That was a silly mistake (Fixed -102)

Author: Naim2000

source/fatfs/ffconf.h

@@ -84,7 +84,7 @@
 / Locale and Namespace Configurations
 /---------------------------------------------------------------------------*/
 
-#define FF_CODE_PAGE	932
+#define FF_CODE_PAGE	437
 /* This option specifies the OEM code page to be used on the target system.
 /  Incorrect code page setting can cause a file open failure.
 /

source/fs.c

@@ -38,7 +38,7 @@ int NAND_GetFileSize(const char* filepath, size_t* size) {
 	if (size)
 		*size = 0;
 
-	int fd = ISFS_Open(filepath, 0);
+	int fd = ISFS_Open(filepath, ISFS_OPEN_READ);
 	if (fd < 0)
 		return fd;