diff --git a/source/fatfs/ffconf.h b/source/fatfs/ffconf.h
index d4c0ea6..830daac 100644
--- a/source/fatfs/ffconf.h
+++ b/source/fatfs/ffconf.h
@@ -55,7 +55,7 @@
 /* This option switches fast seek feature. (0:Disable or 1:Enable) */
 
 
-#define _USE_LABEL		0
+#define _USE_LABEL		1
 /* This option switches volume label functions, f_getlabel() and f_setlabel().
 /  (0:Disable or 1:Enable) */
 
@@ -154,7 +154,7 @@
 /  the drive ID strings are: A-Z and 0-9. */
 
 
-#define	_MULTI_PARTITION	0
+#define	_MULTI_PARTITION	1
 /* This option switches multi-partition feature. By default (0), each logical drive
 /  number is bound to the same physical drive number and only an FAT volume found on
 /  the physical drive will be mounted. When multi-partition feature is enabled (1),
diff --git a/source/fs.c b/source/fs.c
index ca7216e..15250e0 100644
--- a/source/fs.c
+++ b/source/fs.c
@@ -3,6 +3,7 @@
 #include "virtual.h"
 #include "image.h"
 #include "sha.h"
+#include "sdmmc.h"
 #include "ff.h"
 
 #define MAIN_BUFFER ((u8*)0x21200000)
@@ -11,6 +12,12 @@
 #define NORM_FS  10
 #define VIRT_FS  4
 
+// Volume2Partition resolution table
+PARTITION VolToPart[] = {
+    {0, 1}, {1, 0}, {2, 0}, {3, 0}, {4, 0},
+    {5, 0}, {6, 0}, {7, 0}, {8, 0}, {9, 0}
+};
+
 // don't use this area for anything else!
 static FATFS* fs = (FATFS*)0x20316000; 
 
@@ -78,6 +85,63 @@ bool IsMountedFS(const char* path) {
     return ((fsnum >= 0) && (fsnum < NORM_FS)) ? fs_mounted[fsnum] : false;
 }
 
+uint64_t GetSDCardSize() {
+    if (sdmmc_sdcard_init() != 0) return 0;
+    return (u64) getMMCDevice(1)->total_size * 512;
+}
+
+bool FormatSDCard(u32 hidden_mb) {
+    u8 mbr[0x200] = { 0 };
+    u8 mbrdata[0x42] = {
+        0x80, 0x01, 0x01, 0x00, 0x0C, 0xFE, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x80, 0x01, 0x01, 0x00, 0x1C, 0xFE, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x55, 0xAA
+    };
+    u32 sd_size = getMMCDevice(1)->total_size;
+    u32* fat_sector = (u32*) (mbrdata + 0x08);
+    u32* fat_size   = (u32*) (mbrdata + 0x0C);
+    u32* emu_sector = (u32*) (mbrdata + 0x18);
+    u32* emu_size   = (u32*) (mbrdata + 0x1C);
+    
+    *emu_sector = 1;
+    *emu_size = hidden_mb * (1024 * 1024) / 512;
+    *fat_sector = align(*emu_sector + *emu_size, 0x2000); // align to 4MB
+    if (sd_size < *fat_sector + 0x80000) { // minimum free space: 256MB
+        ShowPrompt(false, "ERROR: SD card is too small");
+        return false;
+    }
+    *fat_size = sd_size - *fat_sector;
+    sd_size = *fat_size;
+    
+    // build the MBR
+    memcpy(mbr + 0x1BE, mbrdata, 0x42);
+    if (hidden_mb) memcpy(mbr, "GATEWAYNAND", 12);
+    else memset(mbr + 0x1CE, 0, 0x10);
+    
+    // one last warning....
+    if (!ShowUnlockSequence(3, "!WARNING!\n \nProceeding will format this SD.\nThis will irreversibly delete\nALL data on it.\n"))
+        return false;
+    ShowString("Formatting SD, please wait...", hidden_mb); 
+    
+    // write the MBR to disk
+    // !this assumes a fully deinitialized file system!
+    if ((sdmmc_sdcard_init() != 0) || (sdmmc_sdcard_writesectors(0, 1, mbr) != 0)) {
+        ShowPrompt(false, "ERROR: SD card i/o failure");
+        return false;
+    }
+    
+    // format the SD card
+    // cluster size: auto (<= 4GB) / 32KiB (<= 8GB) / 64 KiB (> 8GB)
+    InitSDCardFS();
+    UINT c_size = (sd_size < 0x800000) ? 0 : (sd_size < 0x1000000) ? 32768 : 65536;
+    bool ret = (f_mkfs("0:", 0, c_size) == FR_OK) && (f_setlabel("0:GM9SD") == FR_OK);
+    DeinitSDCardFS();
+    
+    return ret;
+}
+
 bool CheckWritePermissions(const char* path) {
     char area_name[16];
     int pdrv = PathToNumFS(path);
diff --git a/source/fs.h b/source/fs.h
index 18217ea..8dd26cc 100644
--- a/source/fs.h
+++ b/source/fs.h
@@ -39,6 +39,12 @@ bool InitExtFS();
 void DeinitExtFS();
 void DeinitSDCardFS();
 
+/** Return total size of SD card **/
+uint64_t GetSDCardSize();
+
+/** Format the SD card **/
+bool FormatSDCard(u32 hidden_mb);
+
 /** Check if writing to this path is allowed **/
 bool CheckWritePermissions(const char* path);
 
diff --git a/source/godmode.c b/source/godmode.c
index 1ff8b58..d615cc5 100644
--- a/source/godmode.c
+++ b/source/godmode.c
@@ -7,7 +7,7 @@
 #include "virtual.h"
 #include "image.h"
 
