OK, so I flashed Coreboot with GRUB2 (got the "verified" message, and removed
the CMOS for a few minutes).
Problem:
I find myself directly in grub rescue I think.
ls displays "(memdisk) (ata4) (ata6) (ata8) (ata0) (ata0,msdos1)".
typing boot says I need to load the kernel first.
The liveCD is active, but I don't know which command to use precisely.
here
https://askubuntu.com/questions/884814/how-to-get-out-of-grub-rescue-and-install-windows
it says:
If you are using a bootable USB and you still get to grub rescue it means you
are not booting from your USB at all.
First of all you need to find out why you are not able to boot from your USB
and fix that.
After this you should boot from the Ubuntu live CD and format the hard disk
Now I only have the CD inserted, no liveUSB.
Basically, I can't boot from the liveCD, I only get directly to grub rescue.