On 11/30/25 5:00 AM, Avon Robertson wrote:
My home router hangs while booting /bsd.sp at the following line:
root on sd0a (cd6f434607620efd.a) swap on sd0b dump on sd0b
The router does not hang while booting if:
boot hd0a:/bsd.sp -c
and then
disable amdgpu
is specified in UKC followed by
quit
However; as
$ cat /etc/bsd.re-config
disable amdgpu
has been as above for 10 weeks and during that time /bsd has booted
daily without errors occurring, my question is:
what am I misunderstanding in the bsd.re-config(5) description below?
DESCRIPTION
The bsd.re-config file contains kernel modification commands in
config(8) format. If present, it is used during system startup to
configure the kernel that will be running at the next boot. It can
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
be used to enable or disable specific devices in the kernel.
The router was sysupgrade'd -s this morning to:
OpenBSD 7.8-current (GENERIC.MP) #127: Sat Nov 29 10:44:59 MST 2025
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP
OpenBSD 7.8-current (GENERIC) #126: Sat Nov 29 10:32:29 MST 2025
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC
TIA for your input.
I do believe you understand the words a bit differently than intended.
Remember: OpenBSD relinks the kernel every boot. Sequence of events:
1) boot a kernel
2) kernel is running, multi-user, and in control of the hardware.
3) System startup takes place ... including
3a) daemons
3...)
3k) /bsd is relinked (KARL -- Kernel Address Randomization Link)
3...)
4) System is fully on-line and devoted to your tasks
5) ...time goes by, you do stuff...
6) you reboot
1) boot a kernel (relinked in step 3a above)
Now read the description again...
"If present, it is used during system startup [step 3!!] to configure the
kernel that will be running at the next boot [step 6 and later]"
So... your file impacts the NEXT /bsd that will boot...not the one
you happen to tell it to boot at the boot> prompt.
I suspect you (and I, initially) took "system startup" to mean "kernel
loading" -- no, kernel config is done during relinking, NOT during load,
and is part of the operation AFTER the system is multi-user, but not
before you can say it is finished starting.
BUT -- you aren't booting /bsd -- you override and booted /bsd.sp --
which a simple "ls -l /bsd*" will show you has NOT been modified:
$ ls -l /bsd*
-rwx------ 1 root wheel 32283298 Nov 22 01:03 /bsd*
-rwx------ 1 root wheel 32271586 Nov 21 23:42 /bsd.booted*
-rw------- 1 root wheel 4804509 Oct 13 08:07 /bsd.rd
-rwx------ 1 root wheel 32162643 Oct 13 08:07 /bsd.sp*
$ uptime
8:26PM up 8 days, 20:23, 3 users, load averages: 0.00, 0.01, 0.00
Though keep in mind, sometimes my role in life is to provide a wrong
answer so the smart people will have an opportunity to jump up and
down and point out how stupid I am, and provide the right answer. :)
As for your actual problem -- SOME video systems really don't like to
boot or run if a monitor is not attached. There are "cheater plugs"
("HDMI Dummy Plugs") made that will plug into an HDMI port and
convince the GPU a monitor is attached. Apparently, they are often
used in cryptomining, maybe AI, using GPUs as processors rather than
displays. Pretty cheap, under $10ea. I've got a few machines that
need these to do sysupdates, bsd.rd will not work without an attached
monitor, the full kernels will.
Nick.
