Software Update via Ethernet - the mbed application can pull down an updated application binary from a web server and activate that binary. This library works only with the LPC1768, as it relies on the magic-chip boot-loader mechanism.

Dependents:   WattEye X10Svr PUB_SWUpdate

Success!! With this library, a network connection, and a web server hosting a new binary image, you can update the mbed firmware over the air (FOTA) - well, at least via Ethernet so far.

As of March 2015, it has been tested with the following mbed official libraries:

And a custom derivation:

  • HTTPClient v33, v32, which includes a custom HTTPFile.

Part of the update process involves checking the integrity of the downloaded binary file, for both a checksum and the program (file) size. To create this additional information, a small perl script is used (the important part is only 20 lines of code). See the documentation in the header file.

After the new binary is successfully downloaded, the checksum and the size are evaluated and if correct, then the old binary file is removed (this is the only way to cause the new binary to activate).

The mbed can then be automatically reset to activate the new image, or this may be deferred in case there is some other process necessary for an orderly restart.

Details are in the SWUpdate header file, and PUB_SWUpdate is a publicly accessible demonstration program for this library.

Revision:
9:73067ef14c30
Parent:
8:8e840a036116
Child:
14:0e012d53c6df
--- a/SWUpdate.cpp	Sun Jun 15 20:01:58 2014 +0000
+++ b/SWUpdate.cpp	Sat Jun 21 19:13:30 2014 +0000
@@ -30,6 +30,7 @@
     int newCksum = 0;
     int newFSize = 0;
     FILE *fh = fopen(fname, "rb");
+    
     INFO("IntegrityCheck(%s,%d,%d)", fname, cksum, fsize);
     if (fh) {
         char buf;
@@ -47,17 +48,96 @@
     return res;
 }
 
-bool SoftwareUpdate(const char *url, const char * name, Reboot_T reboot) {
+/// mytolower exists because not all compiler libraries have this function
+///
+/// This takes a character and if it is upper-case, it converts it to
+/// lower-case and returns it.
+///
+/// @param a is the character to convert
+/// @returns the lower case equivalent to a
+///
+static char mytolower(char a) {
+    if (a >= 'A' && a <= 'Z')
+        return (a - 'A' + 'a');
+    else
+        return a;
+}
+
+/// mystrnicmp exists because not all compiler libraries have this function.
+///
+/// Some have strnicmp, others _strnicmp, and others have C++ methods, which
+/// is outside the scope of this C-portable set of functions.
+///
+/// @param l is a pointer to the string on the left
+/// @param r is a pointer to the string on the right
+/// @param n is the number of characters to compare
+/// @returns -1 if l < r
+/// @returns 0 if l == r
+/// @returns +1 if l > r
+///
+static int mystrnicmp(const char *l, const char *r, size_t n) {
+    int result = 0;
+
+    if (n != 0) {
+        do {
+            result = mytolower(*l++) - mytolower(*r++);
+        } while ((result == 0) && (*l != '\0') && (--n > 0));
+    }
+    if (result < -1)
+        result = -1;
+    else if (result > 1)
+        result = 1;
+    return result;
+}
+
+
+// Scan the local file system for any .bin files and 
+// if they don't match the current one, remove them.
+//
+static bool RemoveOtherBinFiles(const char * name, int ver)
+{
+    char curbin[SW_MAX_FQFN];
+    DIR *d;
+    struct dirent *p;
+    bool noFailed = true;
+   
+    snprintf(curbin, SW_MAX_FQFN, "%s%03d.bin", name, ver);
+    INFO("Remove bin files excluding {%s}", curbin);
+    d = opendir("/local/");
+    // Get a directory handle
+    if ( d != NULL ) {
+        // Walk the directory
+        while ( (p = readdir(d)) != NULL ) {
+            INFO("  check {%s}", p->d_name);
+            // if the file is .bin and not curbin
+            if (0 == mystrnicmp(p->d_name + strlen(p->d_name) - 4, ".bin", 4)
+            && (0 != mystrnicmp(p->d_name, curbin, strlen(curbin)))) {
+                // remove the file
+                char toremove[SW_MAX_FQFN];
+                snprintf(toremove, SW_MAX_FQFN, "/local/%s", p->d_name);
+                INFO("    removing %s.", toremove);
+                if (remove(toremove)) {
+                    // set flag if it could not be removed
+                    noFailed = false;
+                }
+            }
+        }
+        closedir(d);
+    }
+    return noFailed;
+}
+
+SWUpdate_T SoftwareUpdate(const char *url, const char * name, Reboot_T action) {
     HTTPClient http;
     //http.setTimeout( 15000 ); 
-    char fqurl[150];    // fully qualified url
-    char verfn[32];     // local version file
-    char fwfn[32];
-    bool result = false;    // many things can go wrong, assume failure
-    char buf[50];
+    char fqurl[SW_MAX_URL];    // fully qualified url
+    char verfn[SW_MAX_FQFN];     // local version file
+    char fwfn[SW_MAX_FQFN];
+    uint16_t result = SWUP_OK;    // starting out quite optimistic, for all the things that can go wrong
+    char buf[50];           // long enough for 3 comma separated numbers...
         
