Fix SuperCard CF driver (#20)

It wasn't ensuring the cart was in the media state for its operations, possibly leading to issues

source/sccf/source/dldi_header.s

@@ -38,11 +38,11 @@
 	.ascii	"SCCF"
 	.word	FEATURE_MEDIUM_CANREAD | FEATURE_MEDIUM_CANWRITE | FEATURE_SLOT_GBA
 	.word	startup			@ 
-	.word	_CF_isInserted		@ 
-	.word	_CF_readSectors		@   Function pointers to standard device driver functions
-	.word	_CF_writeSectors	@ 
-	.word	_CF_clearStatus		@ 
-	.word	_CF_shutdown		@ 
+	.word	isInserted		@ 
+	.word	readSectors		@   Function pointers to standard device driver functions
+	.word	writeSectors	@ 
+	.word	clearStatus		@ 
+	.word	shutdown		@ 
 
 @---------------------------------------------------------------------------------
 _start:

source/sccf/source/iointerface.c

@@ -83,22 +83,40 @@ Modified again by loopy
 #define SC_MODE_RAM 0x5
 #define SC_MODE_MEDIA 0x3 
 #define SC_MODE_RAM_RO 0x1
-void changeMode(u8 mode) {
+static void changeMode(u8 mode) {
 	vu16 *unlockAddress = (vu16*)0x09FFFFFE;
 	*unlockAddress = 0xA55A ;
 	*unlockAddress = 0xA55A ;
 	*unlockAddress = mode ;
 	*unlockAddress = mode ;
-} 
-
+}
 
-/*-----------------------------------------------------------------
-startUp
-Initializes the CF interface
-returns true if successful, otherwise returns false
------------------------------------------------------------------*/
 bool startup(void) {
-	changeMode (SC_MODE_MEDIA);
+	changeMode(SC_MODE_MEDIA);
 	return _CF_startup(&_SCCF_Registers);
 }
 
+bool isInserted(void) {
+	changeMode(SC_MODE_MEDIA);
+	return _CF_isInserted();
+}
+
+bool clearStatus(void) {
+	changeMode(SC_MODE_MEDIA);
+	return _CF_clearStatus();
+}
+
+bool readSectors(u32 sector, u32 numSectors, void* buffer) {
+	changeMode(SC_MODE_MEDIA);
+	return _CF_readSectors(sector, numSectors, buffer);
+}
+
+bool writeSectors(u32 sector, u32 numSectors, void* buffer) {
+	changeMode(SC_MODE_MEDIA);
+	return _CF_writeSectors(sector, numSectors, buffer);
+}
+
+bool shutdown(void) {
+	changeMode(SC_MODE_MEDIA);
+	return _CF_shutdown();
+}