RISC-V Design · All levels

RISC-V Compliance Testing: Debug Playbook

Debug Playbook for RISC-V Compliance Testing.

Debug playbook

Debug Playbook for RISC-V Compliance Testing is anchored on Compliance pass rate across implemented ISA profiles and extension-specific corner-case suites.. Convert observations into mechanism-backed decisions with explicit ownership.

Freeze workload seed, binary, compiler, firmware, and platform setup.
Find earliest persistent mechanism failure in the timeline.
Build one reduced reproducer for dominant hypothesis.
Patch minimal fix with explicit rollback gate.
Rerun correctness + performance + power matrix.

Decision tree

diagram

ROOT CAUSE TREE - RISC-V Compliance Testing

Compliance pass rate across implemented ISA profiles and extension-specific corner-case suites. regressed
          |
   reproducible on fixed seed?
      /                 \
    no                   yes
    |                     |
env/tool drift       first failing domain?
                     /        |         \
                  decode    execute    memory/MMU
                    |         |            |
               control map  bypass/FU   TLB/walk/perm
                    |
         privilege/CSR side effects checked?

Stop at first confirmed mechanism, then assign explicit owner + fix proof.

Review memo template

diagram

RISC-V REVIEW MEMO - Verification & Debug / RISC-V Compliance Testing

1. Symptom
   - Failing metric: Compliance pass rate across implemented ISA profiles and extension-specific corner-case suites.
   - Failing workload slice: <name>
   - Triggering mode: <privilege/virtualization/interrupt/cache/boot>
   - Build and runtime tags: <toolchain/firmware/RTL revision>

2. Mechanism hypothesis
   - Primary mechanism: Compliance testing validates that the core and privileged architecture behavior match RISC-V specs for instructions, CSRs, traps, and memory semantics. A robust flow maps each configured extension set (for example RV32IMAC or RV64GC) to targeted test pools, enforces deterministic signature comparison, and tracks architectural mismatches with first-fail context. Teams usually combine official compliance vectors with directed corner tests for custom microarchitectural choices so spec correctness is proven before deeper performance or stress campaigns.
   - Competing hypotheses: <decode control / hazard / MMU / privilege / integration>
   - Missing evidence: <trace/counter/proof/report>

3. Proposed action
   - Smallest reversible change: <RTL/compiler/runtime/config>
   - Expected movement: <throughput/latency/tail/perf-per-watt>
   - Regression risk: correctness, security, power, timing, software compatibility

4. Signoff
   - Required artifact: Compliance matrix mapping ISA extensions, test suites, signature status, and open mismatch tickets.
   - Required owners: CPU verification lead, ISA architect, DV engineer, toolchain owner
   - Final decision: ship, bounded rollout, rollback, or escalate

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