Added FIRM version detection, removed firmware.bin loading unless an unsupported O3DS NATIVE_FIRM (pre-5.0) is being loaded, skip patching old unsupported O3DS AGB/TWL FIRMs, only apply 11.0 patches with 11.0 or greater

source/firm.c

@@ -218,18 +218,19 @@ void main(void)
         }
     }
 
-    loadFirm(firmType, firmType == NATIVE_FIRM && firmSource == ((updatedSys) ? FIRMWARE_SYSNAND : FIRMWARE_EMUNAND));
+    u32 firmVersion = loadFirm(firmType);
 
     switch(firmType)
     {
         case NATIVE_FIRM:
-            patchNativeFirm(nandType, emuHeader, isA9lh);
+            patchNativeFirm(firmVersion, nandType, emuHeader, isA9lh);
             break;
         case SAFE_FIRM:
             patchSafeFirm();
             break;
         default:
-            patchLegacyFirm(firmType);
+            //Skip patching on unsupported O3DS AGB/TWL FIRMs
+            if(isN3DS || firmVersion >= (firmType == TWL_FIRM ? 0x16 : 0xB)) patchLegacyFirm(firmType);
             break;
     }
 
@@ -242,29 +243,23 @@ void main(void)
     launchFirm(firmType, isFirmlaunch);
 }
 
-static inline void loadFirm(FirmwareType firmType, bool externalFirm)
+static inline u32 loadFirm(FirmwareType firmType)
 {
     section = firm->section;
 
-    bool externalFirmLoaded = externalFirm &&
+    //Load FIRM from CTRNAND, unless it's an O3DS and we're loading a pre-5.0 NATIVE FIRM
-                              fileRead(firm, "/luma/firmware.bin") &&
+    u32 firmVersion = firmRead(firm, (u32)firmType);
-                              (((u32)section[2].address >> 8) & 0xFF) == (isN3DS ? 0x60 : 0x68);
 
-    /* If the conditions to load the external FIRM aren't met, or reading fails, or the FIRM
+    if(!isN3DS && firmType == NATIVE_FIRM && firmVersion < 0x25)
-       doesn't match the console, load FIRM from CTRNAND */
-    if(!externalFirmLoaded)
     {
-        const char *firmFolders[4][2] = {{ "00000002", "20000002" },
+        if(!fileRead(firm, "/luma/firmware.bin") || (((u32)section[2].address >> 8) & 0xFF) == (isN3DS ? 0x60 : 0x68)) mcuReboot();
-                                         { "00000102", "20000102" },
-                                         { "00000202", "20000202" },
-                                         { "00000003", "20000003" }};
-
-        firmRead(firm, firmFolders[(u32)firmType][isN3DS ? 1 : 0]);
-        decryptExeFs((u8 *)firm);
     }
+    else decryptExeFs((u8 *)firm);
+
+    return firmVersion;
 }
 
-static inline void patchNativeFirm(FirmwareSource nandType, u32 emuHeader, bool isA9lh)
+static inline void patchNativeFirm(u32 firmVersion, FirmwareSource nandType, u32 emuHeader, bool isA9lh)
 {
     u8 *arm9Section = (u8 *)firm + section[2].offset;
 
@@ -275,8 +270,8 @@ static inline void patchNativeFirm(FirmwareSource nandType, u32 emuHeader, bool
         firm->arm9Entry = (u8 *)0x801B01C;
     }
 
-    //Sets the 7.x NCCH KeyX and the 6.x gamecard save data KeyY
+    //Sets the 7.x NCCH KeyX and the 6.x gamecard save data KeyY on >= 6.0 O3DS FIRMs, if not using A9LH
-    else if(!isA9lh) setRSAMod0DerivedKeys();
+    else if(!isA9lh && firmVersion >= 0x29) setRSAMod0DerivedKeys();
 
     //Find the Process9 .code location, size and memory address
     u32 process9Size,
@@ -299,12 +294,15 @@ static inline void patchNativeFirm(FirmwareSource nandType, u32 emuHeader, bool
     //Apply firmlaunch patches, not on 9.0 FIRM as it breaks firmlaunchhax
     patchFirmlaunches(process9Offset, process9Size, process9MemAddr);
 
-    //Apply anti-anti-DG patches for >= 11.0 firmwares
+    //11.0 FIRM patches
+    if(firmVersion >= (isN3DS ? 0x21 : 0x52))
+    {
+        //Apply anti-anti-DG patches
         patchTitleInstallMinVersionCheck(process9Offset, process9Size);
 
-    //Does nothing if svcBackdoor is still there
         reimplementSvcBackdoor((u8 *)firm + section[1].offset, section[1].size);
     }
+}
 
 static inline void patchLegacyFirm(FirmwareType firmType)
 {
@@ -315,7 +313,7 @@ static inline void patchLegacyFirm(FirmwareType firmType)
         firm->arm9Entry = (u8 *)0x801301C;
     }
 
-    applyLegacyFirmPatches((u8 *)firm, firmType, isN3DS);
+    applyLegacyFirmPatches((u8 *)firm, firmType);
 }
 
 static inline void patchSafeFirm(void)
@@ -369,12 +367,12 @@ static inline void launchFirm(FirmwareType firmType, bool isFirmlaunch)
         arm11 = (u32 *)0x1FFFFFF8;
     }
 
-    flushEntireDCache(); //Ensure that all memory transfers have completed and that the data cache has been flushed 
-    flushEntireICache();
-
     //Set ARM11 kernel entrypoint
     *arm11 = (u32)firm->arm11Entry;
 
