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Implement EEPROM

This commit is contained in:
Jeffrey Pfau 2013-04-27 21:51:58 -07:00
parent f4fa423135
commit ca959c640a
3 changed files with 97 additions and 14 deletions
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28
src/gba/gba-memory.c
View File

@ -164,10 +164,15 @@ int16_t GBALoad16(struct ARMMemory* memory, uint32_t address) {
case BASE_CART1:
case BASE_CART1_EX:
case BASE_CART2:
case BASE_CART2_EX:
if ((address & (SIZE_CART0 - 1)) < gbaMemory->romSize) {
return ((int16_t*) gbaMemory->rom)[(address & (SIZE_CART0 - 1)) >> 1];
}
case BASE_CART2_EX:
if (gbaMemory->savedata.type == SAVEDATA_EEPROM) {
return GBASavedataReadEEPROM(&gbaMemory->savedata);
} else if ((address & (SIZE_CART0 - 1)) < gbaMemory->romSize) {
return ((uint16_t*) gbaMemory->rom)[(address & (SIZE_CART0 - 1)) >> 1];
}
case BASE_CART_SRAM:
break;
default:
@ -200,10 +205,15 @@ uint16_t GBALoadU16(struct ARMMemory* memory, uint32_t address) {
case BASE_CART1:
case BASE_CART1_EX:
case BASE_CART2:
case BASE_CART2_EX:
if ((address & (SIZE_CART0 - 1)) < gbaMemory->romSize) {
return ((uint16_t*) gbaMemory->rom)[(address & (SIZE_CART0 - 1)) >> 1];
}
case BASE_CART2_EX:
if (gbaMemory->savedata.type == SAVEDATA_EEPROM) {
return GBASavedataReadEEPROM(&gbaMemory->savedata);
} else if ((address & (SIZE_CART0 - 1)) < gbaMemory->romSize) {
return ((uint16_t*) gbaMemory->rom)[(address & (SIZE_CART0 - 1)) >> 1];
}
case BASE_CART_SRAM:
break;
default:
@ -356,7 +366,7 @@ void GBAStore16(struct ARMMemory* memory, uint32_t address, int16_t value) {
if (gbaMemory->savedata.type == SAVEDATA_NONE) {
GBASavedataInitEEPROM(&gbaMemory->savedata);
}
GBASavedataWriteEEPROM(&gbaMemory->savedata, value);
GBASavedataWriteEEPROM(&gbaMemory->savedata, value, 1);
break;
case BASE_CART_SRAM:
break;
@ -598,19 +608,23 @@ void GBAMemoryServiceDMA(struct GBAMemory* memory, int number, struct GBADMA* in
}
} else {
uint16_t word;
if (source >> BASE_OFFSET == BASE_CART2_EX && memory->savedata.type == SAVEDATA_EEPROM) {
if (sourceRegion == REGION_CART2_EX && memory->savedata.type == SAVEDATA_EEPROM) {
while (wordsRemaining--) {
word = GBASavedataReadEEPROM(&memory->savedata);
GBAStore16(&memory->d, dest, word);
source += sourceOffset;
dest += destOffset;
}
} else if (dest >> BASE_OFFSET == BASE_CART2_EX && memory->savedata.type == SAVEDATA_EEPROM) {
while (wordsRemaining--) {
} else if (destRegion == REGION_CART2_EX) {
if (memory->savedata.type != SAVEDATA_EEPROM) {
GBASavedataInitEEPROM(&memory->savedata);
}
while (wordsRemaining) {
word = GBALoadU16(&memory->d, source);
GBASavedataWriteEEPROM(&memory->savedata, word);
GBASavedataWriteEEPROM(&memory->savedata, word, wordsRemaining);
source += sourceOffset;
dest += destOffset;
--wordsRemaining;
}
} else {
while (wordsRemaining--) {

