Coreboot Builder scripts (SeaBIOS payload)

Bash scripts and config files to simplify building of Coreboot using the official coreboot-sdk docker image.

BEFORE YOU BEGIN !!!!!

SeaBIOS is a legacy BIOS payload. If you would want a UEFI payload, it is advised to use the edk2 branch

If your device has the stock BIOS installed, you must flash the BIOS chip externally first. I suggest starting with Skulls which makes that first install as painless as possible.

While the compiled Coreboot builds this repo generates can be flashed externally, see External flashable ROMs the intent of this project is to simplify updating an existing Coreboot BIOS.

Usage

./build.sh [-t <TAG>] [-c <COMMIT>] [--config] [--bleeding-edge] [--clean-slate] <model>

  --bleeding-edge              Build from the latest commit
  --clean-slate                Purge previous build directory and config
  -c, --commit <commit>        Git commit hash
  -h, --help                   Show this help
  -i, --config                 Execute with interactive make config
  -t, --tag <tag>              Git tag/version
If a tag, commit or bleeding-edge flag is not given, the latest Coreboot release will be built

Once the build is complete, you will be asked to backup the existing and flash the new rom.

NOTE: Internal flashing can only be complete if Coreboot has already been flashed externally and ifd has been unlocked.

Examples

• Build the latest release (Coreboot Releases):
  ./build.sh X230

• Build the latest commit
  ./build.sh --config --bleeding-edge X230

Device Testing

Any config denoted with an X is a device I own and have personally tested the latest configuration on.

Model	SeaBIOS	EDK2	Total size/chip configuration
T430	X	X	12Mb (8Mb + 4Mb)
W530	X	X	12Mb (8Mb + 4Mb)
X220	X	X	8Mb
X220 Tablet	X	X	8Mb
X230			12Mb (8Mb + 4Mb)
X230 Tablet	X	X	12Mb (8Mb + 4Mb)

Other models:

Model	Note
W541	WIP
X1 Carbon Gen1	WIP
x230 FHD Mod	I own one but has a short and cannot test

Bootsplash

The GIMP file for the bootsplash can be found here. If creating a custom bootsplash be sure to follow the instructions found in this Purism blog post( scroll down to "The boot splash—Beauty is Pain")

External flashable ROMs

A full externally flashable ROM can be generated using these scrips if coreboot is build with:

• Intel Firmware Descriptor (IFD)
• Intel Management Engine (ME)
• Intel Gigabit Ethernet firmware (GbE)

These are included with your stock BIOS, which you should have a backup of having read the original contends using flashrom. There is a helper function in each model's compile.sh that will compile ifdtool, extract the pieces and place them in the default spots for coreboot to locate.

Steps:

1. If the backup was created by reading from two physical chips (See Total size/chip configuration above) is from two chips, they can be concatenated together using the cat command to create a full 12Mb ROM cat my_8mb_backup.rom my_4mb_backup.rom > stock_bios.bin . If the model only have one 8mb chip, skip this step.
2. Copy the full backup ROM into the stock_bios directory under the corresponding model directory.
3. Uncomment the following line in model's config.sh file. stock_bios.bin should be changed to be the name of the file in the stock_bios directory.

# extractStockBios "$MAINBOARD" "$MODEL" "stock_bios.bin"

4. Use the --config flag to enter the config menu. Under Chipset enable the following:
   • Add Intel descriptor.bin file
   • Add Intel ME/TXE firmware
     • Verify the integrity of the supplied ME/TXE firmware
   • Strip down the Intel ME/TXE firmware
   • Add gigabit ethernet configuration