Gila v0.2.2 - a Rust Microkernel

Gila is a Rust microkernel OS, inspired by the Xinu embedded OS, as well as Linux. I aim to implement multitasking and different users for processes, and eventually a filesystem. I do not aim to make it POSIX-compatible, but it will likely end up sharing many features with POSIX operating systems.

Work In Progress

Gila does nothing at all right now. Check back later. Or contribute.

Licensing

Licensed under the GNU Public License v3. See LICENSE for details.

Navigating

• arch/: Architecture specific features like the display, serial, and interrupts. Each architecture is a subfolder, containing a file or module for each feature.
• boot.rs: Handles bootloader-managed data structures. Gila uses Limine. Other bootloaders are NOT supported.
• lib.rs: Glue to make all files accessible from main.rs.
• log.rs: Logging structures and singletons for logging to serial or the display.
• main.rs: The entry point that gets called by the bootloader.
• memory.rs: Types relating to memory regions and allocation.
• panic.rs: The panic handler and associated functionality.
• params.rs: Kernel parameter handler code.
• process.rs: Process types and functions.
• resources.rs: Resources that are accessible from multiple parts of the code.

Building and running

To build an ISO image that you can boot, there are several prerequisites:

• rustup command installed
• limine command installed
• xorriso command installed
• make command installed
• qemu-system-x86_64 command installed (for running)

Then run make to invoke the Makefile.

• make prepare: Installs needed Rust toolchain.
• make clean: Cleans all built files.
• make gila: Builds the kernel ELF file.
• make iso: Builds the bootable ISO with Limine installed.
• make run: Builds the ISO and boots it in QEMU.

You can install all these dependencies automatically by using nix-shell and supplying shell.nix as an argument.

TODO: The dockerfile is kinda broken and display forwarding does not work.

Kernel Parameters

Kernel parameters are passed as part of the cmdline through limine.conf. The parameters are passed as a space-delimited list of keys and values. Keys begin with a hyphen (-), and keys are separated from their values with equals signs (=). Keys can have a set of multiple values, separated by a comma (,). Gila does not currently support parameter values with spaces. That would require an actual parser.

List of current extant kernel parameters:

• -loglevel: Can be a number or string corresponding to a log level. Only one value supported.
• -logdev: A sequence of one or more values representing devices to log to. Current options are display and serial.

The default cmdline is:

-loglevel=INFO -logdev=display,serial

Credits

The linker script stuff is from limine-rust-template, which is available under the BSD 0-Clause License.