Add sd cluster size check

If a sd is present, and its cluster size is bigger than 32k, abort installing

arm9/src/main.c

@@ -200,6 +200,13 @@ int main(int argc, char **argv)
 		messageBox("fatInitDefault()...\x1B[31mFailed\n\x1B[47m");
 	}
 
+	u32 clusterSize = getClusterSizeForPartition("sd:/");
+	if(clusterSize > 32768)
+	{
+		messageBox("Sd card cluster size is too large");
+		return 0;
+	}
+
 	//setup nand access
 	if (!fatMountSimple("nand", &io_dsi_nand))
 	{

arm9/src/storage.c

@@ -226,3 +226,32 @@ bool removeIfExists(const char* path)
 {
 	return remove(path) == 0 || errno == ENOENT;
 }
+
+// Filesystem type
+typedef enum {FS_UNKNOWN, FS_FAT12, FS_FAT16, FS_FAT32} FS_TYPE;
+//trimmed down PARTITION struct from libfat internals
+typedef struct {
+	const void* disc;
+	void*                cache;
+	// Info about the partition
+	FS_TYPE               filesysType;
+	uint64_t              totalSize;
+	sec_t                 rootDirStart;
+	uint32_t              rootDirCluster;
+	uint32_t              numberOfSectors;
+	sec_t                 dataStart;
+	uint32_t              bytesPerSector;
+	uint32_t              sectorsPerCluster;
+	uint32_t              bytesPerCluster;
+	uint32_t              fsInfoSector;
+} PARTITION;
+
+extern PARTITION* _FAT_partition_getPartitionFromPath(const char* path);
+
+u32 getClusterSizeForPartition(const char* path)
+{
+	PARTITION* p = _FAT_partition_getPartitionFromPath(path);
+	if(!p)
+		return 0;
+	return p->bytesPerCluster;
+}

arm9/src/storage.h

@@ -25,6 +25,8 @@ bool safeCreateDir(const char* path);
 //Files and directories
 bool removeIfExists(const char* path);
 
+u32 getClusterSizeForPartition(const char* path);
+
 #ifdef __cplusplus
 }
 #endif