SeaBIOS

SeaBIOS (previously known as LegacyBIOS) is an open-source legacy BIOS implementation, which can also be used as coreboot payload.

Use cases

Any software requiring 16-bit BIOS services benefits from SeaBIOS.

Windows XP

Windows XP has been booted on real hardware with coreboot and SeaBIOS. Some patches are required.

Windows Vista

Windows Vista (64/32 bit) has been booted on real hardware with coreboot and SeaBIOS. Some patches are required.

Windows 7 Beta

Windows 7 Beta (?? bit) has been booted on real hardware with coreboot and SeaBIOS. Some patches are required.

GRUB

GRUB works with coreboot and SeaBIOS on real hardware and boots Linux just fine.

Building

SeaBIOS

You can download the latest version of SeaBIOS through a git repository:

<source lang="bash"> $ git clone git://git.linuxtogo.org/home/kevin/seabios.git seabios $ cd seabios </source>

Alternatively, the released versions of SeaBIOS can be found at http://linuxtogo.org/~kevin/SeaBIOS/. There's also a gitweb facility to browse the latest source code online.

Edit src/config.h and set the following values:

<source lang="C">

1. define CONFIG_COREBOOT 1
2. define CONFIG_DEBUG_SERIAL 1
3. define CONFIG_PCIBIOS 0

</source>

Then:

<source lang="bash"> $ make AVOIDCOMBINE=1 </source>

(the AVOIDCOMBINE=1 is not necessary with recent gcc versions, just use make)

The final SeaBIOS payload file is out/bios.bin.elf, which can be used with coreboot v2 or v3.

coreboot

Finally, you have to build coreboot (v3 in this example) with SeaBIOS as payload:

<source lang="bash"> $ cd .. $ svn co svn://coreboot.org/repository/coreboot-v3 $ cp seabios/out/bios.bin.elf coreboot-v3/payload.elf $ cd coreboot-v3 $ make menuconfig </source>

Now enter the Payload menu and select Payload type and then An ELF executable payload file. Now exit the menu, save your settings, and build coreboot:

<source lang="bash"> $ make </source>

The file build/coreboot.rom (or build/bios.bin) is your final coreboot v3 image, which also contains the SeaBIOS payload.

Running SeaBIOS in QEMU

For running coreboot+SeaBIOS in QEMU, you need a patched version of vgabios-cirrus.bin in your build directory first:

<source lang="bash"> $ cd build $ wget http://www.coreboot.org/images/0/0d/Vgabios-cirrus.zip $ unzip Vgabios-cirrus.zip $ cd .. </source>

You can now run SeaBIOS in QEMU:

<source lang="bash"> $ qemu -L build -hda /dev/zero -serial stdio </source>

Ready-made SeaBIOS QEMU image

TODO

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