Re: [Libreboot] Booting Windows on x60

[Denis 'GNUtoo' Carikli]

On Thu, 30 Oct 2014 14:15:57 +0100
"Garreau\, Alexandre" <address@hidden> wrote:

> Le 30/10/2014 à 12h32, hede a écrit :
> > But why providing SeaBIOS then?
> > Isn't it needless/redundant/superfluous for booting free software?
[...]
> Chainload an USB key for example.
> Yet GRUB can’t parse syslinux config correctly and not all free
> software is resumed by what GRUB support specifically.
GRUB doesn't provide BIOS interfaces, so it's not as compatible as grub
running after coreboot.
Beside bootable USB keys(like Trisquel, Parabola and so on), there are
many other uses cases.

There are some free software option roms, like ipxe or sgabios that can
be interesting. I'm mostly interested 

> Is SeaBIOS developped by coreboot people?
> Because I think actually the problem comes from SeaBIOS.
They share some infrastructure:
* There is no SeaBIOS wiki but only a page on corboot wiki if I
remember well
* They're both hosted on coreboot's gerrit
But:
* They have different mailing lists
* And they have different developers: some coreboot people do
  participate in SeaBIOS from time to time, but SeaBIOS is not only
  used by coreboot: SeaBIOS's Kconfig has several targets:
  (X) Build for coreboot
  ( ) Build for QEMU/Xen/KVM/Bochs
  ( ) Build as Compatibilty Support Module for EFI BIOS
  The first target is self-explanatory.
  For the second one: SeaBIOS is the default BIOS implementation in
  qemu and derivated projects. I'm unsure if virtualbox uses a modified
  version of SeaBIOS. Since qemu is heavily used by all the
  virtualization solution, many patches comes from people working in
  that area.
  The third one is for being an UEFI's CSM: In EFI/UEFI, the CSM is what
  permits the computer not to boot in "UEFI/EFI mode" and to boot in
  "BIOS mode".

> The fact is that this issue is interesting me too: I need a working
> SeaBIOS in order to being able to boot LiveUSB keys when syslinux is
> not well enough supported and manually booting kernels doesn’t work
> out of the box. Currently I’ve the same problem with SeaBIOS freezing
> the computer. And without BIOS I can’t chainload anything…
I'm mostly interested in booting ipxe. So I'd like it to work too.
SeaBIOS has some recent patches for the compatibility vga option rom.

> I was planning to wait SeaBIOS get stable enough, and then put it at
> main payload and configure it to directly load GRUB as a second
> payload without offering any option to boot USB or anything. This way
> computer would stay secure with a password-protected GRUB and this
> GRUB would be able to boot USB even chainloading, so I’d have all the
> boot options within only one menu: the GRUB one.
> 
> I think a such system could be interesting as libreboot default
> (although not everybody is technically able to manually boot kernels
> on liveUSB).
To do it securely, you could either:
* Modify SeaBIOS to only load grub (not a good idea).
* Strip SeaBIOS trough make menuconfig: SeaBIOS will only boot the
  payload that are in flash.
  That will delay the boot(not that important) and make the flash setup
  more complicated and brick-prone(problematic), but that will make grub
  have the BIOS interfaces you want(so way more simple for the user:
  he could boot whatever he wants).

Personally I prefer grub to load SeaBIOS and not the reverse but that
might not be what everybody wants. I also had some internal keyboard
issues doing it this way. But USB keyboard did work.

Denis.

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