# riscv64 Roadmap

## Atomics/Concurrency Correctness
- [x] Finish testing and upstream concurrency-kit implementation for riscv64
- [ ] Provide and use more fine-grained memory barriers on riscv
- [ ] Create a man page documenting `mb, wmb, rmb`

## Virtual Memory/PMAP Improvements
- [ ] Rework page table bootstrap series
- [x] Implementation
- [ ] Review feedback + testing
- [ ] Improve the construction of the direct map ([PR 252891](https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=252891), [D45328](https://reviews.freebsd.org/D45328))
- [x] Implementation
- [x] Review feedback + testing
- [ ] Add support for Page-Based Memory Attributes (Svpbmt)
- [D45471](https://reviews.freebsd.org/D45471), [D45472](https://reviews.freebsd.org/D45472)
- [ ] Support PTE global bit (long in-progress work but needs rebasing and upstreaming effort)
- [ ] Possibly: investigate 'Svinval' extension, for newly defined TLB flush instructions

## Kernel Platform Improvements
- [x] Overhaul CPU identification + errara
- [x] Rework `identcpu.c`
- [x] S-mode extension parsing
- [ ] Support CPU errata/quirks
- [ ] T-HEAD
- [ ] FU740
- [ ] Multi-letter (Z*) extensions
- [ ] enable vt_efifb, vt_simplefb
- [ ] `efirt(4)` implementation
- [ ] fpu_kern(9) support
- [ ] efi_machdep.c
- [ ] Support newer SBI extensions
- [ ] Debug triggers (breakpoint/watchpoint)
- [ ] New debug console extension

## Tooling/Performance Improvements
- [ ] Implement a hwpmc class based on the [SBI PMU extension](https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/riscv-sbi.adoc#performance-monitoring-unit-extension-eid-0x504d55-pmu)
- [x] implementation
- [ ] testing/refine for review
- [x] fix dtrace -- it was non-functional last time I loaded it
- enable tests?
- [x] Follow-up on: https://reviews.freebsd.org/D28054
- [ ] Basic system profiling (self-hosted buildworld)

## Hardware Support
- StarFive VisionFive v2
- [x] Wiki Updates
- [x] busdma_bounce fix ([D34118](https://reviews.freebsd.org/D34118))
- [x] Clock/reset drivers
- [ ] Ethernet driver fixes + debugging
- [x] MMC driver fixes + debugging
- Work with contributors

## Other/Future Work
- What happened to riscv64 port builds?