1 unstable release
0.0.1 | Nov 7, 2023 |
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#21 in #efi
145KB
4K
SLoC
This crate implements a stripped down EFI runtime that can be used by bootloader implementations to provide the EFI context needed by OS loaders such as EFI stub Linux kernels, systemd-boot UKI images or even GRUB+shim.
The EFI runtime implements the following features/APIs:
- a memory map and associated page and pool allocation routines, as well as an implementation of the GetMemoryMap() EFI boot service to deliver the final memory map to the OS;
- a EFI protocol database that supports installing and uninstalling protocols, locating handle and protocol buffers and locating device paths;
- a EFI configuration table database
The following EFI features are NOT supported:
- the UEFI driver model
- asynchronous events and notifications
The runtime services related to timekeeping, the EFI variable store and reset/poweroff are left to the caller to implement, as they cannot be implemented generically. The same applies to the Stall() boot services.
Example
fn run_efi_image(
image: impl efiloader::FileLoader + Send + 'static,
mapper: impl efiloader::MemoryMapper + 'static,
random: impl efiloader::Random + 'static,
) {
let ram = 0..0x100_0000;
let memmap = efiloader::memmap::MemoryMap::new();
memmap.declare_memory_region(&ram).unwrap();
let efi = efiloader::init(
None::<&dyn efiloader::SimpleConsole>,
memmap,
mapper,
Some(random),
)
.expect("Failed to init EFI runtime");
if let Some(mut li) = efi.load_image(&image) {
let ret = li.start_image();
println!("EFI app returned {ret:?}\n");
}
}
Dependencies
~1MB
~12K SLoC