SeaBIOS

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

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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