QISEND command can respond either SEND OK, SEND FAIL or ERROR.
If response is not SEND OK, sent bytes should not be checked but
error should be reported.
Possible responses for send command are SEND OK<cr><ln>, SEND FAIL<cr><ln> or ERROR<cr><ln>
so normal OK<cr><ln> response check does not work properly.
Multihoming documentation about interface name:
"Two character name string is concatenated with 8 bit value containing index which is incremented on each netif addition"
Cellular uses context id as index and to follow LWIP (LWIP::Interface::get_interface_name), index does not include leading zeros.
A new API `CellularDevice::clear()` to clean-up the modem to a default initial state.
Function is virtual so it can be overridden. The default implementation clears all PDP contexts,
but the the first one if that has APN defined as `nsapi.default-cellular-apn`.
CellularStateMachine calls `clear()` to clean-up the modem on initial `connect()`,
if the flag `cellular.clear-on-connect: true` is defined.
In some multithread cases there is possibility that process_oob function
was called after ATHandler was deleted. Fix is to wait if oob processing
is ongoing.
New ATHandler functions taken into use for rest of the targets (BG96 was updated initially) to reduce code size. This means basically that new functions using variadic list approach are taken into use and with those one can usually write AT commands in single line instead of multiple lines.
Only internal changes and API's are not modified.
When AT+CGML is used to retrieve list of SMS stored in modem inbox,
every message has an associated index. ETSI TS 127 005 v7.0.0 does not
specify what is the allowed range of such indices - all it says is
"integer type; value in the range of location numbers supported by the
associated memory".
Usually, AT modems use positive indexes (starting at 1). Quectel BG96
modem takes a different approach, indexing messages starting at 0.
Current implementation of `AT_CellularSMS::list_messages()` considers
index 0 invalid and ignores such message, effectively making it
impossible to access using mbed-os API.
This commit changes the behavior so that value of 0 is handled as any
other positive message index.