is why I
had initially switche dto sh.
Here's a few things I did overall:
- disable GDB in kernel config (it gave 2 lines of jitterish on
initial kernel printf lines before Copyrights.
- Added bootargs = FreeBSD:-vs to the chosen section in FDT
given I cannot have loader (no EFI); the guard trick is nice if you
know about it ;)
- Removed my previous env file I had added to the kernel to set
tunables.
- linked /bin/sh to /rescue/sh
- put a printf "hello world\n"; exit 1 in the top of /etc/rc just in
case -s wouldn't work
- changed INIT_PATH=/rescue/init
Got a sh and can run sysctl and dmesg and type echo * in /rescue :)
Even reboot works :)
Now that basic netbooting and user space work I can start adding SoC
drivers bit by bit over the next weeks/months :) That'll be a lot
more unfun.
Thanks you two! Along with help from Andy earlier this made my day!
Lots of joy!
/bz
--
Bjoern A. Zeeb r15:7
