LinuxBoot is a firmware that replaces specific firmware functionality like the UEFI DXE phase with a Linux kernel and runtime. It is built-in UEFI image like an application as it will be executed at the end of DXE phase.
The LinuxBoot binary, named flashkernel, consists of Linux kernel and initramfs generated using u-root. It is built completely from the linuxboot/linuxboot repository.
This provides instructions to build a EDK2+LinuxBoot FD (Flash Device) image for Ampere's platforms.
Before building, please make sure that your build system has the following tools installed:
- golang
- Cross-compiler for Arm64 if needed.
Step 1: Clone the linuxboot repository
git clone --branch master https://github.com/linuxboot/linuxboot.gitStep 2: Building LinuxBoot binary
GO111MODULE=off make -C linuxboot/mainboards/ampere/jade fetch flashkernel ARCH=arm64Notes: If using cross-compilation, append argument CROSS_COMPILE=${CROSS_COMPILE} pointing to the cross compiler.
You can use the helper script linuxboot-bin-build.sh provided in this repository to build the LinuxBoot binary. The command is as follows:
./linuxboot-bin-build.shStep 3: Copy the flashkernel to the edk2-platforms/Platform/Ampere/LinuxBootPkg/AArch64/
cp linuxboot/mainboards/ampere/jade/flashkernel edk2-platforms/Platform/Ampere/LinuxBootPkg/AArch64/flashkernelcd edk2-platforms && build -a AARCH64 -t GCC5 -b RELEASE -p Platform/Ampere/JadePkg/JadeLinuxBoot.dscThe resulting image will be at
edk2-platforms/Build/Jade/RELEASE_GCC5/FV/BL33_JADE_UEFI.fd