MrZLeo / orca

RISC-V Operating System

Orca 🐋 虎鲸

A RISC-V and unix-like operating system developed just for fun.

This OS has some features:

• Rust
• RISC-V ISA
• Based on rcore

Get Start

In order to set enviroment correctly, you should pay attention to your toolchains carefully.

QEMU version

We support the new version of qemu due to the rustsbi-qemu. I do all test follow new version QEMU now(qemu now have full support for macOS aarch64). Because many package managers will introduce you new version of QEMU, I think you don't need to compile QEMU by yourself any more(but if you want to try, it is nice and not quite difficult).

Use Homebrew, you can type command like:

$ brew install qemu

to get new version QEMU.

And if you are using fedora, you can use

$ sudo dnf install qemu

to get new version of QEMU.

More infomation about qemu.

Rust toolchains

• rustc nightly(I will keep following the newest rustc version)
• risc-v target: we will install them automatically by make commands which will be introduced next
• other utilities: we will install them automatically by make commands which will introduced next

Make Commands

There are lots of make commands(which will grow together with kernel), and I list them here to make you understand what to do.

Kernel Make Commands

• make build: compile os
• make qemu: run os
• make debug: build in debug mode
• make gdb: open gdb and connect to os which is started, os must be built in debug mode
• make test: build and run test
• make run: build and qemu
• make env: build the basic environment for rust compiler
• make clean: remove target directory

User Make Commands

• make build: compile user codes and modify the binary if necessary
• make clean: remove target directory

Change Log

In the beginning, orca will follow rcore tutorial to implement basic functions. There are few stages you can find in git-log that according to chapters in rcore tutorial.

2022-1-31

Basic os that can print messages by uart(you can use differnet color to output messages in kernel)

git checkout c1ba7a0b2f0829ebe878a0eff856f1a51b21b901

2022-2-3

Batch os that can run different user applications one by one(limited syscall supported)

git checkout v0.1

2022-2-7

OS that allows time slice and change differnet task to run

git checkout v0.2

2022-2-8 Test Architecture for orca

This is a test architecture for orca, which is simple but good enough to support orca kernel test.

In test directory, you can design your own test module and bind it to mod.rs. It is better to name your module like xx_test.rs

In your module, you should desigin an interface like xx_test, which contains your whole test procedure. Pay attention that your test function must be use by test_fn, which can help us record test result. After that, call it in main of mod.rs

Test functions are used like assert!() macro, but assert macro will panic if test don't pass, which can't be used to records test result.

1. Define test module mm_test.rs in directory test
2. Define test interface mm_test
3. Define variable MM_TEST_NUM to store the number of test in this module
4. Define two test function: heap_test and heap_test2
5. In mm_test(), call test function:

pub fn mm_test() {
    test!("Memory Test Start: Running {} test\n", MM_TEST_NUM);
    test!("heap test1...");
    test_fn(heap_test);
    test!("heap test2...");
    test_fn(heap_test2);
}

6. Import my module in mod.rs, call the interface mm_test

git checkout v0.2.1

2022-2-12 Virtual memory support

Orca release new version that support virtual address space. It is still a initial version, and there are few works to do in future.

Until now, these works is still transparent outside the OS.

• more capable syscall: new systime, mmap, munmap...
• more efficent task scheduler
• more efficent frame allocator
• posix interface(next version!)

git checkout v0.3

2022-3-7 Process Management and Shell Support

Orca release new version to support process and typical shell interaction mode. Now we can program useful command and compile it with kernel, and shell will provide it as built-in binary.

git checkout v0.4

2022-5-29 Way to Persistent Storage

We will develop a file system that allow us to store of os. This file system should be easy to develop and powerful enought right now. And it will use extern crate like lru and spin to achieve efficiency.

git checkout v0.5.1

References

1. xv6-riscv: an elegant educational os https://github.com/mit-pdos/xv6-riscv
2. rcore: an educational os developed by rust https://github.com/rcore-os/rCore
3. rcore-tutorial-v3: https://github.com/rcore-os/rCore-Tutorial-v3/tree/ch2-dev/os/src