Execute Linux on AMD DB-FT3b-LC through GRUB2

[Grigore Lupescu]

Hello,

I am trying to run Linux through the GRUB2 payload. I am not tied to GRUB2
but it's the only payload that gives me HDMI output (board has no serial
port) using Coreboot and AMD FT3B-LC.

I have the latest Coreboot sources, have set config accordingly (e.g.
CONFIG_MAINBOARD_SMBIOS_PRODUCT_NAME="DB-FT3b-LC"...), getting an image on
HDMI and the GRUB2 payload is executing.
In GRUB2 payload I seem to have an overflow issue possibly related to the
*vga_text* mode. If I put a proprietary AMI BIOS, GRUB2 works without issue
in gfxterm mode and boots Linux without issue.

Using Coreboot every time the screen gets full of text, GRUB2 re-executes.
If I though set the terminal_output to cbmemc then commands would execute
but Linux still fails to execute - at the end GRUB2 would restart.

Also the GRUB2 payload on Coreboot does see the drive/files and attempts to
execute - I looks like a GRUB2/Coreboot config/code problem.

I execute the below in GRUB2 (which work on AMI BIOS + GRUB2).
grub> set root=(hd0,gpt2)
grub> linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda2
grub> initrd /boot/initrd.img-3.13.0-29-generic
grub> boot

1. Would anyone have any recommendation about the overflow in GRUB2 payload
? - related to Coreboot.
2. Any suggestions on booting Linux given this board's limitations on
output (HDMI only) ?

Thank you,
Grigore