Adam Green / FlashFileSystem

A file system which can mount, read, and enumerate a file system image which has been appended to the compiled .bin code file before being uploaded to the mbed device.

FLASH File System

This file system can mount, read, and enumerate a file system image which has been appended to the compiled .bin code file before being uploaded to the mbed device. I wrote a utility called fsbld to create images that can be used with this file system. This GitHub repository contains the sources for that utility.

To get the file system image onto the mbed device, you need to concatenate your binary from the compiler with the file system image binary.

  • 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 Test_LPC1768.bin + FileImage.bin e:\test.bin

Files at this revision

API Documentation at this revision

Revision 2:ca35ecd2fae6, committed 2015-04-05

Comitter:
frankvnk
Date:
Sun Apr 05 10:04:44 2015 +0000
Parent:
1:a3cb118c4f6e
Commit message:
2 options added: The ability to include a header file containing the binary file system image built with fsbld and the ability to set the system flash size.

Changed in this revision

FlashFileSystem.cpp Show annotated file Show diff for this revision Revisions of this file
FlashFileSystem.h Show annotated file Show diff for this revision Revisions of this file
ffsformat.h Show annotated file Show diff for this revision Revisions of this file 
diff -r a3cb118c4f6e -r ca35ecd2fae6 FlashFileSystem.cpp
--- 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)
     {

diff -r a3cb118c4f6e -r ca35ecd2fae6 FlashFileSystem.h
--- a/FlashFileSystem.h	Wed Aug 03 22:29:40 2011 +0000
+++ b/FlashFileSystem.h	Sun Apr 05 10:04:44 2015 +0000
@@ -121,22 +121,40 @@
 
 
 
-/** A filesystem for accessing a read-only file system placed in the internal
- *  FLASH memory of the NXP chip on the mbed board.
+/** A filesystem for accessing a read-only file system placed in the internal\n
+ *  FLASH memory of the mbed board.
+ *\n
+ *  The file system to be mounted by this file system should be created through\n
+ *  the use of the fsbld utility on the PC.\n
+ *\n
+ *  As fsbld creates two output files (a binary and a header file), there are two\n
+ *  ways to add the resulting file system image:\n
+ *  -# Concatenate the binary file system to the end of the .bin file created\n
+ *     by the mbed online compiler before uploading to the mbed device.\n
+ *  -# Import the header file into your project, include this file in your main\n
+ *     file and add 'roFlashDrive' to the FlashfileSystem constructor call.\n
+ *     eg : static FlashFileSystem flash("flash", roFlashDrive);\n
  *
- *  The file system to be mounted by this file system should be created through
- *  the use of the fsbld utility on the PC and the resulting file system image
- *  concatentated to the end of the .bin file created by the mbed online
- *  compiler before uploading to the mbed device.
- *
- *  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.
+ *  A third (optional) parameter in the FlashfileSystem constructor call allows\n
+ *  you to specify the size of the FLASH (KB) on the device (default = 512).\n
+ *  eg (for a KL25Z device) : static FlashFileSystem flash("flash", NULL, 128);\n
+ *  Note that in this example, the pointer to the header file has been omitted,\n
+ *  so we need to append the binary file system ourselves (see above).\n
+ *  When you use the binary file system header in your main file, you can\n
+ *  use the roFlashDrive pointer.\n
+ *  eg (for a KL25Z device) : static FlashFileSystem flash("flash", roFlashDrive, 128);\n
+ *\n
+ *  NOTE: This file system is case-sensitive.  Calling fopen("/flash/INDEX.html")\n
+ *        won't successfully open a file named index.html in the root directory\n
+ *        of the flash file system.\n
  *
  * Example:
  * @code
 #include <mbed.h>
 #include "FlashFileSystem.h"
+// Uncomment the line below when you imported the header file built with fsbld
+// and replace <Flashdrive> with its correct filename
+//#include "<FlashDrive>.h"
 
 static void _RecursiveDir(const char* pDirectoryName, DIR* pDirectory = NULL)
 {
@@ -210,7 +228,11 @@
     char               Buffer[128];
 
     // Create the file system under the name "flash".
+    // NOTE : When you include the the header file built with fsbld,
+    //        disable the first static FlashFileSystem... line
+    //        and enable the second static FlashFileSystem... line.
     static FlashFileSystem flash("flash");
+//    static FlashFileSystem flash("flash, roFlashDrive");
     if (!flash.IsMounted())
     {
         error("Failed to mount FlashFileSystem.\r\n");
@@ -261,7 +283,7 @@
 class FlashFileSystem : public FileSystemLike 
 {
 public:
-    FlashFileSystem(const char* pName);
+    FlashFileSystem(const char* pName, const uint8_t *pFlashDrive = NULL, const uint32_t FlashSize = 512);
     
     virtual FileHandle* open(const char* pFilename, int Flags);
     virtual DirHandle*  opendir(const char *pDirectoryName);

diff -r a3cb118c4f6e -r ca35ecd2fae6 ffsformat.h
--- a/ffsformat.h	Wed Aug 03 22:29:40 2011 +0000
+++ b/ffsformat.h	Sun Apr 05 10:04:44 2015 +0000
@@ -24,11 +24,6 @@
    Only the first 8 bytes are used and the NULL terminator discarded. */
 #define FILE_SYSTEM_SIGNATURE "FFileSys"
 
-/* The size of the FLASH on the device to search through for the file
-   system signature. */
-#define FILE_SYSTEM_FLASH_SIZE  (512 * 1024)
-
-
 /* Header stored at the beginning of the file system image. */
 typedef struct _SFileSystemHeader
 {