From 3c7ad93d1c9b0aa9111f05dad8b62ee868214aa7 Mon Sep 17 00:00:00 2001
From: windows-server-2003 <rin2004@softbank.ne.jp>
Date: Tue, 27 Feb 2018 16:53:45 +0900
Subject: [PATCH] Forbid writing to SD if write locked

---
 arm9/source/filesys/fsperm.c | 7 +++++++
 arm9/source/filesys/fsutil.c | 6 ++++++
 arm9/source/nand/sdmmc.h     | 2 ++
 3 files changed, 15 insertions(+)

diff --git a/arm9/source/filesys/fsperm.c b/arm9/source/filesys/fsperm.c
index dad27a8..3f20ae8 100644
--- a/arm9/source/filesys/fsperm.c
+++ b/arm9/source/filesys/fsperm.c
@@ -4,6 +4,7 @@
 #include "image.h"
 #include "unittype.h"
 #include "ui.h"
+#include "sdmmc.h"
 
 #define PATH_SYS_LVL1   "S:/twln.bin", "S:/twlp.bin" 
 #define PATH_SYS_LVL2   "1:/rw/sys/LocalFriendCodeSeed_B", "1:/rw/sys/LocalFriendCodeSeed_A", \
@@ -26,6 +27,12 @@ bool CheckWritePermissions(const char* path) {
     if ((drvtype & DRV_IMAGE) && !CheckWritePermissions(GetMountPath()))
         return false; // endless loop when mounted file inside image, but not possible
     
+    // SD card write protection check
+    if ((drvtype & (DRV_SDCARD | DRV_EMUNAND | DRV_ALIAS)) && SD_WRITE_PROTECTED) {
+        ShowPrompt(false, "SD card is write protected!\nCan't continue.");
+        return false;
+    }
+    
     // check drive type, get permission type
     if (drvtype & DRV_SYSNAND) {
         u32 perms[] = { PERM_SYS_LVL0, PERM_SYS_LVL1, PERM_SYS_LVL2, PERM_SYS_LVL3 };
diff --git a/arm9/source/filesys/fsutil.c b/arm9/source/filesys/fsutil.c
index e75537e..9296449 100644
--- a/arm9/source/filesys/fsutil.c
+++ b/arm9/source/filesys/fsutil.c
@@ -49,6 +49,12 @@ bool FormatSDCard(u64 hidden_mb, u32 cluster_size, const char* label) {
         return false;
     }
     
+    // Write protection check
+    if (SD_WRITE_PROTECTED) {
+        ShowPrompt(false, "SD card is write protected!\nCan't continue.");
+        return false;
+    }
+    
     // build the MBR
     memcpy(mbrdata + 0x08, &fat_sector, 4);
     memcpy(mbrdata + 0x0C, &fat_size, 4);
diff --git a/arm9/source/nand/sdmmc.h b/arm9/source/nand/sdmmc.h
index 5195cc0..3f62092 100644
--- a/arm9/source/nand/sdmmc.h
+++ b/arm9/source/nand/sdmmc.h
@@ -74,6 +74,8 @@
 #define TMIO_MASK_READOP  (TMIO_STAT1_RXRDY | TMIO_STAT1_DATAEND)
 #define TMIO_MASK_WRITEOP (TMIO_STAT1_TXRQ | TMIO_STAT1_DATAEND)
 
+#define SD_WRITE_PROTECTED (!((*(volatile u16*) (SDMMC_BASE + 0x1C)) & (0x1 << 7)))
+
 typedef struct mmcdevice {
     u8 *rData;
     const u8 *tData;