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32x, hacks for roms with caching related problems

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This commit is contained in:
kub 2022-12-20 21:32:24 +00:00
parent ebd9c86a6c
commit fe8f2d963e
7 changed files with 89 additions and 28 deletions
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45
pico/cart.c
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@ -1201,6 +1201,12 @@ static void parse_carthw(const char *carthw_cfg, int *fill_sram,
Pico.sv.flags &= ~SRF_EEPROM;
else if (strcmp(p, "filled_sram") == 0)
*fill_sram = 1;
else if (strcmp(p, "wwfraw_hack") == 0)
PicoIn.quirks |= PQUIRK_WWFRAW_HACK;
else if (strcmp(p, "blackthorne_hack") == 0)
PicoIn.quirks |= PQUIRK_BLACKTHORNE_HACK;
else if (strcmp(p, "marscheck_hack") == 0)
PicoIn.quirks |= PQUIRK_MARSCHECK_HACK;
else if (strcmp(p, "force_6btn") == 0)
PicoIn.quirks |= PQUIRK_FORCE_6BTN;
else {
@ -1335,6 +1341,45 @@ static void PicoCartDetect(const char *carthw_cfg)
// Unusual region 'code'
if (rom_strcmp(0x1f0, "EUROPE") == 0 || rom_strcmp(0x1f0, "Europe") == 0)
*(u32 *) (Pico.rom + 0x1f0) = CPU_LE4(0x20204520);
// tweak for Blackthorne: master SH2 overwrites stack of slave SH2 being in PWM
// interrupt. On real hardware, nothing happens since slave fetches the values
// it has written from its cache, but picodrive doesn't emulate caching.
// move master memory area down by 0x100 bytes.
// XXX replace this abominable hack. It might cause other problems in the game!
if (PicoIn.quirks & PQUIRK_BLACKTHORNE_HACK) {
int i;
unsigned a = 0;
for (i = 0; i < Pico.romsize; i += 4) {
unsigned v = CPU_BE2(*(u32 *) (Pico.rom + i));
if (a && v == a + 0x400) { // patch if 2 pointers with offset 0x400 are found
printf("auto-patching @%06x: %08x->%08x\n", i, v, v - 0x100);
*(u32 *) (Pico.rom + i) = CPU_BE2(v - 0x100);
}
// detect a pointer into the incriminating area
a = 0;
if (v >> 12 == 0x0603f000 >> 12 && !(v & 3))
a = v;
}
}
// tweak for Mars Check Program: copies 32K longwords (128KB) from a 64KB buffer
// in ROM or DRAM to SDRAM with DMA in 4-longword mode, overwriting an SDRAM comm
// area in turn. This crashes the test on emulators without CPU cache emulation.
// This may be a bug in Mars Check, since it's only checking for the 64KB result.
// Patch the DMA transfers so that they transfer only 64KB.
if (PicoIn.quirks & PQUIRK_MARSCHECK_HACK) {
int i;
unsigned a = 0;
for (i = 0; i < Pico.romsize; i += 4) {
unsigned v = CPU_BE2(*(u32 *) (Pico.rom + i));
if (a == 0xffffff8c && v == 0x5ee1) { // patch if 4-long xfer written to CHCR
printf("auto-patching @%06x: %08x->%08x\n", i, v, v & ~0x800);
*(u32 *) (Pico.rom + i) = CPU_BE2(v & ~0x800); // change to half-sized xfer
}
a = v;
}
}
}
static void PicoCartDetectMS(void)