ROM rework - Githubissues

kbeckmann / PicoCart64

N64 development cart using a Raspberry Pi RP2040

BSD 2-Clause "Simplified" License

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ROM rework #41

Closed Stary2001 closed 2 years ago

Stary2001 commented 2 years ago

This PR changes how ROM data is handled, now it ends up at a fixed offset in flash. Should hopefully simplify the implementation of #21.

New flash layout:

0 - 64k: flash containing firmware
64k - 192k: SRAM backup region
0x30000: A header at the start of the ROM region: either "picocartcompress" to enable compression or anything else (currently "picocart" followed by 8 spaces).
0x30010: 16384 - 8 entry mapping table
0x308000 (+32KiB): ROM chunks (or ROM data in case of an uncompressed ROM)

kbeckmann commented 2 years ago

Thanks for the PR! I rebased the branch and made some tiny adjustments. Next up is writing a tool to build uf2 files with compressed rom data, thanks for paving the way :).