actual boot device

[Sergey Lyubka]

> The best you can do is search your mountpoints and see whether any of
> them has a "/kernel" file.  The bootblock (and loader) uses the BIOS to
> read the kernel file, so it's possible that the device may not even be
> accessible from the running system.  If, for example, you booted off a
> floppy but didn't have the floppy drivers in the kernel.

Yes, that makes sense, the boot device may not be even accessible.
As I said, I am running picobsd-like system, it's / embedded into kernel
so / mountpoint is /dev/md0 :-)

I was thinking the kernel set some sysctl or something after getting
parameters from  bootblocks/loader, and user may read this something.

Probably kenv loaddev is the answer, my problem is that I cannot fit
loader into the image - it is already packed enough.

Thanks for the answers.