lowRISC/ibex

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Ibex is a small 32-bit RISC-V CPU core with high-level of verification (previously known as zero-riscy)

Stars: 2.1k
Forks: 810
Open beginner issues: 0
Indexed issues: 205
Avg merge: 5d 23h
Merged PRs (30d): 9

Dominant language: SystemVerilog
License: Apache-2.0
Last GitHub push: Sep 17, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: No code of conduct
Beginner labels: good first issue

Beginner friendly Everything

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205 issues indexed so far

[pmp]: MML incorrectly suppresses `pmpcfg` writes for OFF and invalid TOR entries Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 52/100

lowRISC/ibex#2491 · Opened Sep 3, 2026
[pmp]: Custom `PMPRstCfg` values bypass PMP WARL normalization Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 64/100

lowRISC/ibex#2490 · Opened Sep 3, 2026
[cheriot,rtl] ECC mismatch on CHERIoT mode switch Open

lowRISC/ibex#2480 · 1 comment · 1 assignee · Opened Aug 21, 2026
[cheriot,rtl] Add shadow copies for the capability CSRs Open

lowRISC/ibex#2478 · 1 assignee · Opened Aug 20, 2026
[cheriot,rtl] Decide whether Zcmp can be supported in CHERIoT mode Open

lowRISC/ibex#2477 · 1 assignee · Opened Aug 20, 2026
rvfi_mem_rmask is non-zero on instructions that make no memory access Open

Difficulty 4/5 3-5 days Newbie friendliness 68/100

lowRISC/ibex#2476 · 1 comment · Opened Aug 20, 2026
[pmp/debug]: Debug Mode data access uses `mstatus.MPRV` when `dcsr.mprven=0` Open

Type:Bug

lowRISC/ibex#2474 · 2 comments · 1 assignee · Opened Aug 14, 2026
[pmp/debug]: DRET to U-mode does not clear `mstatus.MPRV` Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 62/100

lowRISC/ibex#2473 · 1 comment · Opened Aug 13, 2026
[ci] Add Asecent Lint to private CI as is done in OpenTitan Open

lowRISC/ibex#2472 · 1 assignee · Opened Aug 12, 2026
Consider clear-dominant fetch FIFO payload updates Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

lowRISC/ibex#2469 · 1 comment · Opened Aug 10, 2026
[bitmanip,dv] Verify `Zbkb` and `Zbkx` with `riscv-dv` Open

Difficulty 3/5 1-2 days Newbie friendliness 48/100

lowRISC/ibex#2468 · Opened Aug 6, 2026
[cheriot,trvk] Add TRVK to lockstep operation Open

lowRISC/ibex#2467 · 1 assignee · Opened Aug 5, 2026
[cheriot,trvk] Include TRVK filter in Ibex DV Open

Difficulty 4/5 3-5 days Newbie friendliness 52/100

lowRISC/ibex#2466 · Opened Aug 5, 2026
[doc] Update outdated parts of the documentation Open

Component:Doc

lowRISC/ibex#2464 · 2 assignees · Opened Jul 29, 2026
How to read RTL files in order properly with yosys + slang plugin Ibex. (not expert, just new here) Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 38/100

lowRISC/ibex#2462 · 2 comments · 1 reaction · Opened Jul 16, 2026
[DV] Add regression tests for Zcmp instruction traps and atomicity Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

lowRISC/ibex#2461 · 2 comments · 1 reaction · Opened Jul 16, 2026
Trying another example Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 38/100

lowRISC/ibex#2453 · 1 comment · Opened Jun 12, 2026
Expose IC_SIZE_BYTES as a module parameter in ibex_top Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 55/100

lowRISC/ibex#2401 · 2 comments · Opened May 5, 2026
[dv/formal]: With Yosys and rIC3 fails for python conductor.py prove. Open

Type:Bug

Difficulty 3/5 1-2 days Newbie friendliness 38/100

lowRISC/ibex#2373 · 3 comments · Opened Mar 10, 2026
Surelog syntax error when parsing ibex_core.f (Syntax error: no viable alternative at input 'ibex_top.',) Open

Type:Question

Difficulty 3/5 1-2 days Newbie friendliness 35/100

lowRISC/ibex#2372 · 2 comments · Opened Feb 28, 2026
PLIC claim process with Ibex Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 25/100

lowRISC/ibex#2360 · Opened Jan 27, 2026
MemECC - possible spurious store-response alerts Open

Type:Bug

Difficulty 3/5 1-2 days Newbie friendliness 48/100

lowRISC/ibex#2342 · Opened Dec 5, 2025
MemECC - misaligned memory access masks out ECC bits Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 45/100

lowRISC/ibex#2341 · Opened Dec 5, 2025
RVFI CSR support Open

Type:Question

Difficulty 5/5 Over a week Newbie friendliness 30/100

lowRISC/ibex#2335 · 1 comment · Opened Nov 28, 2025
Report traps and privilege level in trace Open

