pico: implement ROM mirroring for small cartridges#262
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ZengGengSen wants to merge 1 commit intolibretro:masterfrom
Open
pico: implement ROM mirroring for small cartridges#262ZengGengSen wants to merge 1 commit intolibretro:masterfrom
ZengGengSen wants to merge 1 commit intolibretro:masterfrom
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Hardware-accurate ROM mirroring is now applied to all cartridges smaller than 4MB. By rounding the ROM size up to the next power-of-two and mapping it repeatedly across the 4MB window: 1. It matches real hardware mirroring behavior. 2. It prevents FAME/M68K Fetch table misses where Fetch[n] would be 0. 3. It fixes SIGSEGV crashes caused by the CPU jumping to unmapped memory regions within the cartridge space.
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Hardware-accurate ROM mirroring is now applied to all cartridges smaller than 4MB. By rounding the ROM size up to the next power-of-two and mapping it repeatedly across the 4MB window: