how to call dumpsys() in kernel

[karu.pruun]

Hello

I am trying to get a dump since the kernel is crashing at boot. I
cannot call dumpsys at the db> prompt manually since keyboard is hung,
probably because it's a (internal) USB keyboard. So I figured out I'd
just call dumpsys() directly in sys/ddb/db_command.c, line 463, before
it gets hung at reading from keyboard at line 465.

However, that naive call does not work, dumpsys() probably needs more
parameters to be set. I put a few kprintfs(); into the dumpsys() in
sys/kern/kern_shutdown.c and see it enter there, but it never makes
into the if() loop (line 913 in sys/kern/kern_shutdown.c) and call
md_dumpsys() that does the actual dump.

Question: can anyone suggest how to call dumpsys() so I can get the
kernel dump to the swap partition? I have "dumpdev="ad4s1b"" in
/boot/loader.conf.

Thanks

Peeter

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