DomeOS

A toy x86_64 OS in Rust.

Progress log

• 08 Mar 2021: A functional syscall that prints a string to VGA. syscall.s is compiled to a freestanding Windows PE, which is embedded in the kernel binary (no filesystem!). It is loaded and executed in usermode in its own address space.

• 20 Feb 2021: A basic kernel heap

• 20 Feb 2021: Manual stack walking and resolution of symbols on panic. Involves packing the linker map into a binary format and patching it into the binary after build

• 20 Feb 2021: Startup in QEMU (it doesn't do anything yet)

Features

• x64 long mode

• Basic interrupt handling (exceptions and clock IRQ)

• Logging through serial port and VGA

• Properly resolved backtraces on panic

• Memory management

  • Physical frame allocation
  • Mapping regions of virtual memory into current address space
  • Kernel heap
  • Demand paging - physical pages only allocated when accessed
  • Guard pages
  • CoW pages
  • mmapped files

• Processes

  • Simple PE binary loader
  • Process creation and execution from hardcoded .exe blob
  • Userspace process
  • Growable userspace stacks with guard pages
  • Userspace heap
  • Basic syscall with SYSCALL/SYSRET
    • Actually useful syscalls
    • Linux/Windows syscall compatibility
  • Process lifecycle
    • Creation of address space and threads
    • Jump to executing thread in kernel/userspace
    • Scheduling/preemption
    • Exiting
  • Basic Rust std userspace implementation

• Devices

  • Keyboard/mouse
  • Filesystem
  • Networking

• ...everything else...

Building

Only tested on Linux with the Rust nightly specified in rust-toolchain.

Dependencies:

• mtools
• grub
• xorriso
• qemu
• ld

$ scons                # builds only
$ scons run            # builds and runs in qemu
$ scons run headless=1 # builds and runs in qemu with no graphical window
$ scons -c             # cleans build, might be needed before multiple consecutive `scons run` without code changes