Module for upgrading firmware on target devices.

Required options:

• manufacturer_id - The unique id indentifying the manufacturer of the target device
• firmware_id - The id of the current firmware

Other options:

• device_id - Node id of the device to be updated. Defaults to 1 (controller)
• firmware_target - The firwmare target id. Defaults to 0 (the ZWave chip)
• max_fragment_size - The maximum number of bytes that will be transmitted at a time. Defaults to 2048.
• hardware_version - The current hardware version of the device to be updated. Defaults to 0.
• activation_may_be_delayed? - Whether it is permitted for the device may delay the actual firmware update. Defaults to false.
• handler - The process that will receive callbacks. Defaults to the caller.any()

The firmware update process is as follows:

1. Grizzly sends a firmware_md_get command to the target device to get the manufacturer_id, hardware_id, max_fragment size, among other info needed to specify a firmware update request. The info is returned via a firmware_md_report command.

2. Grizzly uses this info to send a firmware_update_md_request command to the target device, telling it to initiate the image uploading process. The checksum of the entire firmware image is added to the request. The target device says yeah or nay via a firmware_update_md_request_report command.

3. If the target device agrees to have its firmware updated, it next sends a first firmware_update_md_get command to Grizzly asking for a number_of_reports (a bunch of firmware image fragment uploads) starting at fragment report_number.

4. Grizzly responds by sending the requested series of firmware_update_md_report commands to the target device, each one containing a firmware image fragment, with a checksum for the command.

5. Once a series of uploads is completed, the target device either asks for more fragments via another firmware_update_md_get command, or it sends a firmware_update_md_status_report command either to cancel the yet incomplete upload (bad command checksums!), or to announce that the update has completed either successfully (with some info about what happens next) or in failure (invalid overall image checksum!).

6. As part of a successful firmware_update_md_status_report command, the target device tells Grizzly whether the new firmware needs to be activated. If it does, Grizzly would then be expected to send a firmware_update_activation_set command which success is reported by the target device via a firmware_update_activation_report command.