kmi - ACTIVE - Kernel with migrating threads as IPC

Age	Commit message (Collapse)	Author
2022-11-21	make syscall handlers void	Kimplul

2022-11-21	possible optimisations	Kimplul

2022-11-13	improve documentation on new features	Kimplul

2022-11-13	~1.3M ipc requests	Kimplul
	+ The secret is using gravestones. I'll have to write up full documentation for the feature but essentially riscv lets us encode whatever we want into page table entries, as long as they're not active. We use this to encode highest user address that is not a zero, in that all entries in the top level are either active or gravestones. When an active entry is removed, it is either a gravestone (if there are other active entries above it) or it starts a cascade of removing entries that have been previously removed Slight runtime overhead to page mapping, pretty major advantage in rpc calls. Feature will need to be tested more thorougly, and the init program is sort of a best scenario with just one top level userspace page table entry active at a time, leading to incredibly fast context switches. Current implementation limits a process' max virtual memory to 248 GiB (in Sv39), but I don't think the missing 8 GiB is that big of a deal.
2022-11-13	~700k ipc requests	Kimplul
	+ Eliminated need for save/load_regs, now the register save area is behind a pointer which _slightly_ increases overall syscall delay, but speeds up ipc requests by a fair bit.
2022-11-13	give uvmem_map more fitting name	Kimplul
	+ It really only works with Sv39, I suppose similar structures should be added for Sv4} etc. if I ever get around to it.
2022-11-13	write init more sensibly	Kimplul
	+ Both easier to look at and now the userspace doesn't play as big of a role in the 'benchmarking' with optimizations turned on.
2022-11-12	release mode, ~600k requests	Kimplul

2022-11-12	slight optimization	Kimplul

2022-11-12	initial rpc implementations	Kimplul

2022-11-11	less buggy fork	Kimplul
	+ Not strictly done yet, but we can swap between two processes :D
2022-11-09	add basic IPI structure	Kimplul

2022-10-29	rewrite pmem	Kimplul

2022-10-22	start outlining ipc	Kimplul

2022-10-22	create impl and CAP_PROC checking	Kimplul

2022-10-22	initial high level fork imp	Kimplul

2022-10-21	beautification	Kimplul

2022-10-21	initial implementation of swap	Kimplul
	+ Slightly unsure if it should be a syscall, or if assign would be enough. Also, which thread should run in a fork/spawn? For now, old thread, though this might increase latency. Or add swap flag to these calls?
2022-10-21	initial spawn implementation	Kimplul

2022-10-21	slight optimisation to cur_tcb on riscv	Kimplul

2022-09-15	change syscalls to take 5 params and return 6	Kimplul
	+ In total, a syscall is built up of 6 values, with the first being the syscall number. Symmetrically, the first value is now a status and the following five values return "values". This allows us to cram in more info into the ipc_* functions. The performance difference is absolutely minimal, at least from my testing in qemu.
2022-09-14	add putch syscall for easier userspace debugging	Kimplul
	+ Note that it is NOT intended for end user usage, just for debugging.
2022-09-14	add canary to kernel stack	Kimplul

2022-09-14	riscv32 boots and advances as far as riscv64	Kimplul

2022-09-02	fix documentation warnings	Kimplul

2022-06-12	add license texts	Kimplul

2022-06-11	continue documentation	Kimplul

2022-06-11	continue documentation	Kimplul

2022-06-09	use doxygen todo	Kimplul

2022-06-09	continue documentation	Kimplul

2022-05-29	continue documentation efforts	Kimplul

2022-05-29	modify formatting rules	Kimplul

2022-05-29	continue documentation efforts.	Kimplul

2022-05-28	continue documenting source	Kimplul

2022-05-28	implement set_ipc on riscv	Kimplul

2022-05-28	start implementing new proc/rpc handling	Kimplul
	+ Essentially, separate root process and remote procedure call handling. I really should write down some documentation so I don't forget, but essentially: All threads share a common process virtual memory, and when a thread wants to make an rpc, it switches over to its own rpc vmem space that is linked to the remote process.
2022-05-24	make process loading more generic	Kimplul

2022-05-23	modify file gen	Kimplul

2022-05-23	new include structure, make parse easier for doxy	Kimplul

2022-05-23	switch from clang-format to uncrustify	Kimplul
	The output is close enough, and I like that uncrustify is a third-party tool, so people can install a single tool for formatting instead of having to lug around a whole toolchain. I fully expect to have to add settings to uncrustify.conf, but let's see how this goes.
2022-05-22	add @file info to all files	Kimplul
	+ Next step, start documenting contents of each file.
2022-05-22	rename vm_branch to vmem	Kimplul
	+ Closer to what it's for rather than what it is.
2022-05-22	improved tcb handling in preparation for processes	Kimplul

2022-05-21	add status info to memory mappings	Kimplul
	+ next up would probably be to start working on process/thread relationships, largely as documented. Still not entirely sure about how I want to handle fork, but I suppose I might figure it out at some point.
2022-05-21	implement timers better	Kimplul

2022-05-09	improve uapi	Kimplul

2022-04-29	continue building base for irq handling	Kimplul

2022-04-24	fix rv32 compile errors	Kimplul

2022-04-24	start initial irq handling	Kimplul
	+ Still lots todo, and I'm not entirely sure how I should handle program space switches (mainly since the kernel uses the process' stack, maybe it shouldn't?)
2022-04-23	ran clang-format	Kimplul