Frank Vannieuwkerke / FlashFileSystem

FLASH File System This file system can mount, read, and enumerate a file system image from Flash memory.

Fork of FlashFileSystem by Adam Green

A filesystem for accessing a read-only file system placed in the internal FLASH memory of the mbed board.
The file system to be mounted by this file system should be created through the use of the fsbld utility on the PC.
This fsbld.zip archive contains the sources for that utility.

As fsbld creates two output files (a binary and a header file), there are two ways to add the resulting file system image:

  1. Concatenate the binary file system to the end of the .bin file created by the mbed online compiler before uploading to the mbed device.
    On *nix this can be done with the cat command.
    For example: cat Test_LPC1768.bin FileImage.bin >/Volumes/MBED/test.bin
    On Windows this can be done with the copy command.
    For example: copy /b Test_LPC1768.bin + FileImage.bin e:\test.bin
  2. Import the header file into your project, include this file in your main file and add 'roFlashDrive' to the FlashfileSystem constructor call.
    eg : static FlashFileSystem flash("flash", roFlashDrive);

A third (optional) parameter in the FlashfileSystem constructor call allows you to specify the size of the FLASH (KB) on the device (default = 512). eg (for a KL25Z device) : static FlashFileSystem flash("flash", NULL, 128);
Note that in this example, the pointer to the header file has been omitted, so we need to append the binary file system ourselves (see above). When you include the binary file system header in your main file, you can also use the roFlashDrive pointer. eg (for a KL25Z device) : static FlashFileSystem flash("flash", roFlashDrive, 128);

NOTE
This file system is case-sensitive.
Calling fopen("/flash/INDEX.html") won't successfully open a file named index.html in the root directory of the flash file system.

Diff: FlashFileSystem.cpp

Revision:
2:ca35ecd2fae6
Parent:
1:a3cb118c4f6e
--- a/FlashFileSystem.cpp	Wed Aug 03 22:29:40 2011 +0000
+++ b/FlashFileSystem.cpp	Sun Apr 05 10:04:44 2015 +0000
@@ -402,12 +402,17 @@
    Parameters:
     pName is the root name to be used for this file system in fopen()
         pathnames.
+    pFlashDrive (optional) is a pointer to the read-only file system (const char array).
+        When pFlashDrive is not specified, it is up to the user to append the
+        read-only file system file to the compiled binary.
+    FlashSize (optional) is the size of the FLASH (KB) on the device to
+        search through for the file system signature (default = 512).
 */
-FlashFileSystem::FlashFileSystem(const char* pName) : FileSystemLike(pName)
+FlashFileSystem::FlashFileSystem(const char* pName, const uint8_t *pFlashDrive, const uint32_t FlashSize) : FileSystemLike(pName)
 {
     static const char   FileSystemSignature[] = FILE_SYSTEM_SIGNATURE;
     SFileSystemHeader*  pHeader = NULL;
-    char*               pCurr = (char*)FILE_SYSTEM_FLASH_SIZE - sizeof(pHeader->FileSystemSignature);
+    char*               pCurr = (char*)(FlashSize * 1024) - sizeof(pHeader->FileSystemSignature);
     
     // Initialize the members
     m_pFLASHBase = NULL;
@@ -417,18 +422,25 @@
     // Scan backwards through 512k FLASH looking for the file system signature
     // NOTE: The file system image should be located after this code itself
     //       so stop the search.
-    while (pCurr > FileSystemSignature)
+    if(pFlashDrive == NULL)
     {
-        if (0 == memcmp(pCurr, FileSystemSignature, sizeof(pHeader->FileSystemSignature)))
+        while (pCurr > FileSystemSignature)
         {
-            break;
+            if (0 == memcmp(pCurr, FileSystemSignature, sizeof(pHeader->FileSystemSignature)))
+            {
+                break;
+            }
+            pCurr--;
         }
-        pCurr--;
+        if (pCurr <= FileSystemSignature)
+        {
+            TRACE("FlashFileSystem: Failed to find file system image in ROM.\n");
+            return;
+        }
     }
-    if (pCurr <= FileSystemSignature)
+    else
     {
-        TRACE("FlashFileSystem: Failed to find file system image in RAM.\n");
-        return;
+        pCurr = (char *)pFlashDrive;
     }
     if (((unsigned int)pCurr & 0x3) != 0)
     {