kernel.md

overall kernel implementation notes

Testing setup

The approach I took in laos was not so good, so I'd like to reformulate it here. There, you would compile the kernel with -DRUNTEST=<test_selection_criteria, and this would only compile in the tests you want. This means that running a different set of tests means recompiling the kernel.

There's no reason this can't be done at runtime, so the new idea is to build a test runner kernel that reads the test selection at runtime (via serial port).

kernel TODO

In no definitive order. Some of these can be copied from laos.

• quality of life
  • C++ basic runtime support (e.g., global ctors)
  • unit testing utility
  • doxygen
  • benchmarking utility
  • clang-tidy and clang-format configuration
• basics
  • printf library
  • (circular) linked lists like Linux's LIST_HEAD
• interrupts
• memory allocation
  • page frame allocator
  • slub/slab allocator
  • virtual memory allocator
• scheduling
  • kernel threads
  • setup TSS (for userspace)
  • userspace processes (after userspace)
• enter userspace
  • syscalls
  • shell
  • ELF loader
  • try to link in a very simple libc?
• drivers
  • serial port
  • keyboard
  • console
  • disk
  • timer
  • graphics (very simple)
• filesystem (I have no idea how these work)