Commit Graph

50 Commits

Author SHA1 Message Date
Luke Wren f033cde874 Add test for readability of CSRs in U mode. Fix readback value of mstatus.mpp 2022-05-24 17:30:24 +01:00
Luke Wren 0199f48087 Add read-only counter CSRs to readability/writability tests, and fix cycleh being unreadable when U mode is not implemented 2022-05-24 16:44:03 +01:00
Luke Wren d62861159f First pass at U-mode CSR support. Bizarrely causes CXXRTL tb to not write to stdout when invoked by subprocess.run from Python. 2022-05-24 16:17:54 +01:00
Luke Wren f849517202 Split CSR addresses into separate header file 2022-05-23 15:54:37 +01:00
Luke Wren df0fd536eb Fix IRQ priority to match the priv spec 2022-05-23 12:56:37 +01:00
Luke Wren c4e81922da Don't store bit 1 of mepc on non-RVC implementations 2022-05-23 12:27:07 +01:00
Luke Wren b80b09afe5 Typo -- fully encode all 128 possible IRQs 2022-03-15 09:01:55 +00:00
Luke Wren b0b8703ea4 Support up to 128 IRQs 2022-03-13 09:27:43 +00:00
Luke Wren 96c69d0bb0 Cut in->out paths on debug halt/resume request
Should be harmless, because in practice these should always be driven from a register
in the DM, but still better to cut the path
2022-03-01 21:14:49 +00:00
Luke Wren b0d28447ab New license headers: DWTFPL -> Apache 2.0 2021-12-13 23:23:40 +00:00
Luke Wren 25b44d04cf Add more properties wrt AMO. Fix awful bugs in interaction between AMOs and prior lr/sc, prior load/store exception, or IRQ which is asserted then deasserted. Fix sc with HRESP=1 HEXOKAY=1 not clearing the local monitor (not a bug, but unfriendly). 2021-12-12 23:24:25 +00:00
Luke Wren 8a003dbbed Make mcycle/minstret inhibited by default 2021-12-12 13:55:33 +00:00
Luke Wren 2bbc3637a2 Simplify CSR update logic. Showed promise in block synth but no difference to example soc. Still cleaner RTL. 2021-12-12 00:38:30 +00:00
Luke Wren 449348f459 Fix bug where an IRQ can fire during load/store dphase, followed by dphase bus exception.
Result was that the exception would sample the IRQ vector PC rather than the load/store instruction PC.
Fix by fencing off on in-flight dphases before asserting the IRQ. This adds a cycle of jitter
to IRQs, but is required for correct operation without adding a full exception-gathering pipeline.
2021-12-07 19:24:53 +00:00
Luke Wren 6ef3503ef5 Add A bit to MISA, update docs 2021-12-07 05:10:20 +00:00
Luke Wren 93be227d8a Add (currently failing) trap entry property. Fails when an IRQ arrives during a load/store data phase which subsequently excepts. 2021-12-06 20:12:23 +00:00
Luke Wren 52ba930638 Remove useless midcr.eivect feature. Make mlei left-shift its value by 2. 2021-12-04 01:17:57 +00:00
Luke Wren c5e85dea4c Add mconfigptr CSR 2021-12-01 03:25:56 +00:00
Luke Wren 94a3d43f27 Add Hazard3's registered marchid value to hdl and docs 2021-11-28 19:53:49 +00:00
Luke Wren e7466ae4be Move DM data0 CSR into the M-custom space, and document this 2021-11-28 15:52:52 +00:00
Luke Wren 76172cdade Start filling out CSR documentation. Change misa to report X=1 because of nonstandard IRQ CSRs. 2021-11-28 06:33:35 +00:00
Luke Wren cc6a6c09ba Vaguely implement wfi 2021-11-05 18:48:42 +00:00
Luke Wren cfe16caf41 Remove some old todos 2021-09-05 22:20:40 +01:00
Luke Wren e9fccffca0 Fix break and single-step on a load/store access fault dropping the exception. Better fix for halt request on definitely-excepting stage M instruction giving unreachable next-instruction DPC. 2021-09-05 04:45:38 +01:00
