gamozolabs/ chocolate_milk
About the developer
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MIT License 
81 Commits 
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Description
Pure Rust x86_64 bootloader and kernel
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Summary
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.
Building
Requirements
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-msvcand
x86_64-pc-windows-msvcRust targets installed.
rustup target add i586-pc-windows-msvc x86_64-pc-windows-msvc
Specifically
nasm,
lld-link,
rustup, and
cargomust 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)
Building
To build this simply run
cargo runthis will create a folder called
pxethat will contain the folder which needs to be exposed via a TFTP server. Optionally, the files could be copied from the
pxefolder to your existing PXE deployment folder.
Usage
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.bootand
chocolate_milk.kern. And the DHCP server should be configured to point to using
chocolate_milk.bootas the boot image. This is a BIOS specific bootloader and will not work with EFI/UEFI.
Design
Build System
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.
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.rsinto an in-memory image of the loaded PE. This is then directly appended to the initial
bootloader/src/stage0.asmentry stub. Once 32-bit mode has been entered and selectors have been set up, we branch directly into
bootloader::entry()!