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test(bios): integrate pinned BIOS read-protection baseline

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Add --suite bios with hash-verified upstream files and the ARM evaluation checkpoint at 0x08000248. Preserve the r12=0 assertion, original BIOS boot, and all test bytes. Add synthetic adapter and CLI regressions.

On Darwin arm64 the public ROM fails test 1 in debug and release after 64 steps and 543 nominal cycles. Document that this tests protected reads of Nintendo firmware opcodes, not general BIOS service compatibility. Online and offline preparation agree; 39 Python tests pass. Core behavior is unchanged.
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0xrsydn 2026-10-05 21:31:04 +07:00
commit 6e736c634b
11 changed files with 143 additions and 8 deletions
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@ -69,6 +69,7 @@ Update this file when a feature lands or a limit is removed.
- Headless JSON ROM suites with per-case checkpoints, register/CPSR/memory assertions, bounded budgets, and structured failure reports.
- Hash-pinned preparation of public `jsmolka/gba-tests` ARM, Thumb, and memory ROMs, with verified result-register checkpoints.
- These pinned ROMs pass their checkpoints on Darwin arm64 in debug and release builds; coverage limits remain documented.
- A pinned public BIOS read-protection ROM has a verified checkpoint and an explicit failing baseline with the original BIOS.
- ARM test/compare Rd=15 status restoration, without a PC result write or nominal refill.
- ARM unused-memory data reads return a PC+8 word snapshot, with normal byte lanes and load rotation.
- Little-endian byte, halfword, and word reads/writes.
@ -119,6 +120,7 @@ The [ROM suite runner](rom-tests.md) has original regressions and a [pinned publ
The pinned public ARM ROM passes its result checkpoint in debug and release builds.
The [pinned public Thumb ROM](public-thumb-tests.md) also passes after correcting its empty-list store PC value.
The [pinned public memory ROM](public-memory-tests.md) passes without a core change; its video-byte assertions have documented limits.
The [pinned BIOS read-protection ROM](public-bios-tests.md) fails test 1; it expects Nintendo firmware opcode values.
Other public suites remain unverified. These results do not establish full CPU or memory compatibility.
The runner requires known completion addresses and has no debug-port protocol, scripted input, or rendered-image assertions.
@ -132,7 +134,7 @@ Writes to cartridge addresses return errors instead of modeling cartridge hardwa
## Next steps
1. Add a pinned public BIOS suite with a verified result protocol, then address its first compatibility failure.
1. Add BIOS read protection based on supplied firmware instructions, not hard-coded values from the public BIOS test.
Extend open-bus support with verified Thumb region/alignment rules and bus history, rather than a blanket unmapped-read fallback.
2. Refine nominal timing with a fetch pipeline, Game Pak prefetch, per-access device updates, and verified timer/IRQ delays.
3. Validate keypad retrigger behavior with hardware tests and add remaining device registers; extend BIOS reset coverage as sound/serial support becomes available.