kmi - ACTIVE - Kernel with migrating threads as IPC

Age	Commit message (Collapse)	Author
2023-10-09	experimenting with removing lists threads per proc	Kimplul
	+ Gives a very slight improvement to RPC speeds, but mostly cleans up code a little bit.
2023-10-09	move rpc stack handling to arch-specific code	Kimplul
	+ Fairly considerable speedup, as we don't have to look up the rpc pte every time separately, instead cacheing them. Adds an architecture specific limitation to total rpc stack size, though.
2023-08-04	add initial smp bringup	Kimplul

2023-06-04	slight optimization and brainfart fix	Kimplul

2023-06-04	visionfive2 boots	Kimplul
	+ Make 8250 serial driver more generic + Still TODO: write a tutorial on how to boot on the visionfive2
2023-06-04	visionfive2 boots until debugging is initialized	Kimplul

2023-05-29	start trying to boot on visionfive 2	Kimplul
	+ Not bootable quite yet. Among other things, I couldn't get the current starfive u-boot fork to boot, so try adding support for booting with precompiled u-boot via the `go` command. Initial testing with qemu shows that this should be possible, and if it works, might be useful in the (far) future with other slightly janky SBCs. Also, NS16550 is 8250-based, and I'm really only using the base 8250, so rename and add visionfive 2 uart to list of compatibles. Visionfive 2 is still completely untested.
2023-05-11	arbitrary load address and RAM base detection	Kimplul
	+ Both kind of go hand in hand, made sense to do both at the same time. Some parts feel slightly hacky, the loader works by placing everything on the stack and avoiding global values. Still, seems to work?
2023-05-01	update license stuff	Kimplul

2023-04-30	rename to kmi	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	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

2022-10-29	rewrite pmem	Kimplul

2022-10-22	start outlining ipc	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	riscv32 boots and advances as far as riscv64	Kimplul

2022-06-12	add license texts	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

2022-05-24	make process loading more generic	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.
2022-04-10	add clang format and run it	Kimplul

2022-03-01	make vmflags_t 16 bits	Kimplul
	lower 8 bits are reserved for arch-specific flags (but at least read/write/execute) and higher 8 bits are metadata, currently only for VM_VIRTUAL (to be used when the backing physical memory shouldn't be freed)
2022-01-07	Use #if defined(...) when not guard clause	Kimplul

2022-01-07	Prefix static functions with __	Kimplul
	+ Probably completely unnecessary stylistic thing, but I'll roll with it
2022-01-07	Steps towards better status/debugging control	Kimplul

2022-01-07	Improved header dependency tree	Kimplul

2022-01-07	Allow building with clang	Kimplul
	+ Release mode is sort of broken, as lto doesn't work with linker relaxation and turning the relaxation off causes issues with the jump from init to kernel (as I've currently implemented it, could probably be fixed with a manual jump from assembly, I'll add it to my TODO list)