macasieb / linux-builder

Scripts to build the Linux kernel from a config file and initrd from a list of programs

Linux Appliance Builder

These scripts are useful for building Linux appliances or firmware images that do not require a full user-land and have a custom kernel configuration with optional patches. It also has a script to build a unified kernel image with the initrd and command line in a signed EFI application.

linux-builder

To use, start with a linux.config file and run:

linux-builder \
    -v \
    --version 5.4.117 \
    --config linux.config

This will download Linux 5.4.117 from kernel.org, (todo verify it), unpack it, apply any patches, generate the .config file for it and then invoke a recursive make to build it in ./build.

initrd-builder

For the kernel's initial ramdisk cpio file, you might be able to just list the binaries that you want to include and then:

initrd-builder \
    -v \
    -o build/initrd.cpio.xz \
    base-initrd.conf \
    my-initrd.conf

unify-kernel

unify-kernel \
  --kernel build/vmlinuz-linux \
  --initrd build/initrd.cpio.xz \
  --commandline commandline.txt \
  -o build/bootx64.efi

---

worldbuilder

worldbuilder uses Python3 (> 3.9), make and patch, various autotools need flex/bison/m4, json-c uses cmake, openssl uses some Perl packages. linux kernel wants rsync, bc, lz4, and host-side tools need openssl

Fedora requirements:

dnf install \
  make patch gcc g++ python3 git \
  texinfo \
  bzip2 xz \
  cmake \
  perl-FindBin perl-File-Compare \
  bc lz4 openssl-devel \
  flex bison m4 elfutils-libelf-devel

Debian requirements:

apt install \
  make patch gcc g++ python3 git \
  texinfo \
  bzip2 xz-utils \
  cmake \
  bc lz4 libssl-dev flex bison m4 rsync libelf-dev

git clone https://github.com/osresearch/linux-builder
cd linux-builder
make -j64 heads

TODO: can we remove the texinfo requirement? TODO: can we reduce the @development-tools to just gcc?