This is a bootloader and kernel written nearly entirely in Rust with no third party dependencies at all. Everything in this code base is all you need code wise.
To build this you need Rust, nasm, and lld-link (from LLVM's linker). This
bootloader and kernel are built identically regardless of the build system. It
should build just fine on Linux, Windows, OSX, BSD, whatever.
You can get nasm here or from apt install nasm
You can get LLVM binaries here or apt install lld
You can get Rust here. You must use nightly Rust!
This project requires that you have the i586-pc-windows-msvc and
x86_64-pc-windows-msvc Rust targets installed.
rustup target add i586-pc-windows-msvc x86_64-pc-windows-msvc
Specifically nasm, lld-link, rustup, and cargo must be in your PATH. If
one of these are not in your path, you may need to create a symlink to the
specific version (eg: lld-link-10)
To build this simply run cargo run this will create a folder called pxe
that will contain the folder which needs to be exposed via a TFTP server.
Optionally, the files could be copied from the pxe folder to your existing
PXE deployment folder.
This bootloader and kernel require PXE booting. They do not support disks in any way, shape, or form. Everything is done over the network. To use this bootloader and kernel you need to set up a valid PXE boot environment. This is done with a DHCP server and a TFTP server.
The TFTP server must point to the directory containing chocolate_milk.boot
and chocolate_milk.kern. And the DHCP server should be configured to point
to using chocolate_milk.boot as the boot image. This is a BIOS specific
bootloader and will not work with EFI/UEFI.
We use a Rust-based build system found at src/main.rs. We built the build
system in Rust such that we don't have to take on any other dependencies for
the build process. This build system has some checks for installed programs
which are required for building, builds and flattens the bootloader, and
assembles the bootloader.
The bootloader is a simple i586 Rust program emit as a MSVC calling convention
PE. This is flattened by our build system src/main.rs into an
in-memory image of the loaded PE. This is then directly appended to the initial
bootloader/src/stage0.asm entry stub. Once 32-bit mode has been entered and
selectors have been set up, we branch directly into bootloader::entry()!