Problem with 12_STABLE on amd64

[Trond Endrestøl]

On Thu, 6 Jun 2019 12:04-0000, Filippo Moretti via freebsd-stable wrote:

> I have the following problem on amd-64 STABLE-12for some odd reason 
> my custom kernel no longer boot while I could build GENERIC and that 
> would boot fine.Today I wrote a new configuration kernel file 
> removing only the devices I do not have.Unfortunately the working 
> kernel was not moved to kernel.old as it would be expected and now I 
> am locked out of the system as the new kernel fail to bott with 
> error sis cannot find zroot/ROOT/default.Is there a way to recover 
> my system?SincerelyFilippo

Press 3 in the boot loader to enter the command line.

Type in these commands:

unload
load /boot/kernel/kernel
load /boot/kernel/opensolaris.ko
load /boot/kernel/zfs.ko
boot -s

Your keyboard layout is "US" at the moment. The hyphen (minus) key is 
usually on the plus key when the US keyboard layout is active and 
you're using a non-US keyboard, and slash is usually on the hyphen 
key.

Once you get to a proper Unix shell, you might want to change the 
keyboard layout to something sensible using:

kbdcontrol -l <layout>

If you have physical access to your system and bootable install media 
at hand, you could boot from said install media, select shell, and 
import your pool using:

zpool import -Nf zroot

Manually mount your rootfs, e.g.:

mount -t zfs zroot/ROOT/default /mnt

If one of these routes was successful, edit your /boot/loader.conf or 
/mnt/boot/loader.conf using edit, ed, ee, or vi, to include:

zfs_load="YES"

Mount other filesystems as needed, or reboot to see if your system has 
recovered.

-- 
Trond.