Difficulty 3/5 1-2 days Newbie friendliness 42/100

lowRISC/ibex#2334 · 5 comments · Opened Nov 27, 2025
Ask a question related to Ibex Open

Type:Question

Difficulty 3/5 1-2 days Newbie friendliness 25/100

lowRISC/ibex#2333 · 1 comment · Opened Nov 19, 2025
[SecureIbex] OpenOCD attach fails when SecureIbex=1 (works when SecureIbex=0) Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 28/100

lowRISC/ibex#2323 · Opened Sep 24, 2025
[dv] Formal flow dependency Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

lowRISC/ibex#2321 · 2 comments · Opened Sep 19, 2025
[dv/formal] Relax memory bounds for open source formal flow Open

Component:DV Type:Enhancement

Difficulty 4/5 3-5 days Newbie friendliness 35/100

lowRISC/ibex#2320 · Opened Sep 19, 2025
Wrong MEPC saved with branch predictor configuration Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 45/100

lowRISC/ibex#2319 · 3 comments · Opened Sep 9, 2025
[dv,TestFW] Cosim mismatches due to dside access misidentified as iside Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 35/100

lowRISC/ibex#2314 · 1 comment · Opened Aug 28, 2025
[rtl] IbexSimpleSystem missing instruction address check Open

Type:Bug

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

lowRISC/ibex#2311 · 4 comments · Opened Aug 24, 2025
Add CITATION.cff for Standardized Ibex Citations Open

Type:Question

Difficulty 2/5 1-3 hours Newbie friendliness 35/100

lowRISC/ibex#2310 · 1 comment · Opened Aug 21, 2025
Q: Are there adapters to connect an AXI subsystem to the Ibex simple system? Open

Type:Question

Difficulty 5/5 Over a week Newbie friendliness 25/100

lowRISC/ibex#2305 · Opened Aug 6, 2025
Ask a question related to Ibex alu bitcounting Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 35/100

lowRISC/ibex#2294 · 3 comments · Opened Jul 13, 2025
make run-simple-system failure Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 35/100

lowRISC/ibex#2288 · 1 comment · Opened Jun 23, 2025
Generate coverage report error Open

Type:Question

Difficulty 5/5 Over a week Newbie friendliness 20/100

lowRISC/ibex#2281 · 1 comment · Opened May 27, 2025
Store instructions fetched from non-executable memory update data_we_o, data_addr_o, and data_wdata_o Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 38/100

lowRISC/ibex#2278 · 5 comments · Opened May 19, 2025
Facing issue with ibex DUT Open

Difficulty 4/5 3-5 days Newbie friendliness 18/100

lowRISC/ibex#2264 · 5 comments · Opened Apr 8, 2025
having issue with PKG_CONFIG_PATH Open

Type:Question

Difficulty 3/5 1-2 days Newbie friendliness 25/100

lowRISC/ibex#2263 · 12 comments · Opened Apr 4, 2025
failed to synthesize RTL with Yosys Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 32/100

lowRISC/ibex#2260 · 1 comment · Opened Mar 5, 2025
Ibex data memory interface through and bus adapters Open

lowRISC/ibex#2258 · 1 comment · 1 assignee · Opened Feb 19, 2025
How reliable is the reference model of cosim? Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 25/100

lowRISC/ibex#2244 · 2 comments · Opened Jan 12, 2025
[dv] tb_cs_registers golden-model error in ePMP extension Open

Type:Bug

Difficulty 3/5 1-2 days Newbie friendliness 48/100

lowRISC/ibex#2242 · 2 comments · Opened Jan 7, 2025
How to use Ibex with mainline fusesoc Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 25/100

lowRISC/ibex#2238 · 2 comments · Opened Jan 3, 2025
Writing `mseccfg`=0x1 will jump to `_vectors_start` Open

Type:Bug

Difficulty 4/5 3-5 days Newbie friendliness 35/100

lowRISC/ibex#2237 · 6 comments · Opened Jan 2, 2025
Facing issue while running using Questa Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 15/100

lowRISC/ibex#2235 · Opened Dec 20, 2024
[dv] Verify access to Debug Module in debug mode even if disallowed by PMP Open

lowRISC/ibex#2233 · 1 assignee · Opened Dec 13, 2024
[rvfi] rvfi_pc_wdata doesn't consider mret/dret Open

Type:Bug

Difficulty 3/5 1-2 days Newbie friendliness 45/100

lowRISC/ibex#2231 · 2 reactions · Opened Dec 11, 2024
Ask a question related to Ibex Open

Type:Question

Difficulty 4/5 3-5 days Newbie friendliness 25/100

lowRISC/ibex#2222 · 3 comments · Opened Nov 12, 2024

lowRISC/ibex

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