Write support for NTR saves

Why does this work? We are writing flash memories without erasing them,
and writing pages without regard to alignment. Yet it works?

arm9/source/filesys/fsperm.c

@@ -69,7 +69,7 @@ bool CheckWritePermissions(const char* path) {
         snprintf(area_name, 16, "game images");
     } else if (drvtype & DRV_CART) {
         perm = PERM_CART;
-        snprintf(area_name, 16, "gamecarts");
+        snprintf(area_name, 16, "gamecart saves");
     } else if (drvtype & DRV_VRAM) {
         perm = PERM_VRAM;
         snprintf(area_name, 16, "vram0");
@@ -100,7 +100,7 @@ bool CheckWritePermissions(const char* path) {
         return true;
     
     // offer unlock if possible
-    if (!(perm & (PERM_VRAM|PERM_CART|PERM_GAME|PERM_XORPAD))) {
+    if (!(perm & (PERM_VRAM|PERM_GAME|PERM_XORPAD))) {
         // ask the user
         if (!ShowPrompt(true, "Writing to %s is locked!\nUnlock it now?", area_name))
             return false;
@@ -169,6 +169,10 @@ bool SetWritePermissions(u32 perm, bool add_perm) {
             if (!ShowUnlockSequence(2, "You want to enable SD data\nwriting permissions.\n \nThis enables you to modify\ninstallations, user data &\nsavegames."))
                 return false;
             break;
+        case PERM_CART:
+            if (!ShowUnlockSequence(2, "You want to enable gamecart\nsave writing permissions."))
+                return false;
+            break;
         #ifndef SAFEMODE
         case PERM_SYS_LVL2:
             if (!ShowUnlockSequence(3, "!Better be careful!\n \nYou want to enable SysNAND\nlvl2 writing permissions.\n \nThis enables you to modify\nirrecoverable system data!"))

arm9/source/filesys/fsperm.h

@@ -16,7 +16,7 @@
 #define PERM_MEMORY     (1UL<<10)
 #define PERM_GAME       (1UL<<11) // can't be enabled, placeholder
 #define PERM_XORPAD     (1UL<<12) // can't be enabled, placeholder
-#define PERM_CART       (1UL<<13) // can't be enabled, placeholder
+#define PERM_CART       (1UL<<13)
 #define PERM_VRAM       (1UL<<14) // can't be enabled, placeholder
 #define PERM_BASE       (PERM_SDCARD | PERM_IMAGE | PERM_RAMDRIVE | PERM_EMU_LVL0 | PERM_SYS_LVL0)
 
@@ -24,7 +24,7 @@
 #define PERM_BLUE       (GetWritePermissions()&PERM_MEMORY)
 #define PERM_RED        (GetWritePermissions()&(PERM_SYS_LVL3&~PERM_SYS_LVL2))
 #define PERM_ORANGE     (GetWritePermissions()&(PERM_SYS_LVL2&~PERM_SYS_LVL1))
-#define PERM_YELLOW     (GetWritePermissions()&((PERM_SYS_LVL1&~PERM_SYS_LVL0)|(PERM_EMU_LVL1&~PERM_EMU_LVL0)|(PERM_SDDATA&~PERM_SDCARD)))
+#define PERM_YELLOW     (GetWritePermissions()&((PERM_SYS_LVL1&~PERM_SYS_LVL0)|(PERM_EMU_LVL1&~PERM_EMU_LVL0)|(PERM_SDDATA&~PERM_SDCARD)|PERM_CART))
 #define PERM_GREEN      (GetWritePermissions()&(PERM_SDCARD|PERM_IMAGE|PERM_RAMDRIVE|PERM_EMU_LVL0|PERM_SYS_LVL0))
 
 /** Check if writing to this path is allowed **/

arm9/source/gamecart/gamecart.c

@@ -247,7 +247,7 @@ u32 ReadCartSave(u8* buffer, u64 offset, u64 count, CartData* cdata) {
     return (SPIReadSaveData((CardType) cdata->save_type, offset, buffer, count) == 0) ? 0 : 1;
 }
 
