Challenges in CPU DV: Why "It Boots Linux" Is Not Verification

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" summary

CVWally is a configurable RISC‑V core that can boot Linux but that confidence proves hollow: using an RVVI tracer, Imperas DV, and RISC‑V DV random instruction streams the team finds more than 20 real, non‑trivial bugs (coverage rose from ~75% to ~92%), including pipeline‑interlock race conditions that cause kernel panics (issue 412) and a delayed-interrupt commit bug (issue 148). The environment does continuous compare against a reference model, exercises asynchronous events, and shows that boots Linux is not verification.

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" chapters (5)

1. 0:00Introduction and motivation
2. 1:48CV-Wally processor overview
3. 4:27Collaborative verification
4. 8:19Bug discovery and demo
5. 13:46Conclusion and Q&A

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