+    flushEntireDCache(); //Ensure that all memory transfers have completed and that the data cache has been flushed 
+    flushEntireICache();
+
     //Final jump to ARM9 kernel
     ((void (*)())firm->arm9Entry)();
 }

source/firm.h

@@ -53,8 +53,8 @@ typedef enum ConfigurationStatus
     CREATE_CONFIGURATION = 2
 } ConfigurationStatus;
 
-static inline void loadFirm(FirmwareType firmType, bool externalFirm);
+static inline u32 loadFirm(FirmwareType firmType);
-static inline void patchNativeFirm(FirmwareSource nandType, u32 emuHeader, bool isA9lh);
+static inline void patchNativeFirm(u32 firmVersion, FirmwareSource nandType, u32 emuHeader, bool isA9lh);
 static inline void patchLegacyFirm(FirmwareType firmType);
 static inline void patchSafeFirm(void);
 static inline void copySection0AndInjectLoader(void);

source/fs.c

@@ -106,14 +106,20 @@ void loadPayload(u32 pressed)
 
         flushDCacheRange(loaderAddress, loader_size);
         flushICacheRange(loaderAddress, loader_size);
+
         ((void (*)())loaderAddress)();
     }
 }
 
-void firmRead(void *dest, const char *firmFolder)
+u32 firmRead(void *dest, u32 firmType)
 {
+    const char *firmFolders[4][2] = {{ "00000002", "20000002" },
+                                    { "00000102", "20000102" },
+                                    { "00000202", "20000202" },
+                                    { "00000003", "20000003" }};
+
     char path[48] = "1:/title/00040138/00000000/content";
-    memcpy(&path[18], firmFolder, 8);
+    memcpy(&path[18], firmFolders[firmType][isN3DS ? 1 : 0], 8);
 
     DIR dir;
     FILINFO info;
@@ -149,12 +155,16 @@ void firmRead(void *dest, const char *firmFolder)
     u32 i = 42;
 
     //Convert back the .app name from integer to array
-    while(id)
+    u32 tempId = id;
+
+    while(tempId)
     {
         static const char hexDigits[] = "0123456789ABCDEF";
-        path[i--] = hexDigits[id & 0xF];
+        path[i--] = hexDigits[tempId & 0xF];
-        id >>= 4;
+        tempId >>= 4;
     }
 
     fileRead(dest, path);
+
+    return id;
 }

source/fs.h

@@ -26,8 +26,10 @@
 
 #define PATTERN(a)      a "_*.bin"
 
+extern bool isN3DS;
+
 bool mountFs(void);
 u32 fileRead(void *dest, const char *path);
 void fileWrite(const void *buffer, const char *path, u32 size);
 void loadPayload(u32 pressed);
-void firmRead(void *dest, const char *firmFolder);
+u32 firmRead(void *dest, u32 firmType);

source/patches.c

@@ -119,8 +119,6 @@ void reimplementSvcBackdoor(u8 *pos, u32 size)
     u32 *svcTable = (u32 *)(pos + *(u32 *)(pos + 0xFFFF0008 - svcOffset - 0xFFF00000 + 8) - 0xFFF00000); //SVC handler address
     while(*svcTable) svcTable++; //Look for SVC0 (NULL)
 
-    if(!svcTable[0x7B])
-    {
     u32 *freeSpace;
     for(freeSpace = exceptionsPage; *freeSpace != 0xFFFFFFFF; freeSpace++);
 
@@ -128,7 +126,6 @@ void reimplementSvcBackdoor(u8 *pos, u32 size)
 
     svcTable[0x7B] = 0xFFFF0000 + ((u8 *)freeSpace - (u8 *)exceptionsPage);
 }
-}
 
 void patchTitleInstallMinVersionCheck(u8 *pos, u32 size)
 {
@@ -136,10 +133,10 @@ void patchTitleInstallMinVersionCheck(u8 *pos, u32 size)
     
     u8 *off = memsearch(pos, pattern, size, 4);
     
-    if(off != NULL) off[4] = 0xE0;
+    off[4] = 0xE0;
 }
 
-void applyLegacyFirmPatches(u8 *pos, FirmwareType firmType, bool isN3DS)
+void applyLegacyFirmPatches(u8 *pos, FirmwareType firmType)
 {
     const patchData twlPatches[] = {
         {{0x1650C0, 0x165D64}, {{ 6, 0x00, 0x20, 0x4E, 0xB0, 0x70, 0xBD }}, 0},

source/patches.h

@@ -33,6 +33,8 @@ typedef struct patchData {
     u32 type;
 } patchData;
 
+extern bool isN3DS;
+
 u8 *getProcess9(u8 *pos, u32 size, u32 *process9Size, u32 *process9MemAddr);
 void patchSignatureChecks(u8 *pos, u32 size);
 void patchTitleInstallMinVersionCheck(u8 *pos, u32 size);
@@ -40,5 +42,5 @@ void patchFirmlaunches(u8 *pos, u32 size, u32 process9MemAddr);
 void patchFirmWrites(u8 *pos, u32 size);
 void patchFirmWriteSafe(u8 *pos, u32 size);
 void reimplementSvcBackdoor(u8 *pos, u32 size);
-void applyLegacyFirmPatches(u8 *pos, FirmwareType firmType, bool isN3DS);
+void applyLegacyFirmPatches(u8 *pos, FirmwareType firmType);
 u32 getLoader(u8 *pos, u32 *loaderSize);