-u32 WriteCartSave(u8* buffer, u64 offset, u64 count, CartData* cdata) {
+u32 WriteCartSave(const u8* buffer, u64 offset, u64 count, CartData* cdata) {
     if (offset >= cdata->save_size) return 1;
     if (offset + count > cdata->save_size) count = cdata->save_size - offset;
     return (SPIWriteSaveData((CardType) cdata->save_type, offset, buffer, count) == 0) ? 0 : 1;

arm9/source/gamecart/gamecart.h

@@ -30,5 +30,5 @@ u32 ReadCartSectors(void* buffer, u32 sector, u32 count, CartData* cdata);
 u32 ReadCartBytes(void* buffer, u64 offset, u64 count, CartData* cdata);
 u32 ReadCartPrivateHeader(void* buffer, u64 offset, u64 count, CartData* cdata);
 u32 ReadCartSave(u8* buffer, u64 offset, u64 count, CartData* cdata);
-u32 WriteCartSave(u8* buffer, u64 offset, u64 count, CartData* cdata);
+u32 WriteCartSave(const u8* buffer, u64 offset, u64 count, CartData* cdata);
 u32 ReadCartSaveJedecId(u8* buffer, u64 offset, u64 count, CartData* cdata);

arm9/source/gamecart/spi.c

@@ -106,7 +106,7 @@ u32 SPIGetCapacity(CardType type) {
 	else return 1 << sz[(int) type];
 }
 
-int SPIWriteSaveData(CardType type, u32 offset, void* data, u32 size) {
+int SPIWriteSaveData(CardType type, u32 offset, const void* data, u32 size) {
 	u8 cmd[4] = { 0 };
 	u32 cmdSize = 4;
 	
@@ -167,7 +167,7 @@ int SPIWriteSaveData(CardType type, u32 offset, void* data, u32 size) {
 			case FLASH_8MB:
 				return 0xC8E13404; // writing is unsupported (so is reading? need to test)
 			default:
-				return 0; // never happens
+				return -1; // never happens
 		}
 		
 		u32 remaining = end - pos;

arm9/source/gamecart/spi.h

@@ -89,7 +89,7 @@ int SPIGetCardType(CardType* type, int infrared);
 u32 SPIGetPageSize(CardType type);
 u32 SPIGetCapacity(CardType type);
 
-int SPIWriteSaveData(CardType type, u32 offset, void* data, u32 size);
+int SPIWriteSaveData(CardType type, u32 offset, const void* data, u32 size);
 int SPIReadSaveData(CardType type, u32 offset, void* data, u32 size);
 
 // int SPIEraseSector(CardType type, u32 offset);

arm9/source/virtual/vcart.c

@@ -65,7 +65,7 @@ bool ReadVCartDir(VirtualFile* vfile, VirtualDir* vdir) {
         } else if (vdir->index == 7) { // JEDEC id and status register
             strcpy(vfile->name, "jedecid_and_sreg.bin");
             vfile->size = JEDECID_AND_SREG_SIZE;
-            vfile->flags = VFLAG_JEDECID_AND_SRFG;
+            vfile->flags |= VFLAG_JEDECID_AND_SRFG;
             return true;
         }
     }
@@ -85,6 +85,14 @@ int ReadVCartFile(const VirtualFile* vfile, void* buffer, u64 offset, u64 count)
     else return ReadCartBytes(buffer, foffset, count, cdata);
 }
 
+int WriteVCartFile(const VirtualFile* vfile, const void* buffer, u64 offset, u64 count) {
+    if (!cdata) return -1;
+    if (vfile->flags & VFLAG_SAVEGAME) {
+        return WriteCartSave(buffer, offset, count, cdata);
+    }
+    return -1;
+}
+
 u64 GetVCartDriveSize(void) {
     return cart_init ? cdata->cart_size : 0;
 }

arm9/source/virtual/vcart.h

@@ -6,6 +6,6 @@
 u32 InitVCartDrive(void);
 bool ReadVCartDir(VirtualFile* vfile, VirtualDir* vdir);
 int ReadVCartFile(const VirtualFile* vfile, void* buffer, u64 offset, u64 count);
-// int WriteVCartFile(const VirtualFile* vfile, const void* buffer, u64 offset, u64 count); // no writes
+int WriteVCartFile(const VirtualFile* vfile, const void* buffer, u64 offset, u64 count);
 u64 GetVCartDriveSize(void);
 void GetVCartTypeString(char* typestr);

arm9/source/virtual/virtual.c

@@ -204,7 +204,9 @@ int WriteVirtualFile(const VirtualFile* vfile, const void* buffer, u64 offset, u
         return WriteVMemFile(vfile, buffer, offset, count);
     } else if (vfile->flags & VRT_DISADIFF) {
         return WriteVDisaDiffFile(vfile, buffer, offset, count);
-    } // no write support for virtual game / tickdb / keydb / cart / vram files
+    } else if (vfile->flags & VRT_CART) {
+        return WriteVCartFile(vfile, buffer, offset, count);
+    } // no write support for virtual game / tickdb / keydb / vram files
     
     return -1;
 }