+--------+    +-----------------+    +-----------------------------+
|        |    | Firmware Server |    |         IoT Device          |
| Author |    | Status Tracker  |    | +------------+ +----------+ |
+--------+    | Server          |    | |  Firmware  | |Bootloader| |
  |           +-----------------+    | |  Consumer  | |          | |
  |                   |              | +------------+ +----------+ |
  |                   |              |      |                |     |
  |                   |              |  +-----------------------+  |
  | Create Firmware   |              |  | Status Tracker Client |  |
  |--------------+    |              |  +-----------------------+  |
  |              |    |               `''''''''''''''''''''''''''''
  |<-------------+    |                     |        |       |
  |                   |                     |        |       |
  | Upload Firmware   |                     |        |       |
  |------------------>|                     |        |       |
  |                   |                     |        |       |
  | Create Manifest   |                     |        |       |
  |---------------+   |                     |        |       |
  |               |   |                     |        |       |
  |<--------------+   |                     |        |       |
  |                   |                     |        |       |
  | Sign Manifest     |                     |        |       |
  |-------------+     |                     |        |       |
  |             |     |                     |        |       |
  |<------------+     |                     |        |       |
  |                   |                     |        |       |
  | Upload Manifest   |                     |        |       |
  |------------------>|  Notification of    |        |       |
  |                   |  new firmware image |        |       |
  |                   |----------------------------->|       |
  |                   |                     |        |       |
  |                   |                     |Initiate|       |
  |                   |                     | Update |       |
  |                   |                     |<-------|       |
  |                   |                     |        |       |
  |                   |   Query Manifest    |        |       |
  |                   |<--------------------|        .       |
  |                   |                     |        .       |
  |                   |   Send Manifest     |        .       |
  |                   |-------------------->|        .       |
  |                   |                     | Validate       |
  |                   |                     | Manifest       |
  |                   |                     |--------+       |
  |                   |                     |        |       |
  |                   |                     |<-------+       |
  |                   |                     |        .       |
  |                   |  Request Firmware   |        .       |
  |                   |<--------------------|        .       |
  |                   |                     |        .       |
  |                   | Send Firmware       |        .       |
  |                   |-------------------->|        .       |
  |                   |                     | Verify .       |
  |                   |                     | Firmware       |
  |                   |                     |--------+       |
  |                   |                     |        |       |
  |                   |                     |<-------+       |
  |                   |                     |        .       |
  |                   |                     | Store  .       |
  |                   |                     | Firmware       |
  |                   |                     |--------+       |
  |                   |                     |        |       |
  |                   |                     |<-------+       |
  |                   |                     |        .       |
  |                   |                     |        .       |
  |                   |                     |        .       |
  |                   |                     |        |       |
  |                   |                     | Update |       |
  |                   |                     |Complete|       |
  |                   |                     |------->|       |
  |                   |                              |       |
  |                   |  Firmware Update Completed   |       |
  |                   |<-----------------------------|       |
  |                   |                              |       |
  |                   |  Reboot                      |       |
  |                   |----------------------------->|       |
  |                   |                     |        |       |
  |                   |                     |        |       |
  |                   |                     |        |Reboot |
  |                   |                     |        |------>|
  |                   |                     |        |       |
  |                   |                     |        .       |
  |                   |                 +---+----------------+--+
  |                   |                S|   |                |  |
  |                   |                E|   | Verify         |  |
  |                   |                C|   | Firmware       |  |
  |                   |                U|   | +--------------|  |
  |                   |                R|   | |              |  |
  |                   |                E|   | +------------->|  |
  |                   |                 |   |                |  |
  |                   |                B|   | Activate new   |  |
  |                   |                O|   | Firmware       |  |
  |                   |                O|   | +--------------|  |
  |                   |                T|   | |              |  |
  |                   |                 |   | +------------->|  |
  |                   |                P|   |                |  |
  |                   |                R|   | Boot new       |  |
  |                   |                O|   | Firmware       |  |
  |                   |                C|   | +--------------|  |
  |                   |                E|   | |              |  |
  |                   |                S|   | +------------->|  |
  |                   |                S|   |                |  |
  |                   |                 +---+----------------+--+
  |                   |                     |        .       |
  |                   |                     |        |       |
  |                   |                     .        |       |
  |                   |  Device running new firmware |       |
  |                   |<-----------------------------|       |
  |                   |                     .        |       |
  |                   |                              |       |