litchi-rs

An x86-64 kernel with ~100% Rust (originally) in a week. The continuation of Litchi.

Try it

Make sure the Rust toolchains and qemu-system-x86_64 are installed, then simply execute...

make qemu PROFILE=release

Roadmap

Booting

• [x] Bare-metal UEFI application.
• [x] In-memory ELF program loader.
• [x] Locate kernel executable with UEFI's simple file system.
• [x] Jump into the kernel.
• [x] Prepare BootInfo and pass to the kernel.
• [ ] ...

Kernel Initializations

• [x] Serial logger.
• [x] Global Descriptor Table & Task State Segment.
• [x] Physical frame allocator, based on the boot info.
• [x] Kernel page table.
• [x] Kernel heap allocation & extern crate alloc.
• [x] Resolve ACPI table for interrupts & multiprocessors.
• [x] Trap handlers for critical faults.
• [x] Local APIC for the timer interrupt.
• [x] IO APIC for the UART serial.
• [ ] Bootstrap application processors.
• [ ] ...

User Tasks

• [x] Load embedded ELF user programs.
• [x] RAII-style user memory allocator and mapper.
• [x] User library to provide init code.
• [x] Switch to user mode.
• [x] Frame-preserving timer interrupt handler for preemption.
• [x] Round-robin task scheduler.
• [x] System calls with shared memory.
• [x] User heap allocator.
• [x] Task recycling.
• [x] Idle task with kernel privilege.
• [x] Basic priority-based scheduler.
• [x] File or device resource management.
• [x] Blocking system calls.
• [x] A basic userspace shell.
• [ ] Task spawning and forking.
• [ ] Synchronization primitives.
• [ ] Asynchronous IO.
• [ ] ...

Other Kernel Functionalities

• [x] Event-driven UART serial input handler.
• [x] Kernel task with async Rust!
• [ ] Multiprocessors.
• [ ] Simple file systems.
• [ ] IPC mechanisms.
• [ ] ...

References

• https://os.phil-opp.com
• https://github.com/BugenZhao/Litchi
• https://github.com/alesharik/distros
• https://github.com/rcore-os/rboot
• https://github.com/rcore-os/trapframe-rs
• https://osdev.org
• https://pdos.csail.mit.edu/6.828/2018/schedule.html
• ...