ACTIVE - Kernel with migrating threads as IPC https://metanimi.dy.fi/cgit/kmi/atom?h=master 2024-10-29T19:17:31Z 2024-10-29T19:17:31Z Kimplul kimi.h.kuparinen@gmail.com 2024-10-29T19:17:31Z urn:sha1:5976ad390a15726c3ddfacf8c8b282c8350f9554 2024-07-08T15:04:03Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-08T14:43:59Z urn:sha1:e134202611a50b358c147c92bfb8a7f443030b8b + Anything extern is right out as LLVM doesn't produce correct code for them. Maybe if I added some extra attributes but I'm skeptical. Replaced with static variables and getters/setters. + Inline ASM is apparently a bit buggy, so use an assembly stub when jumping to init. + Minimize work done in main() to minimize chance of LLVM doing something silly. Still not 100% certain that I shouldn't just write the main() as an assembly stub in arch/riscv64 to be absolutely sure everything works as intended. + Make .kernel.start section SHF_ALLOC, otherwise lld complains about pc-relative addressing Probably some other stuff as well that I'm forgetting right now. But at least with LLVM14 LTO seems to work, which is pretty cool? 2024-07-07T11:34:39Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-07T11:34:39Z urn:sha1:d592abd8ccc4026c51e196777031eb65c4acc4de + Align kernel to 2MiB boundary in u-boot + Optimize alignment functions a little bit, should still have to check on real hardware but 'feels' more clean + Add early boot debugging + Put extra cores we aren't ready to account for to sleep if/when they boot. + Make BASE_PAGE_SIZE constant on riscv64/32, helps the compiler with some alignment checks among other things. 2024-07-07T04:00:43Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-07T04:00:43Z urn:sha1:122374c362ba8bb9082385da3c82e264ab594f15 + Had some minor issues with a wraparound of size_t that effectively meant that some regions were allocated twice. Also, booting should be a bit more reliable now, turned out that the previous iteration of the booting was just accidentally working due to the kernel being placed 'close enough' in RAM to where it was linked to. Fixed by allocating a vmem of O1 that maps the kernel to a 2MiB boundary at boot, pretty nifty. 2024-07-06T21:49:55Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-06T21:49:55Z urn:sha1:03e12129927b0deba537a11bb5575bef93c57d0f + Apparently dbg_fdt() itself wasn't buggy, but for whatever reason GCC produced an absolute load to the prefix string in __print_prefix() which caused all the issues. Unclear why, seems like a compiler bug. This commit is more of a workaround, I'd still like to investigate this further. 2024-07-06T20:37:11Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-06T20:37:11Z urn:sha1:3fedbb6e1f849c5e0a4033d68201d60c2fc48121 + dbg_fdt() is apparently broken, possibly due to UB or something, but it causes some issues with optimizations enabled. Remove it temporarily 2024-07-06T15:14:04Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-06T15:14:04Z urn:sha1:76517486919657ecadda9867125dc6730f29a5b7 + The system is now a bit simpler and hopefully easier to understand, while also extending the shared memory to be 1:N, where there is one owner who may become a zombie while waiting for the N to die. 2024-07-05T18:02:52Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-05T18:02:52Z urn:sha1:608f44306a6f0d5692f5c81bcbfe7a621ec254ba + Start out using big kernel lock, apparently seL4 thinks its good enough. I might have a go at using a more fair lock, and possibly moving to more fine-grained locks if I really feel the need to get scalability up. 2024-07-05T17:14:46Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-05T17:14:46Z urn:sha1:83a6fc687cab3ee87c6cae1324728521f9877ad0 2024-07-05T16:38:11Z Kimplul kimi.h.kuparinen@gmail.com 2024-07-05T16:38:11Z urn:sha1:e09edb5d54e39bd9509a1dc450df5ab320759f97 + Took some fairly significant changes, for one the kernel is no longer relocated at the start of a boot, instead it sits wherever the user decides the kernel should sit. Similarly, the initial kernel stack and page table are stored within the binary, slightly bloating the size but making it much safer to boot since there's really no chance of us overwriting the fdt or initrd in memory.