current and EFI boot (was Re: AMD Ryzen temp sensor)

[Ian Clark <mrrooster%gmail.com@localhost>]

On 26 January 2018 at 19:00, Christos Zoulas <christos%zoulas.com@localhost> wrote:
> On Jan 26,  6:51pm, mrrooster%gmail.com@localhost (Ian Clark) wrote:
> -- Subject: Re: AMD Ryzen temp sensor
>
[snip]
> | >
> | Tried a -current kernel against my 8 userland and it failed to start
> | init. (error 2) but got that far.
>
> Hmm, that's ENOENT, it is not finding init at all....
>
This turned out to be an issue with the boot device.

I boot using EFI (bootx64.efi), and have a GPT partitioned root with
partition 0 as the EFI system partition and partition 1 as NetBSDs
root.

On my current kernel (8.0_BETA) this works fine, I use 'boot
hd0b:netbsd.gz' to boot.

However, if I boot a current kernel it fails to boot, thinking the
root device is on the first partition. (it chooses dk0 instead of
dk1). booting with -a and entering dk1 works fine.

If I boot from a USB image however (which I assume uses the standard
bootcode) the kernel gets the root device correct. (to be clear, I'm
doing a 'boot hd4b:netbsd.gz' from the boot menu when booting from
USB, it's booting the main HD).

Whilst this is all a bit above my head I've had a quick poke around.
If I print out the device xname at the top of 'setroot' (in
kern_subr.c) I get the incorrect dk0 when booting from the EFI boot
loader, but the correct dk1 from the USB stick.

I'm afraid this is where my skills run out though.

Cheers,

Ian