Handle RedNAND type EmuNANDs

source/fs.c

@@ -52,13 +52,18 @@ void DeinitFS() {
     }
 }
 
-bool CheckWritePermissions(const char* path) {
-    u32 pdrv = (*path) - '0';
-    
-    if ((pdrv > 6) || (*(path+1) != ':')) {
+int PathToNumFS(const char* path) {
+    int fsnum = *path - (int) '0';
+    if ((fsnum < 0) || (fsnum >= MAX_FS) || (path[1] != ':')) {
         ShowPrompt(false, "Invalid path");
-        return false;
+        return -1;
     }
+    return fsnum;
+}
+
+bool CheckWritePermissions(const char* path) {
+    int pdrv = PathToNumFS(path);
+    if (pdrv < 0) return false;
     
     if ((pdrv >= 1) && (pdrv <= 3) && (write_permission_level < 3)) {
         if (ShowPrompt(true, "Writing to the SysNAND is locked!\nUnlock it now?"))
@@ -465,25 +470,28 @@ uint64_t GetFreeSpace(const char* path)
     DWORD free_clusters;
     FATFS *fs_ptr;
     char fsname[4] = { '\0' };
-    int fsnum = -1;
+    int pdrv = PathToNumFS(path);
+    if (pdrv < 0) return -1;
     
-    strncpy(fsname, path, 2);
-    fsnum = *fsname - (int) '0';
-    if ((fsnum < 0) || (fsnum >= 7) || (fsname[1] != ':'))
-        return -1;
+    snprintf(fsname, 3, "%i:", pdrv);
     if (f_getfree(fsname, &free_clusters, &fs_ptr) != FR_OK)
         return -1;
 
-    return (uint64_t) free_clusters * fs[fsnum].csize * _MAX_SS;
+    return (uint64_t) free_clusters * fs[pdrv].csize * _MAX_SS;
 }
 
 uint64_t GetTotalSpace(const char* path)
 {
-    int fsnum = -1;
+    int pdrv = PathToNumFS(path);
+    if (pdrv < 0) return -1;
     
-    fsnum = *path - (int) '0';
-    if ((fsnum < 0) || (fsnum >= 7) || (path[1] != ':'))
-        return -1;
-    
-    return (uint64_t) (fs[fsnum].n_fatent - 2) * fs[fsnum].csize * _MAX_SS;
+    return (uint64_t) (fs[pdrv].n_fatent - 2) * fs[pdrv].csize * _MAX_SS;
+}
+
+uint64_t GetPartitionOffsetSector(const char* path)
+{
+    int pdrv = PathToNumFS(path);
+    if (pdrv < 0) return -1;
+    
+    return (uint64_t) fs[pdrv].fatbase;
 }

source/fs.h

@@ -67,5 +67,11 @@ uint64_t GetFreeSpace(const char* path);
 /** Gets total spacein filesystem in bytes */
 uint64_t GetTotalSpace(const char* path);
 
+/** Return the offset - in sectors - of the FAT partition on the drive **/
+uint64_t GetPartitionOffsetSector(const char* path);
+
+/** Helper function to get drive number from path */
+int PathToNumFS(const char* path);
+
 /** Helper function for copying DirEntry structs */
 void DirEntryCpy(DirEntry* dest, const DirEntry* orig);

source/godmode.c

@@ -146,6 +146,7 @@ u32 GodMode() {
         if (!ShowPrompt(true, "Initialising SD card failed! Retry?"))
             return exit_mode;
     }
+    InitEmuNandBase();
     InitNandCrypto();
     InitNandFS();
     
@@ -193,6 +194,7 @@ u32 GodMode() {
                 if (!ShowPrompt(true, "Reinitialising SD card failed! Retry?"))
                     return exit_mode;
             }
+            InitEmuNandBase();
             InitNandFS();
             GetDirContents(current_dir, current_path);
             cursor = 0;

source/nand/nand.c

@@ -165,6 +165,23 @@ u8 CheckNandType(bool check_emunand)
     return NAND_TYPE_UNK;
 }
 
+bool InitEmuNandBase(void)
+{
+    if (GetPartitionOffsetSector("0:") <= getMMCDevice(0)->total_size)
+        return false;
+    
+    emunand_base_sector = 0x000000; // GW type EmuNAND
+    if (CheckNandType(true) != NAND_TYPE_UNK)
+        return true;
+    
+    emunand_base_sector = 0x000001; // RedNAND type EmuNAND
+    if (CheckNandType(true) != NAND_TYPE_UNK)
+        return true;
+    
+    emunand_base_sector = 0x000000;
+    return false;
+}
+
 u32 GetEmuNandBase(void)
 {
     return emunand_base_sector;

source/nand/nand.h

@@ -15,6 +15,7 @@ int WriteNandSectors(const u8* buffer, u32 sector, u32 count, u32 keyslot, bool
 
 u8 CheckNandType(bool check_emunand);
 
+bool InitEmuNandBase(void);
 u32 GetEmuNandBase(void);
 u32 SwitchEmuNandBase(int start_sector);