tree 69a6c11d27f1e907f39d5a0844f2ee45c6bef44e
parent 305588686ab387c6481dc1e8c12d3791568e4009
author Bill Richardson <wfrichar@google.com> 1519326591 -0800
committer Andrew Scull <ascull@google.com> 1525366478 +0100

Support message CRCs in the transport protocol.

This adds CRC-16 checksums for the call_application() function. The
command from the master includes and additional packet containing the
CRC which the slave can verify. The status from the slave after an app
has processed the command included the CRC of the reply data and the
status message itself.

The protocol is backward compatible by detecting the legacy protocol
from the status response and ignoring any CRCs.

In the event of a CRC failure when reading the status or response data,
the read operation is retried 3 times. In the event of a CRC failure of
the request, the transaction is restarted a maximum of 3 times.

Bug: 66104849
Change-Id: Id8c8e1ce0425af66a3a41e59cf7bb3843a4bf740