An experimental x86 bootloader written in Rust and inline assembly.
The simplest way to use the bootloader is in combination with the bootimage tool. With the tool installed, you can add a normal cargo dependency on the
bootloader crate to your kernel and then run
bootimage build to create a bootable disk image. You can also execute
bootimage run to run your kernel in QEMU (needs to be installed).
To compile the bootloader manually, you need to invoke
cargo xbuild with a
KERNEL environment variable that points to your kernel executable (in the ELF format):
KERNEL=/path/to/your/kernel/target/debug/your_kernel cargo xbuild
As an example, you can build the bootloader with example kernel from the
example-kernel directory with the following commands:
cd example-kernel cargo xbuild cd .. KERNEL=example-kernel/target/x86_64-example-kernel/debug/example-kernel cargo xbuild --release
This results in a bootloader executable at
target/x86_64-bootloader.json/release/bootloader. This executable is still an ELF file, which can't be run directly.
To run the compiled bootloader executable, you need to convert it to a binary file. You can use the
llvm-objcopy tools that ships with the
llvm-tools-preview rustup component. The easiest way to use this tool is using
cargo-binutils, which can be installed through
cargo install cargo-binutils. Then you can perform the conversion with the following command:
cargo objcopy -- -I elf64-x86-64 -O binary --binary-architecture=i386:x86-64 \ target/x86_64-bootloader/release/bootloader target/x86_64-bootloader/release/bootloader.bin
You can run the
bootloader.bin file using QEMU:
qemu-system-x86_64 -drive format=raw,file=target/x86_64-bootloader/release/bootloader.bin
Or burn it to an USB drive to boot it on real hardware:
dd if=target/x86_64-bootloader/release/bootloader.bin of=/dev/sdX && sync
Where sdX is the device name of your USB stick. Be careful to choose the correct device name, because everything on that device is overwritten.
The bootloader crate can be configured through some cargo features:
vga_320x200: This feature switches the VGA hardware to mode 0x13, a graphics mode with resolution 320x200 and 256 colors per pixel. The framebuffer is linear and lives at address
recursive_page_table: Maps the level 4 page table recursively and adds the
recursive_page_table_addressfield to the passed
map_physical_memory: Maps the complete physical memory in the virtual address space and passes a
physical_memory_offsetfield in the
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.