Fix silent failure of program when not aligned to flash blocks

Author: multiplemonomials

UpdaterApp.cpp

@@ -91,7 +91,12 @@ int main()
     }
 
     // Copy the update image from internal flash to secondary BlockDevice
-    secondary_bd->program(&_binary_SimpleApp_update_image_bin_start, 0, SimpleApp_update_image_bin_length);
+    ret = secondary_bd->program(&_binary_SimpleApp_update_image_bin_start, 0, SimpleApp_update_image_bin_length);
+    if (ret == 0) {
+        tr_info("Image copied.");
+    } else {
+        tr_error("Cannot copy image: %d", ret);
+    }
 
     ret = secondary_bd->deinit();
     if (ret == 0) {

secondary_bd.cpp

@@ -17,7 +17,11 @@ mbed::BlockDevice* get_secondary_bd(void) {
 
     // Use FlashIAP for the secondary BD.
     static FlashIAPBlockDevice flashBD(MBED_CONF_APP_SECONDARY_SLOT_FLASH_START_ADDR, MCUBOOT_SLOT_SIZE);
-    return &flashBD;
+
+    // Our UpdaterApp needs to be able to program the flash with single-byte granularity
+    static mbed::BufferedBlockDevice bufferedBD(&flashBD);
+
+    return &bufferedBD;
 }
 
 #else