Re: Booting Linux from coreboot+grub2

[Bean]

On Thu, May 1, 2008 at 10:30 PM, Patrick Georgi <address@hidden> wrote:
> Hi,
>
>  I just want to report that booting linux from grub2/i386-linuxbios
>  doesn't work in my tests.
>
>  To solve this, I'd propose to start from the i386-efi loader, which
>  (other than the i386-pc loader which is currently used by the linuxbios
>  platform) doesn't use the real mode code of linux (which relies on bios
>  calls)
>
>  In my tests, it mostly works (initrd has issues, but linux boots) when
>  stripping all the EFI bits, while replacing all memory allocations with
>  simple grub_malloc() calls (and not copy the real mode code at all).

I encounter similar problem when writing the linux loader for
i386-ieee1275. The fix is quite simple, besides setting ramdisk_image
and ramdisk_size, you also need to set type_of_loader to a non-zero
value:

lh->type_of_loader = 1;

>  That's probably nothing to rely on, given that the 32bit-boot
>  specification of linux gives some "hints" on where things should be
>  stored.
>
>  Some more capable memory management functions might help reconcile the
>  i386-{efi,ieee1275,linuxbios} loaders eventually, such as a generic way
>  to request "page aligned memory in the memory range (x,y) of size z", and
>  a generic way to get a memory map. Currently that seems to be done as-
>  needed in the various loaders.

That would be nice.

-- 
Bean