CorgOS

Setting up the build host

Ubuntu

sudo apt-get install clang llvm clang-tools lld qemu-system

Fedora

sudo dnf install clang llvm clang-tools lld qemu-system

macOS

brew install llvm lld qemu

Cloning the repo

This repo uses submodules. Please clone with git clone --recurse https://github.com/kromych/corgos or do

git submodule init
git submodule update

Building and running

Currently, this is a UEFI bootloader that logs to the serial port. It supports a configuration file to specify where to log to, and other parameters like so for x86_64:

revision = "088bf38 Update reg definitions from the aarch64-lab, refactor"
log_device = com2
log_level = trace
wait_for_start = false

or aarch64:

revision = "87b08ae Add readme"
log_device = "pl011@9000000"
log_level = trace
wait_for_start = false
walk_page_tables = false

The names of the keys come from this definition (this will be a rustdoc one day):

pub struct BootLoaderConfig {
    /// The target device for boot logging.
    pub log_device: LogDevice,
    /// Verbosity for logging.
    pub log_level: LevelFilter,
    /// Log source line and path.
    pub log_source_path: bool,
    /// Wait at the entry point until `x9` or `r9` are set to `0`.
    pub wait_for_start: bool,
    /// Walk the page tables, and dump the page table entries.
    pub walk_page_tables: bool,
    /// TImeout in seconds for the UEFI watchdog.
    pub watchdog_seconds: Option<usize>,
}

To build the project and boot with qemu, use ./run.py -a x86_64 or ./run.py -a aarch64. The UEFI log is written to fw.log, the serial logs go to serial*.log files.

To only build the project, use

# Add '-r' for the release build
./run.py -b

Look also

Many bits and pieces like the code for the serial port support, self-relocation and page table manipulation have come from my aarch64-lab project and my C++ OS roject whose name was ToyOS.