identifying hardware for kernel config purposes

Jeff Royle lists at
Sun Jan 21 18:59:25 UTC 2007

Glenn Becker wrote:
> Hi -
> I am following along in the Handbook in my first attempt to compile a 
> custom kernel ... and once again confronting the fact that I really know 
> beans about hardware. So once I get to the "device" lines in my edited 
> copy of the GENERIC config file I start to get a little bit lost.
> I know enough to look through /var/run/dmesg.boot, and many devices make 
> themselves obvious (a DVD-ROM drive is a DVD-ROM drive is a ...) but how 
> do I identify my motherboard, for example, so I know which lines to 
> comment out (or conversely, leave in) in the kernel config file?

There are a couple places that have good comments on what each device 
is.  GENERIC kernel itself is very descriptive, for example for your 

--- snip ---
# atkbdc0 controls both the keyboard and the PS/2 mouse
device          atkbdc          # AT keyboard controller
device          atkbd           # AT keyboard
device          psm             # PS/2 mouse
--- end sip ---

Also read over NOTES it has a lot of architecture specific notes.  You 
should also read over /usr/src/sys/conf/NOTES for even more kernel options.

> If there is a good overall guide to info like this, I'd appreciate it if 
> someone would point it out to me. :^) I also get lost in the alphabet 
> soup of ATA, PCI, SCSI and so on.

You will need to do some reading into these devices in some cases if you 
are planing of customizing the kernel.

dmesg will show you everything the system detects, even if it doesn't 
have a driver.   It is upto you from that point to figure out what 
device driver (if there is one) your kernel is missing for the hardware 
and add it.

> Thanks in advance for any guidance. I didn't want to attach my whole 
> dmesg.boot file but will do so if that will help.
> Best,
> Glenn

Oh and another piece of advice, read up in the handbook on recovering 
from a kernel that will not boot.   Important to know when doing 
recompiles :)



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