-#define VERSION "0.5.8"
+#define VERSION "0.5.9"
 
 #define N_PANES 2
 #define IMG_DRV "789I"
@@ -166,6 +166,36 @@ void DrawDirContents(DirStruct* contents, u32 cursor, u32* scroll) {
     } else DrawRectangle(BOT_SCREEN, SCREEN_WIDTH_BOT - bar_width, 0, bar_width, SCREEN_HEIGHT, COLOR_STD_BG);
 }
 
+u32 SdFormatMenu(void) {
+    const u32 emunand_size_table[6] = { 0x0, 0x0, 0x3AF, 0x4D8, 0x400, 0x800 };
+    const char* optionstr[6] = { "No EmuNAND", "O3DS NAND size", "N3DS NAND size", "1GB (legacy size)", "2GB (legacy size)", "User input..." };
+    u64 sdcard_size_mb = 0;
+    u64 emunand_size_mb = (u64) -1;
+    
+    // check actual SD card size
+    sdcard_size_mb = GetSDCardSize() / 0x100000;
+    if (!sdcard_size_mb) {
+        ShowPrompt(false, "ERROR: SD card not detected.");
+        return 1;
+    }
+    
+    u32 user_select = ShowSelectPrompt(6, optionstr, "Format SD card (%lluGB)?\nChoose EmuNAND size:", sdcard_size_mb / 1024);
+    if (user_select && (user_select < 6)) {
+        emunand_size_mb = emunand_size_table[user_select];
+    } else if (user_select == 6) do {
+        emunand_size_mb = ShowNumberPrompt(0, "SD card size is %lluMB.\nEnter EmuNAND size (MB) below:", sdcard_size_mb);
+        if (emunand_size_mb == (u64) -1) break;
+    } while (emunand_size_mb > sdcard_size_mb);
+    if (emunand_size_mb == (u64) -1) return 1;
+    
+    if (!FormatSDCard((u32) emunand_size_mb)) {
+        ShowPrompt(false, "Format SD: failed!");
+        return 1;
+    }
+    
+    return 0;
+}
+
 u32 HexViewer(const char* path) {
     static const u32 max_data = (SCREEN_HEIGHT / 8) * 16;
     static u32 mode = 0;
@@ -588,11 +618,17 @@ u32 GodMode() {
             DeinitSDCardFS();
             clipboard->n_entries = 0;
             memset(panedata, 0x00, N_PANES * sizeof(PaneData));
-            ShowPrompt(false, "SD card unmounted, you can eject now.\nPut it back in before you press <A>.");
-            while (!InitSDCardFS()) {
-                if (!ShowPrompt(true, "Reinitialising SD card failed! Retry?"))
-                    return exit_mode;
+            ShowString("SD card unmounted, you can eject now.\n \n<R+Y+\x1B> for format menu\n<A> to remount SD card");
+            while (true) {
+                u32 pad_choice = InputWait();
+                if ((pad_choice & (BUTTON_R1|BUTTON_Y|BUTTON_LEFT)) == (BUTTON_R1|BUTTON_Y|BUTTON_LEFT))
+                    SdFormatMenu();
+                else if (pad_choice & (BUTTON_B|BUTTON_START)) return exit_mode;
+                else if (!(pad_choice & BUTTON_A)) continue;
+                if (InitSDCardFS()) break;
+                ShowString("Reinitialising SD card failed!\n \n<R+Y+\x1B> for format menu\n<A> to retry, <B> to reboot");
             }
+            ClearScreenF(true, false, COLOR_STD_BG);
             InitEmuNandBase();
             InitExtFS();
             GetDirContents(current_dir, current_path);
diff --git a/source/ui.c b/source/ui.c
index 5a50582..7f4b21b 100644
--- a/source/ui.c
+++ b/source/ui.c
@@ -469,6 +469,23 @@ u64 ShowHexPrompt(u64 start_val, u32 n_digits, const char *format, ...) {
     return ret; 
 }
 
+u64 ShowNumberPrompt(u64 start_val, const char *format, ...) {
+    const char* alphabet = "0123456789";
+    char inputstr[20 + 1] = { 0 };
+    u64 ret = 0;
+    va_list va;
+    
+    snprintf(inputstr, 20 + 1, "%llu", start_val);
+    
+    va_start(va, format);
+    if (ShowInputPrompt(inputstr, 20 + 1, 1, alphabet, format, va)) {
+        sscanf(inputstr, "%llu", &ret);
+    } else ret = (u64) -1;
+    va_end(va);
+    
+    return ret; 
+}
+
 bool ShowDataPrompt(u8* data, u32* size, const char *format, ...) {
     const char* alphabet = "0123456789ABCDEF";
     char inputstr[128 + 1] = { 0 }; // maximum size of data: 64 byte
diff --git a/source/ui.h b/source/ui.h
index 21f2e2b..ca1dc97 100644
--- a/source/ui.h
+++ b/source/ui.h
@@ -73,5 +73,6 @@ bool ShowUnlockSequence(u32 seqlvl, const char *format, ...);
 u32 ShowSelectPrompt(u32 n, const char** options, const char *format, ...);
 bool ShowStringPrompt(char* inputstr, u32 max_size, const char *format, ...);
 u64 ShowHexPrompt(u64 start_val, u32 n_digits, const char *format, ...);
+u64 ShowNumberPrompt(u64 start_val, const char *format, ...);
 bool ShowDataPrompt(u8* data, u32* size, const char *format, ...);
 bool ShowProgress(u64 current, u64 total, const char* opstr);