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feat(cartridge): add explicit Flash identification and banked reads

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0xrsydn 2026-10-07 06:13:39 +07:00
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docs/usability-roadmap.md
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@ -41,11 +41,12 @@ This exposed and corrected missing firmware affine-scale initialization, without
Frame-based scenarios and the preparation adapter now make the result repeatable.
A local Emerald run now passes its initial all-device reset, master sound enable, and pulse/noise triggers.
It also passes normal serial transfers and idle multiplayer configuration.
With `--rtc`, it passes Game Pak GPIO setup and RTC calendar reads, then stops at a Flash unlock write.
With `--rtc --save-type flash128`, it passes Game Pak GPIO setup, RTC reads, and Flash identification.
It next stops at Joybus serial-mode selection.
The core has tested Direct Sound, both pulse channels, and noise channel 4.
Wave channel 3, a continuous sample stream, and desktop audio output remain missing.
See [the runtime result](research/emerald-reset.md). Flash identification and its save protocol are the next demonstrated startup requirement.
The separate save requirement remains cartridge SRAM, followed by safe host save persistence.
See [the runtime result](research/emerald-reset.md). Disconnected Joybus configuration is the next demonstrated startup requirement.
The separate save requirement includes Flash programming/erase and safe host persistence. Identification/read support is not successful saving.
SRAM is byte-addressable battery-backed save memory. Flash and EEPROM remain separate protocols.
[Paperdomo101/2048-GBA at ae36800d](https://github.com/Paperdomo101/2048-GBA/tree/ae36800dfa1314f96c4c8785b5c2d077fb731aff) is the next independent candidate.
@ -56,8 +57,9 @@ A reproducible source build or an accessible upstream ROM is needed before recor
Next implementation steps:
1. Verify SRAM bus widths, mirroring, erased state, and wait-state behavior against independent references.
2. Add explicit cartridge save-device selection and original core regressions. Keep absent-device accesses diagnostic.
1. Research the demonstrated Joybus configuration failure without inventing a connected device.
2. Extend explicit Flash selection with verified programming, erase, and busy behavior. Keep absent devices and unsupported commands diagnostic.
Add SRAM separately when the independent candidate requires it; verify its widths, mirroring, and wait behavior first.
3. Add bounded save loading and safe persistence in the desktop crate. Do not put file operations in the core.
4. Test a save/restart/load cycle across processes with original ROM instructions before external-game validation.
5. Resume the second-game run and implement demonstrated audio requirements rather than accepting writes without behavior.