M src/ds/io.c → src/ds/io.c

@@ -165,6 +165,7 @@ }
 
 void DS7IOInit(struct DS* ds) {
 	memset(ds->memory.io7, 0, sizeof(ds->memory.io7));
+	ds->memory.io7[DS_REG_IPCFIFOCNT >> 1] = 0x0101;
 }
 
 void DS7IOWrite(struct DS* ds, uint32_t address, uint16_t value) {
@@ -320,6 +321,7 @@ }
 
 void DS9IOInit(struct DS* ds) {
 	memset(ds->memory.io9, 0, sizeof(ds->memory.io9));
+	ds->memory.io9[DS_REG_IPCFIFOCNT >> 1] = 0x0101;
 }
 
 void DS9IOWrite(struct DS* ds, uint32_t address, uint16_t value) {

M src/ds/ipc.c → src/ds/ipc.c

@@ -21,11 +21,15 @@ int16_t DSIPCWriteFIFOCNT(struct DSCommon* dscore, int16_t value) {
 	value &= 0xC40C;
 	int16_t oldValue = dscore->memory.io[DS_REG_IPCFIFOCNT >> 1] & 0x4303;
 	int16_t newValue = value | oldValue;
+	// TODO: Does Enable set enabled on both ends?
 	if (DSIPCFIFOCNTIsError(value)) {
 		newValue = DSIPCFIFOCNTClearError(newValue);
 	}
 	if (DSIPCFIFOCNTIsSendClear(newValue)) {
 		CircleBufferClear(&dscore->ipc->fifo);
+		dscore->ipc->memory.io[DS_REG_IPCFIFOCNT >> 1] = DSIPCFIFOCNTFillRecvEmpty(dscore->ipc->memory.io[DS_REG_IPCFIFOCNT >> 1]);
+		newValue = DSIPCFIFOCNTFillSendEmpty(newValue);
+		newValue = DSIPCFIFOCNTClearSendClear(newValue);
 	}
 	return newValue;
 }