AsyncOS

This is the repository for AsyncOS, a small hobbyist operating system which is largely unique in it's attempt at being as asyncronous as possible - nearly all system calls are non-blocking, and communication between user processes and the kernel is handled through event polling (as well as communication between kernel modules); this typically devolves into a normal, blocking kernel implementation when there are few cores on the machine, but can result in significantly improved throughput on higher-core systems.

For backwards compatability and testing purposes, AsyncOS aims to be largely POSIX compatible (though it also aims to offer much more async-friendly primitives for process control and other operations, as some fundamental POSIX operations like fork() and exec() can be very heavyweight and cannot be made asynchronous).

AsyncOS is developed in a mixture of assembly (as all operating systems are) and the Rust programming language.

Attributions

The start of the project was heavily helped through Phillip Oppermann's wonderful blog, which you can find at http://os.phil-opp.com/.

Roadmap

• Core booting code
• Memory Management
  • Simple Page abstraction (to get code running in 64-bit mode)
  • Kernel Heap
  • Rust support for using kernel heap, allow for Box, Vec, other dynamic allocations
  • Frame Allocator
  • Pagefault Handler (Basic implementation will just map page)
• Multitasking
  • Thread abstraction, context switching
  • Blocking queues
  • Lock-free channels
  • "Actor" systems or thread groups
• Filesystem
  • ext2
  • ext3
  • FAT32
  • Partition Support
  • Filesystem systemcall abstractions
• Networking (Will be expanded later)
  • Networking systemcall abstractions
• Userland
  • Systemcall Interface (sysenter?)
  • Process abstraction
  • User systemcall queues (discussions on ensuring memory-boundedness)
  • Development of sample user programs
  • AsyncOS Shell

Build Instructions

You need to have nasm, grub-mkrescue, xorriso, qemu, nightly rust optimally through rustup, and xargo installed.

For the short forseeable future, until we have a chance to set up everything to use either the Rust build tool or another, less esoteric build tool, we use Make (but absolutely no recursive make!). Building is just

make [build]

Running with qemu is

make run [KVM=true|false]

Note that KVM is on by default; as the above implies, you can disable it by KVM=false.