Retain the supplied image PC+8 snapshot after successful ARM BIOS instructions. CPU data reads from outside BIOS use its byte lanes; reads inside BIOS and host inspection remain mapped reads. Keep nominal timing and diagnostic atomicity. Unknown history, Thumb BIOS execution, and missing lookahead remain explicit limits rather than guessed values.
Add original regressions for ARM/Thumb callers, all CPU modes, widths and rotation, synthetic SWI/IRQ returns, original boot provenance, context isolation, history invalidation, and device progress. No Nintendo firmware or opcode constants are used to synthesize results.
Darwin arm64 validation: 861 workspace tests and 792 core/demo tests in debug and release; 39 Python tests; native ROM windows; all ten demo smoke tests; fmt, clippy, rustdoc, and docs links. Public ARM, Thumb, and memory ROMs still pass. The public BIOS ROM still fails firmware-specific test 1, now reading its actual replacement-BIOS prefetch rather than raw vector bytes.
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.
