template

UEFI application template

This directory contains a minimal example of a UEFI application. Copy it to a new directory to get started.

Check out the tutorial for more instructions on how to build and run a UEFI application developed using uefi-rs.

File structure

• rust-toolchain.toml adds the UEFI targets.
• Cargo.toml shows the necessary dependencies.
• src/main.rs has a minimal entry point that initializes the uefi-services crate and exits successfully.

Building kernels which use UEFI

This template makes it easy to start building simple applications with UEFI. However, there are some limitations you should be aware of:

• The global logger / allocator can only be set once per binary. It is useful when just starting out, but if you're building a real OS you will want to write your own specific kernel logger and memory allocator.

• To support advanced features such as higher half kernel and linker scripts you will want to build your kernel as an ELF binary.

In other words, the best way to use this crate is to create a small binary which wraps your actual kernel, and then use UEFI's convenient functions for loading it from disk and booting it.

This is similar to what the Linux kernel's EFI stub does: the compressed kernel is an ELF binary which has little knowledge of how it's booted, and the boot loader uses UEFI to set up an environment for it. See the bootloader crate for an example of how uefi-rs can be used to construct a first-stage bootloader which then loads and executes an ELF kernel binary.