OSF Builder

This osf-builder repo is an open source repo to faciliate the development community to collaborate on Open System Firmware (OSF).

Build pre-requisites

OSF boot starts with coreboot first, then Linux kernel which then executes init, which in this case is provided by u-root.

OSF build also consists of these three stages, executed in the reverse order.

Entire build requires PLATFORM to be defined, this specifies the platform for which build is being run.

getdeps is a tool used to fetch dependencies. It can clone Git repos, fetch files, etc.
- It is configured by a JSON file that must be specified in CONFIG.
- CONFIG consists of three top-level sections: initramfs, kernel and coreboot that specify what to fetch for each of the stages.
Initramfs image is built first, by building u-root with certain set of commands.
- initramfs section of the CONFIG is executed by getdeps to fetch the u-root sources and the Go toolchain.
- PATCHES_DIR/initramfs-PLATFORM-* patches are applied.
- Default set of commands can be found in Makefile.inc UROOT_BASE_CMDS, it can be augmented with UROOT_ADDITIONAL_CMDS or replaced entirely.
- Additional commands can come from u-root itself or from external packages, in which case UROOT_ADDITIONAL_GOPATH may be required.
- Initramfs can embed binary utilities, files can be added through UROOT_ADDITIONAL_FILES as local_path:initramfs_path pairs.
Kernel is built next
- kernel section of the CONFIG is executed by getdeps to fetch the kernel source.
- PATCHES_DIR/kernel-PLATFORM-* patches are applied.
- KERNEL_CONFIG is used as .config.
Coreboot is built last
- coreboot section of the CONFIG is executed by getdeps to fetch the source and toolchain dependencies.
- PATCHES_DIR/coreboot-PLATFORM-* patches are applied.
- COREBOOT_CONFIG is used as .config.
- Resulting flahs image is written to osf-PLATFORM.rom in the current directory.

Clone the repo.
cd examples/qemu
Run make
Once the build is completed, run make run, it will start a VM with the OSF BIOS image.

To speed up builds, when not actively working on initramfs or the kernel, pass ALWAYS_BUILD_INITRAMFS=0 and ALWAYS_BUILD_KERNEL=0 respectively.
- make ALWAYS_BUILD_INITRAMFS=0 ALWAYS_BUILD_KERNEL=0 - for hacking on coreboot only.
make clean will clean all the components without wiping the work done by getdeps.
- make clean-coreboot and make clean-kernel will clean just the coreboot and kernel components.
make wipe will wipe everything, including downloaded deps.
- make wipe-coreboot and make wipe-kernel will clean just the coreboot and kernel components.
- Note that toolchain cache survives wipe and will be used in the next build.

OSF Builder is MIT licensed, as found in the LICENSE file.