OTA support

If a device includes rpc-service-ota library, then it can be updated remotely. The three RPC functions that perform the OTA are OTA.Begin, OTA.Write and OTA.End.

mDash provides a convenience RESTful handler for the OTA, where you can just POST the new firmware .zip file, and mDash will call OTA.Begin followed by a sequence of OTA.Write calls, finished by OTA.End.

The OTA can be performed either via the Web UI, or programmatically using the REST API:

curl -H 'Authorization: Bearer API_KEY' \
  -v -F file=@fw.zip
  http://dash.mongoose-os.com/api/v2/devices/DEVICE_ID/ota
true

Once the firmware is updated, the device reboots in the "dirty", uncommitted state. An OTA.Commit call must be done to bless the new firmware, otherwise it will rollback, thinking that the health check did not pass. You can call OTA.Commit as any other RPC method. mDash provides a handy commit button for the convenience, when it sees an uncommitted device.