diff --git a/arm9/source/fs.c b/arm9/source/fs.c
index 17a6b1b..300a59f 100644
--- a/arm9/source/fs.c
+++ b/arm9/source/fs.c
@@ -37,6 +37,8 @@
 #include "firm.h"
 #include "crypto.h"
 #include "strings.h"
+#include "alignedseqmemcpy.h"
+#include "i2c.h"
 
 static FATFS sdFs,
              nandFs;
@@ -121,6 +123,79 @@ bool fileDelete(const char *path)
     return f_unlink(path) == FR_OK;
 }
 
+bool fileCopy(const char *pathSrc, const char *pathDst, bool replace, void *tmpBuffer, size_t bufferSize)
+{
+    FIL fileSrc, fileDst;
+    FRESULT res;
+
+    res = f_open(&fileSrc, pathSrc, FA_READ);
+    if (res != FR_OK)
+        return true; // Succeed if the source file doesn't exist
+
+    size_t szSrc = f_size(&fileSrc), rem = szSrc;
+
+    res = f_open(&fileDst, pathDst, FA_WRITE | (replace ? FA_CREATE_ALWAYS : FA_CREATE_NEW));
+
+    if (res == FR_EXIST)
+    {
+        // We did not fail
+        f_close(&fileSrc);
+        return true;
+    }
+    else if (res == FR_NO_PATH)
+    {
+        const char *c;
+        for (c = pathDst + strlen(pathDst); *c != '/' && c >= pathDst; --c);
+        if (c >= pathDst && c - pathDst <= FF_MAX_LFN && *c != '\0')
+        {
+            char path[FF_MAX_LFN + 1];
+            strncpy(path, pathDst, c - pathDst);
+            path[FF_MAX_LFN] = '\0';
+            res = f_mkdir(path);
+        }
+
+        if (res == FR_OK)
+            res = f_open(&fileDst, pathDst, FA_WRITE | (replace ? FA_CREATE_ALWAYS : FA_CREATE_NEW));
+    }
+
+    if (res != FR_OK)
+    {
+        f_close(&fileSrc);
+        return false;
+    }
+
+    while (rem > 0)
+    {
+        size_t sz = rem >= bufferSize ? bufferSize : rem;
+        UINT n = 0;
+
+        res = f_read(&fileSrc, tmpBuffer, sz, &n);
+        if (n != sz)
+            res = FR_INT_ERR; // should not happen
+        
+        if (res == FR_OK)
+        {
+            res = f_write(&fileDst, tmpBuffer, sz, &n);
+            if (n != sz)
+                res = FR_DENIED; // disk full
+        }
+
+        if (res != FR_OK)
+        {
+            f_close(&fileSrc);
+            f_close(&fileDst);
+            f_unlink(pathDst); // oops, failed
+            return false;
+        }
+        rem -= sz;
+    }
+
+    f_close(&fileSrc);
+    f_close(&fileDst);
+
+    return true;
+}
+
 bool findPayload(char *path, u32 pressed)
 {
     const char *pattern;
@@ -309,3 +384,39 @@ void findDumpFile(const char *folderPath, char *fileName)
 
