Building ROM Images from Source

Libreboot’s build system is named lbmk, short for LibreBoot MaKe, and this document describes how to use it. With this guide, you can know how to compile libreboot from the available source code.

This document assumes that you are using a Linux-based system.

You may also wish to check out the lbmk maintenance manual.

eCryptfs file name limits

Do not run the build system on a eCryptfs file system, because it has very short file name limits and Libreboot’s build system deals with very long file names. We commonly get reports from this by Linux Mint users who encrypt their home directory with eCryptfs; regular LUKS encryption will do nicely.

System requirements

System requirements are documented in the maintenance manual.

Environment variables

Configuring Git

You must do this even if you are using a release archive because of the build system’s peculiarities.

git config --global user.name "John Doe"
git config --global user.email johndoe@example.com

Downloading the source

git clone https://codeberg.org/libreboot/lbmk.git
cd lbmk

Or use an equivalent release tarball.

Installing build dependencies

./mk dependencies ubuntu
./mk dependencies debian
./mk dependencies fedora41
./mk dependencies arch

If your distribution is not supported this way, read the script and install the equivalent packages yourself.

GNAT issues

As of January 2025, Debian Trixie and Debian Sid and a few other distros, provide gnat and gcc as you expect, but gnat resolves to gnat-13 and installs gcc-13 as a dependency, while gcc resolves to gcc-14 and other toolchain components correspond to this version.

The GCC/GNAT versions need to match during build time, so Libreboot’s build system hacks the PATH environmental variable, setting up symlinks, matching GNAT to GCC or GNAT to GCC. When you run ./mk dependencies debian, you get GNAT 13 and GCC 14. This seems to make most boards compile; in our testing, the KGPE-D16 board failed to compile in this configuration. This PATH hack is only done for compiling the coreboot crossgcc toolchain, and nothing else; after that, coreboot’s toolchain is used.

GNAT is used by coreboot, because some of the Intel graphics devices are initialised natively, with code written in Ada spark (called libgfxinit).

When updating from Debian stable to Debian Trixie(testing) or Sid, you should also check for orphaned packages, using aptitude search '~o'. Do this, removing what was leftover from the old release, and make sure to re-run the Debian dependencies script, but do it like this:

./mk dependencies debian --reinstall

For better reliability, you should, after running the dependencies script, remove gnat and install gnat-14 instead, which is available on this day of 3 December 2025, but currently marked experimental. When you install GNAT 14, GNAT 13 is removed but gnat (in PATH) still won’t resolve to anything. Libreboot still accommodates this, detecting and matching the GCC and GNAT versions, which would in this instance match version 14 between them, so that gnat and gcc are both in PATH at build time, resolving to v14.x. When we tested with this configuration, the KGPE-D16 images also compiled.

MIPS cross compiler

Libreboot has support for the Sony PlayStation (PS1/PSX), based on the PCSX-Redux Open BIOS. If you’re doing a full release build, and/or specifically building the PSX BIOS, you need a MIPS cross compiler.

Arch-based systems have a mipsel cross compiler available from AUR, and most Debian-based systems have a mipsel cross compiler in apt; for these, the normal dependencies installation command will provide them. We know Void Linux and Fedora don’t have a MIPS compiler, for instance.

If your distro doesn’t have the MIPS compiler available, the PlayStation page provides instructions for manual installation; please do this in addition to the normal dependencies.

Build ROM images

Libreboot MaKe (lbmk) automatically runs all necessary commands; for example, ./mk -b coreboot will automatically build the required payloads if not already compiled.

As a result, you can now (after installing the correct build dependencies) run just a single command, from a fresh Git clone, to build all ROM images:

./mk -b coreboot

or even just build specific ROM images, e.g.:

./mk -b coreboot x60

or get a list of supported build targets:

./mk -b coreboot list

Build payloads only

You can do, for example

./mk -b grub
./mk -b seabios
./mk -b u-boot

Modifying configurations

You should check the maintenance manual for specifics, but:

./mk -m coreboot x200_8mb