66
src/gba/gba-savedata.c
View File

@ -96,14 +96,68 @@ void GBASavedataWriteFlash(struct GBASavedata* savedata, uint8_t value) {
GBALog(GBA_LOG_STUB, "Flash memory unimplemented");
}
void GBASavedataWriteEEPROM(struct GBASavedata* savedata, uint16_t value) {
(void)(savedata);
(void)(value);
GBALog(GBA_LOG_STUB, "EEPROM unimplemented");
void GBASavedataWriteEEPROM(struct GBASavedata* savedata, uint16_t value, uint32_t writeSize) {
switch (savedata->command) {
// Read header
case EEPROM_COMMAND_NULL:
default:
savedata->command = value & 0x1;
break;
case EEPROM_COMMAND_PENDING:
savedata->command <<= 1;
savedata->command |= value & 0x1;
if (savedata->command == EEPROM_COMMAND_WRITE) {
savedata->addressBits = writeSize - 64 - 2;
savedata->writeAddress = 0;
} else {
savedata->addressBits = writeSize - 2;
savedata->readAddress = 0;
}
break;
// Do commands
case EEPROM_COMMAND_WRITE:
// Write
if (writeSize > 65) {
savedata->writeAddress <<= 1;
savedata->writeAddress |= (value & 0x1) << 6;
} else if (writeSize == 1) {
savedata->command = EEPROM_COMMAND_NULL;
savedata->writePending = 1;
} else {
uint8_t current = savedata->data[savedata->writeAddress >> 3];
current &= ~(1 << (0x7 - (savedata->writeAddress & 0x7)));
current |= (value & 0x1) << (0x7 - (savedata->writeAddress & 0x7));
savedata->data[savedata->writeAddress >> 3] = current;
++savedata->writeAddress;
}
break;
case EEPROM_COMMAND_READ_PENDING:
// Read
if (writeSize > 1) {
savedata->readAddress <<= 1;
if (value & 0x1) {
savedata->readAddress |= 0x40;
}
} else {
savedata->readBitsRemaining = 68;
savedata->command = EEPROM_COMMAND_READ;
}
break;
}
}
uint16_t GBASavedataReadEEPROM(struct GBASavedata* savedata) {
(void)(savedata);
GBALog(GBA_LOG_STUB, "EEPROM unimplemented");
if (savedata->command != EEPROM_COMMAND_READ) {
return 1;
}
--savedata->readBitsRemaining;
if (savedata->readBitsRemaining < 64) {
int step = 63 - savedata->readBitsRemaining;
uint8_t data = savedata->data[(savedata->readAddress + step) >> 3] >> (0x7 - (step & 0x7));
if (!savedata->readBitsRemaining) {
savedata->command = EEPROM_COMMAND_NULL;
}
return data & 0x1;
}
return 0;
}

17
src/gba/gba-savedata.h
View File

@ -11,6 +11,14 @@ enum SavedataType {
SAVEDATA_EEPROM
};
enum SavedataCommand {
EEPROM_COMMAND_NULL = 0,
EEPROM_COMMAND_PENDING = 1,
EEPROM_COMMAND_WRITE = 2,
EEPROM_COMMAND_READ_PENDING = 3,
EEPROM_COMMAND_READ = 4
};
enum {
SAVEDATA_FLASH_BASE = 0x0E005555
};
@ -19,7 +27,14 @@ struct GBASavedata {
enum SavedataType type;
uint8_t* data;
const char* filename;
enum SavedataCommand command;
int fd;
int readBitsRemaining;
int readAddress;
int writeAddress;
int writePending;
int addressBits;
};
void GBASavedataInit(struct GBASavedata* savedata, const char* filename);
@ -32,6 +47,6 @@ void GBASavedataInitSRAM(struct GBASavedata* savedata);
void GBASavedataWriteFlash(struct GBASavedata* savedata, uint8_t value);
uint16_t GBASavedataReadEEPROM(struct GBASavedata* savedata);
void GBASavedataWriteEEPROM(struct GBASavedata* savedata, uint16_t value);
void GBASavedataWriteEEPROM(struct GBASavedata* savedata, uint16_t value, uint32_t writeSize);
#endif