     if(result == FR_OK) f_closedir(&dir);
 }
+
+static u8 fileCopyBuffer[0x1000];
+bool backupEssentialFiles(void)
+{
+    size_t sz = sizeof(fileCopyBuffer);
+
+    bool ok = !(isSdMode && !mountFs(false, false));
+
+    ok = ok && fileCopy("1:/ro/sys/HWCAL0.dat", "backups/HWCAL0.dat", false, fileCopyBuffer, sz);
+    ok = ok && fileCopy("1:/ro/sys/HWCAL1.dat", "backups/HWCAL1.dat", false, fileCopyBuffer, sz);
+
+    ok = ok && fileCopy("1:/rw/sys/LocalFriendCodeSeed_A", "backups/LocalFriendCodeSeed_A", false, fileCopyBuffer, sz); // often doesn't exist
+    ok = ok && fileCopy("1:/rw/sys/LocalFriendCodeSeed_B", "backups/LocalFriendCodeSeed_B", false, fileCopyBuffer, sz);
+
+    ok = ok && fileCopy("1:/rw/sys/SecureInfo_A", "backups/SecureInfo_A", false, fileCopyBuffer, sz);
+    ok = ok && fileCopy("1:/rw/sys/SecureInfo_B", "backups/SecureInfo_B", false, fileCopyBuffer, sz); // often doesn't exist
+
+    if (!ok) return false;
+
+    alignedseqmemcpy(fileCopyBuffer, (const void *)0x10012000, 0x100);
+    if (getFileSize("backups/otp.bin") != 0x100)
+        ok = ok && fileWrite(fileCopyBuffer, "backups/otp.bin", 0x100);
+
+    if (!ok) return false;
+
+    // On dev boards, but not O3DS IS_DEBUGGER, hwcal is on an EEPROM chip accessed via I2C
+    u8 c = mcuConsoleInfo[0];
+    if (c == 2 || c == 4 || (ISN3DS && c == 5) || c == 6)
+    {
+        I2C_readRegBuf(I2C_DEV_EEPROM, 0, fileCopyBuffer, 0x1000); // Up to two instances of hwcal, with the second one @0x800
+        if (getFileSize("backups/HWCAL_01_EEPROM.dat") != 0x1000)
+            ok = ok && fileWrite(fileCopyBuffer, "backups/HWCAL_01_EEPROM.dat", 0x1000);
+    }
+
+    return ok;
+}
diff --git a/arm9/source/fs.h b/arm9/source/fs.h
index db83b2a..99c5a9c 100644
--- a/arm9/source/fs.h
+++ b/arm9/source/fs.h
@@ -35,7 +35,10 @@ u32 fileRead(void *dest, const char *path, u32 maxSize);
 u32 getFileSize(const char *path);
 bool fileWrite(const void *buffer, const char *path, u32 size);
 bool fileDelete(const char *path);
+bool fileCopy(const char *pathSrc, const char *pathDst, bool replace, void *tmpBuffer, size_t bufferSize);
 bool findPayload(char *path, u32 pressed);
 bool payloadMenu(char *path, bool *hasDisplayedMenu);
 u32 firmRead(void *dest, u32 firmType);
 void findDumpFile(const char *folderPath, char *fileName);
+
+bool backupEssentialFiles(void);
diff --git a/arm9/source/main.c b/arm9/source/main.c
index 50b6666..927cacb 100644
--- a/arm9/source/main.c
+++ b/arm9/source/main.c
@@ -49,6 +49,9 @@ bool isSdMode;
 u16 launchedPath[80+1];
 BootType bootType;
 
+u16 mcuFwVersion;
+u8 mcuConsoleInfo[9];
+
 void main(int argc, char **argv, u32 magicWord)
 {
     bool isFirmProtEnabled,
@@ -117,6 +120,11 @@ void main(int argc, char **argv, u32 magicWord)
     memcpy(__itcm_start__, __itcm_lma__, __itcm_bss_start__ - __itcm_start__);
     memset(__itcm_bss_start__, 0, __itcm_end__ - __itcm_bss_start__);
     I2C_init();
+
+    I2C_readRegBuf(I2C_DEV_MCU, 0x00, (u8 *)&mcuFwVersion, 2);
+    if ((mcuFwVersion & 0xFFF) < 0x0100) error("Unsupported MCU FW version.");
+    I2C_readRegBuf(I2C_DEV_MCU, 0x7F, mcuConsoleInfo, 9);
+
     if(isInvalidLoader) error("Launched using an unsupported loader.");
 
     installArm9Handlers();
diff --git a/arm9/source/types.h b/arm9/source/types.h
index e4646bb..871bb45 100644
--- a/arm9/source/types.h
+++ b/arm9/source/types.h
@@ -130,3 +130,6 @@ extern BootType bootType;
 
 extern u16 launchedFirmTidLow[8];
 extern u16 launchedPath[80+1];
+
+extern u16 mcuFwVersion;
+extern u8 mcuConsoleInfo[9];