Enable support for reading FIRM system modules from SD card (in /luma/sysmodules)

source/firm.c

@@ -378,6 +378,7 @@ static inline void patchSafeFirm(void)
 
         patchFirmWrites(arm9Section, section[2].size);
     }
+    else patchFirmWriteSafe(arm9Section, section[2].size);
     
     if(DEVMODE)
     {
@@ -385,20 +386,70 @@ static inline void patchSafeFirm(void)
         patchExceptionHandlersInstall(arm9Section, section[2].size);
         patchSvcBreak9(arm9Section, section[2].size, (u32)(section[2].address));
     }
-    
-    else patchFirmWriteSafe(arm9Section, section[2].size);
 }
 
-static inline void copySection0AndInjectLoader(void)
+static inline void copySection0AndInjectSystemModules(void)
 {
     u8 *arm11Section0 = (u8 *)firm + section[0].offset;
+    char fileName[] = "/luma/sysmodules/--------.cxi";
+    const char *ext = ".cxi";
 
-    u32 loaderSize;
+    struct
-    u32 loaderOffset = getLoader(arm11Section0, &loaderSize);
+    {
+        u32 size;
+        char name[8];
+        const u8 *addr;
+    } modules[5] = {{0}};
 
-    memcpy(section[0].address, arm11Section0, loaderOffset);
+    u8 *pos = arm11Section0;
-    memcpy(section[0].address + loaderOffset, injector, injector_size);
+    u32 loaderIndex = 0;
-    memcpy(section[0].address + loaderOffset + injector_size, arm11Section0 + loaderOffset + loaderSize, section[0].size - (loaderOffset + loaderSize));
+    for(u32 i = 0; i < 5; i++)
+    {
+        modules[i].addr = pos;
+        modules[i].size = *(u32 *)(pos + 0x104) * 0x200;
+        
+        memcpy(modules[i].name, pos + 0x200, 8);
+        pos += modules[i].size;
+        
+        //Read modules from files if they exist
+        u32 nameOff;
+        for(nameOff = 0; nameOff < 8 && modules[i].name[nameOff] != 0; nameOff++);
+        memcpy(fileName + 17, modules[i].name, nameOff);
+        memcpy(fileName + 17 + nameOff, ext, 5);
+        
+        u32 fileSize = getFileSize(fileName);
+        if(fileSize != 0)
+        {
+            modules[i].addr = NULL;
+            modules[i].size = fileSize;
+        }
+
+        if(memcmp(modules[i].name, "loader", 7) == 0) loaderIndex = i;
+    }
+
+    if(modules[loaderIndex].addr != NULL)
+    {
+        modules[loaderIndex].size = injector_size;
+        modules[loaderIndex].addr = injector;
+    }
+
+    pos = section[0].address;
+    for(u32 i = 0; i < 5; i++)
+    {
+        if(modules[i].addr != NULL)
+            memcpy(pos, modules[i].addr, modules[i].size);
+        else
+        {
+             //Read modules from files if they exist
+            u32 nameOff;
+            for(nameOff = 0; nameOff < 8 && modules[i].name[nameOff] != 0; nameOff++);
+            memcpy(fileName + 17, modules[i].name, nameOff);
+            memcpy(fileName + 17 + nameOff, ext, 5);
+            fileRead(pos, fileName);
+        }
+
+        pos += modules[i].size;
+    }
 }
 
 static inline void launchFirm(FirmwareType firmType, u32 isFirmlaunch)
@@ -407,7 +458,7 @@ static inline void launchFirm(FirmwareType firmType, u32 isFirmlaunch)
     u32 sectionNum;
     if(firmType == NATIVE_FIRM)
     {
-        copySection0AndInjectLoader();
+        copySection0AndInjectSystemModules();
         sectionNum = 1;
     }
     else sectionNum = 0;

source/firm.h

@@ -46,5 +46,5 @@ static inline void loadFirm(FirmwareType firmType, u32 externalFirm);
 static inline void patchNativeFirm(FirmwareSource nandType, u32 emuHeader, A9LHMode a9lhMode);
 static inline void patchLegacyFirm(FirmwareType firmType);
 static inline void patchSafeFirm(void);
-static inline void copySection0AndInjectLoader(void);
+static inline void copySection0AndInjectSystemModules(void);
 static inline void launchFirm(FirmwareType firmType, u32 isFirmlaunch);

source/fs.c

@@ -30,6 +30,7 @@ u32 fileRead(void *dest, const char *path)
     {
         unsigned int read;
         size = f_size(&file);
+        if(dest == NULL) return size;
         f_read(&file, dest, size, &read);
         f_close(&file);
     }
@@ -38,6 +39,11 @@ u32 fileRead(void *dest, const char *path)
     return size;
 }
 
+u32 getFileSize(const char *path)
+{
+    return fileRead(NULL, path);
+}
+
 void fileWrite(const void *buffer, const char *path, u32 size)
 {
     FIL file;

source/fs.h

@@ -9,6 +9,7 @@
 #define PATTERN(a)      a "_*.bin"
 
 u32 mountFs(void);
+u32 getFileSize(const char *path);
 u32 fileRead(void *dest, const char *path);
 void fileWrite(const void *buffer, const char *path, u32 size);
 void findDumpFile(const char *path, char *fileName);

source/patches.c

@@ -264,21 +264,4 @@ void applyLegacyFirmPatches(u8 *pos, FirmwareType firmType, u32 isN3DS)
                 break;
         }
     }
-}
-
-u32 getLoader(u8 *pos, u32 *loaderSize)
-{
-    u8 *off = pos;
-    u32 size;
-
-    while(1)
-    {
-        size = *(u32 *)(off + 0x104) * 0x200;
-        if(*(u32 *)(off + 0x200) == 0x64616F6C) break;
-        off += size;
-    }
-
-    *loaderSize = size;
-
-    return (u32)(off - pos);
 }

source/patches.h

@@ -29,5 +29,4 @@ void patchUnitInfoValueSet(u8 *pos, u32 size);
 void patchKernelFCRAMAndVRAMMappingPermissions(u8 *pos, u32 size);
 void reimplementSvcBackdoor(u8 *pos, u32 size);
 void applyLegacyFirmPatches(u8 *pos, FirmwareType firmType, u32 isN3DS);
-u32 getLoader(u8 *pos, u32 *loaderSize);
 u8 *getUnitInfoValueSet(u8 *pos, u32 size);