Compiling Custom Firmware

Cloning & Building ROMs

DANGER

Building and flashing your own firmware has the potential to brick your device. Do not do this unless you are sure you know what you are doing/have a way to recover from a bad flash. Some level of knowledge with using the Linux command line is required.

1. Install tools and libraries needed for coreboot:
   • Debian based distros: sudo apt install -y bison build-essential curl flex git gnat imagemagick libncurses5-dev m4 nasm python-is-python3 uuid-dev zlib1g-dev libssl-dev
   • Arch based distros: sudo pacman --needed -S base-devel curl git gcc-ada ncurses zlib nasm imagemagick
   • Redhat based distros: sudo dnf install git make gcc-gnat flex bison xz bzip2 gcc g++ ncurses-devel wget zlib-devel patch openssl libuuid-devel nasm texinfo
2. Clone the repository:
   • git clone https://github.com/mrchromebox/coreboot.git
3. cd to the coreboot folder, then build the coreboot toolchain
   • make crossgcc-i386 CPUS=$(nproc)
4. Make changes now, if needed.
   • Common changes include:
     • Replacing the default logo (Documentation/coreboot_logo.bmp)
     • Changing version string (CONFIG_LOCALVERSION)
5. Build the ROM
   • create build dir: mkdir -p ~/dev/firmware
   • ./build-uefi.sh <boardname>
     • For example, ./build-uefi.sh careena
     • ROMs will be stored in ~/dev/firmware
6. Continue onto Flashing Manually to flash