SeaBIOS

LegacyBIOS is an open-source legacy BIOS implementation, which can also be used as coreboot payload.

Building

LegacyBIOS

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

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

Alternatively, the released versions of LegacyBIOS can be found at http://linuxtogo.org/~kevin/legacybios/.

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 final LegacyBIOS 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 LegacyBIOS as payload:

$ cd ..
$ svn co svn://coreboot.org/repository/coreboot-v3
$ cp legacybios/out/bios.bin.elf coreboot-v3/payload.elf
$ cd coreboot-v3
$ make menuconfig

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:

$ make

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

Running LegacyBIOS in QEMU

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

$ cd build
$ wget http://www.coreboot.org/images/0/0d/Vgabios-cirrus.zip
$ unzip Vgabios-cirrus.zip
$ cd ..

You can now run LegacyBIOS in QEMU:

$ qemu -L build -hda /dev/zero -serial stdio

Ready-made LegacyBIOS QEMU image

TODO

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