Luke Wren 65bfca5fdf Fix latent bug with asynchronous debug entry during stalled load/store address phase 2021-09-04 07:49:29 +01:00
Luke Wren 8263ee3a5d Fix reporting DPC after an excepting instruction when halt request is simultaneous with exception 2021-07-24 15:31:33 +01:00
Luke Wren 155d3ba554 Tie off 1 or 2 LSBs of DPC depending on IALIGN 2021-07-23 23:09:03 +01:00
Luke Wren 279e4b4f29 Implement mstatush as hardwired-0, as required by priv-1.12 2021-07-23 21:52:01 +01:00
Luke Wren 7d24f42da9 Oops, properly fix platform IRQ mcause numbers 2021-07-19 09:32:59 +01:00
Luke Wren 65fb62901e Mask off trap entry assertion from IRQs when in debug mode. Because the IRQ is level-sensitive, this caused trap entry to be held asserted when an IRQ fired in debug mode. This was exposed by the last bug fix -- it is only seen now that MIE+MPIE shuffling is correctly disabled in debug mode. 2021-07-19 00:19:56 +01:00
Luke Wren 70443fa557 Disable shifting of MIE/MPIE stack when in or entering debug mode 2021-07-18 21:14:11 +01:00
Luke Wren d30fc46f5b Fix IRQ mcause not being set correctly when vectoring is disabled 2021-07-18 20:44:39 +01:00
Luke Wren e95b465e26 Typo in address of mcountinhibit! 2021-07-17 19:27:01 +01:00
Luke Wren 8e3dc62b97 Fiddly handshake changes for hardware single-stepping. Can now step correctly through illegal instructions 2021-07-16 20:43:24 +01:00
Luke Wren 5aca6be572 Implement data0 inside of DM instead of core, so it gets correct reset. Add dummy tselect CSR. 2021-07-16 18:28:30 +01:00
Luke Wren 011008efd1 Fix detection of exception-like vs IRQ-like halt/trap entries 2021-07-15 19:41:35 +01:00
Luke Wren 71ec9fa283 Fix exception entry not counting as a step point for dcsr.step, and mask off IRQs in step mode (we tie dcsr.stepie = 0) 2021-07-14 20:39:51 +01:00
Luke Wren 5cc483898d Add smoke test for core debug interface, and suppress bus fetch incrementing frontend level counter when in debug mode 2021-07-10 21:02:18 +01:00
Luke Wren 63d661af63 Start hacking in debug support to the core -- seems to work as well as before adding debug! 2021-07-10 18:53:48 +01:00
Luke Wren 6a38fc33a6 Allow MHARTID to be configured at instantiation 2021-07-07 16:08:08 +01:00
Luke Wren 278dc8b6a2 meie0 default to all-zeroes 2021-06-04 07:37:02 +01:00
Luke Wren af684c4e82 Some cleanup; correctly decode 16-bit EBREAK 2021-06-03 20:03:43 +01:00
Luke Wren 5f8d217395 Implement new IRQ behaviour, and change mip.meip to be masked by individual enables in meip0 2021-05-31 17:54:12 +01:00
Luke Wren 12851d3742 Bring mtvec vectoring modes in line with spec: all exceptions go to mtvec, IRQs are optionally vectored away from it if mtvec LSB is set 2021-05-30 19:52:46 +01:00
Luke Wren cec5dc4e3b Remove old MCYCLE/MCYCLEH, implement MCOUNTINHIBIT fully, always decode tied-off HPM counters 2021-05-30 19:20:53 +01:00
Luke Wren 565b76672a Make MVENDORID/MARCHID/MIMPID configurable 2021-05-30 18:42:43 +01:00
Luke Wren f23ec3f941 Don't hold back instruction in M when an IRQ entry is stalled (but do for exception entry). Now pass add and lw checks in riscv-formal with depth 15, so getting somewhere 2021-05-29 18:57:43 +01:00
Luke Wren 65075df0e5 More work on traps, delaying IRQs which arrive whilst a load/store address phase is stalled to avoid deassertion on the bus 2021-05-29 18:00:43 +01:00
Luke Wren 1b252d4bda Significant overhaul of trap handling. Exceptions now taken from stage 3 instead of stage 2 2021-05-23 11:59:46 +01:00
Luke Wren 844fa8f97f Rename hazard5 -> hazard3 2021-05-21 03:46:29 +01:00