     INFO("SoftwareUpdate(%s,%s)", url, name);
-    snprintf(verfn, 32, "/local/%s.ver", name);
+    snprintf(verfn, SW_MAX_FQFN, "/local/%s.ver", name);
 
     /* Read installed version string */
     int inst_ver = -1;
@@ -70,7 +150,7 @@
     
     /* Download latest version string */
     HTTPText server_ver("test message");
-    snprintf(fqurl, 150, "%s/%s.txt", url, name);
+    snprintf(fqurl, SW_MAX_URL, "%s/%s.txt", url, name);
     HTTPResult r = http.get(fqurl, buf, sizeof(buf));
     if (r == HTTP_OK) {
         int latest_ver = -1;
@@ -79,25 +159,21 @@
         int parseCount;
         parseCount = sscanf(buf, "%d,%d,%d", &latest_ver, &cksum, &fsize);
         if (parseCount == 3) {
-            INFO("  web version: %d", latest_ver);
-            INFO("     checksum: %d", cksum);
-            INFO("    file size: %d", fsize);
+            INFO("        web version: %d", latest_ver);
+            INFO("           checksum: %d", cksum);
+            INFO("          file size: %d", fsize);
             if (inst_ver != latest_ver) {
                 INFO("  Downloading firmware ver %d ...", latest_ver);
-                sprintf(fwfn, "/local/%s%d.BIN", name, latest_ver);
+                sprintf(fwfn, "/local/%s%03d.BIN", name, latest_ver);
                 snprintf(fqurl, 150, "%s/%s.bin", url, name);
         
                 HTTPFile latest(fwfn);
                 r = http.get(fqurl, &latest);
                 if (r == HTTP_OK) {
-                    // Check the integrity of the freshly downloaded file,
-                    // before swapping out the old version.
-                    // ... to appear here ...
                     if (PassesIntegrityCheck(fwfn, cksum, fsize)) {
-                        sprintf(fwfn, "/local/%s%d.BIN", name, inst_ver);
-                        INFO("  Firmware downloaded, removing old version (%s).", fwfn);
-                        if (remove(fwfn)) {
-                            ERR("  *** Failed to remove old version. ***");
+                        if (!RemoveOtherBinFiles(name, latest_ver)) {
+                            ERR("  *** Failed to remove old version(s). ***");
+                            result |= SWUP_OLD_STUCK;
                         }
                         INFO("Updating stored version number.");
                         fv = fopen(verfn, "w");
@@ -106,30 +182,35 @@
                             if (fr < 0) {
                                 ERR("Failed (%d) to update stored version number.", fr);
                                 fclose( fv );
+                                result |= SWUP_VER_STUCK;
                             } else {
                                 fclose( fv );
-                                if (reboot == AUTO_REBOOT) {
+                                if (action == AUTO_REBOOT) {
                                     WARN("Resetting...\n");
                                     wait_ms(200);
                                     mbed_reset();
                                 }
-                                result = true;
                             }
                         } else {
                             WARN("Failed to update local version info in %s.", verfn);
+                            result |= SWUP_VWRITE_FAILED;
                         }
                     } else {
                         WARN("New file {%s} did not pass integrity check.", fwfn);
+                        result |= SWUP_INTEGRITY_FAILED;
                     }
                 } else {
                     WARN("Failed to download lastest firmware.");
+                    result |= SWUP_BAD_URL;
                 }
             } else {
-                INFO("Online version is same as installed version.", parseCount);
+                INFO("Online version is same as installed version.");
+                result |= SWUP_SAME_VER;
             }
         }
     } else {
         WARN("Failed to download online firmware version number.");
+        result |= SWUP_HTTP_ERR;
     }
-    return result;
+    return (SWUpdate_T)result;
 }