all repos — mgba @ c2f43bc503e1bfd181fdd76ead42dc67eea0b4f1

mGBA Game Boy Advance Emulator

DS Slot-1: Fix SPI addressing a bit
Vicki Pfau vi@endrift.com
Sat, 15 Apr 2017 12:03:57 -0700
commit

c2f43bc503e1bfd181fdd76ead42dc67eea0b4f1

parent

8fcf9bee070251b6f2cefc9339e2e87842d00895

2 files changed, 22 insertions(+), 2 deletions(-)

jump to
M include/mgba/internal/ds/slot1.h → include/mgba/internal/ds/slot1.h 
@@ -56,6 +56,7 @@ uint8_t statusReg;
 	int spiAddressingRemaining;
 	uint32_t spiAddress;
 	int spiAddressingBits;
+	uint32_t spiSize;
 
 	uint8_t* spiData;
 	struct VFile* spiVf;
M src/ds/slot1.c → src/ds/slot1.c 
@@ -30,6 +30,7 @@ ds->memory.slot1.savedataType = DS_SAVEDATA_AUTODETECT;
 	ds->memory.slot1.spiVf = vf;
 	ds->memory.slot1.spiRealVf = vf;
 	ds->memory.slot1.spiData = NULL;
+	ds->memory.slot1.spiSize = 0;
 }
 
 void DSSlot1Reset(struct DS* ds) {

@@ -262,12 +263,19 @@ if (!dscore->p->memory.slot1.spiData) {
 		return 0xFF;
 	}
 
+	uint8_t oldValue;
 	switch (dscore->p->memory.slot1.spiCommand) {
 	case 0x03: // RDLO
 	case 0x0B: // RDHI
-		return dscore->p->memory.slot1.spiData[dscore->p->memory.slot1.spiAddress++];
+		dscore->p->memory.slot1.spiAddress &= dscore->p->memory.slot1.spiSize - 1;
+		oldValue = dscore->p->memory.slot1.spiData[dscore->p->memory.slot1.spiAddress];
+		++dscore->p->memory.slot1.spiAddress;
+		return oldValue;
 	case 0x02: // WRLO
 	case 0x0A: // WRHI
+		if (dscore->p->memory.slot1.spiAddress >= dscore->p->memory.slot1.spiSize) {
+			break;
+		}
 		dscore->p->memory.slot1.spiData[dscore->p->memory.slot1.spiAddress] = datum;
 		++dscore->p->memory.slot1.spiAddress;
 		break;

@@ -295,14 +303,23 @@
 	uint8_t oldValue;
 	switch (dscore->p->memory.slot1.spiCommand) {
 	case 0x03: // RD
+		if (dscore->p->memory.slot1.spiAddress >= dscore->p->memory.slot1.spiSize) {
+			return 0xFF;
+		}
 		oldValue = dscore->p->memory.slot1.spiData[dscore->p->memory.slot1.spiAddress];
 		++dscore->p->memory.slot1.spiAddress;
 		return oldValue;
 	case 0x02: // PP
+		if (dscore->p->memory.slot1.spiAddress >= dscore->p->memory.slot1.spiSize) {
+			break;
+		}
 		dscore->p->memory.slot1.spiData[dscore->p->memory.slot1.spiAddress] = datum;
 		++dscore->p->memory.slot1.spiAddress;
 		break;
 	case 0x0A: // PW
+		if (dscore->p->memory.slot1.spiAddress >= dscore->p->memory.slot1.spiSize) {
+			break;
+		}
 		oldValue = dscore->p->memory.slot1.spiData[dscore->p->memory.slot1.spiAddress];
 		dscore->p->memory.slot1.spiData[dscore->p->memory.slot1.spiAddress] = datum;
 		++dscore->p->memory.slot1.spiAddress;

@@ -377,6 +394,7 @@ return false;
 	}
 	if (slot1->spiAddress >= slot1->spiVf->size(slot1->spiVf)) {
 		size_t size = toPow2(slot1->spiAddress + 1);
+		slot1->spiSize = size;
 		size_t oldSize = slot1->spiVf->size(slot1->spiVf);
 		if (slot1->spiData) {
 			slot1->spiVf->unmap(slot1->spiVf, slot1->spiData, oldSize);

@@ -415,7 +433,7 @@ ds->memory.slot1.savedataType = DS_SAVEDATA_FLASH;
 	} else {
 		ds->memory.slot1.savedataType = DS_SAVEDATA_EEPROM;
 	}
-	if (size >= 0x10000) {
+	if (size > 0x10000) {
 		ds->memory.slot1.spiAddressingBits = 24;
 	} else if (size <= 0x200) {
 		ds->memory.slot1.spiAddressingBits = 8;

@@ -424,6 +442,7 @@ } else {
 		ds->memory.slot1.spiAddressingBits = 16;
 	}
 	ds->memory.slot1.spiAddress = size - 1;
+	ds->memory.slot1.spiSize = size;
 	_slot1GuaranteeSize(&ds->memory.slot1);
 }