Previously the concepts of initLength and lenth were clearly separated.
However, this was at the cost of registering all characteristics in the
SoftDevice as having variable length. Clearly, this is not the desired
behaviour. Therefore, an additional field '_hasVariableLen' is added to the
GattAttribute to address the problem. Also, the GattAttribute and
GattCharacteristic constructors have been modified to take a boolean that
sets '_hasVariableLen'.
**NOTE:** Changes to this module will cause projects to fail the build stage
if changes to the BLE_API are not published first.
In previous versions of BLE_API the GattCharacteristic initLen parameter is
named minLen as well. When the characteristic is committed to the SoftDevice
the value of initial length is also used as the minimum length of the
characteristic value. Furthermore, the test (max_length == min_length) is used
to determine whether the characteristic value has variable length. This is
slightly confusing and also causes problems if the user wishes to use a
characteristic with variable length but the initial lenght is equal to max
length.
To solve this problem the characteristic is now always committed to the
SoftDevice as variable. Furthermore, the API only maintains the current lenght
and the max length i.e. the field initialLen in the GattAttribute is removed.
In nRF5xGattServer all calls to getInitialLength() are removed and replaced
with getLength().
*NOTES:*
* This change requires updates to ble.
* Ideally we would like the characteristics to be declared as 'variable' only
when necessary, but this requires changing the signature of the
GattCharacteristic and GattAttribute constructors. Therefore, it will be part
of a separate pull request.
=============
* Fix a bug in the assembly sequence that starts the Nordic bootloader. With
GCC, a MOV instruction was getting converted into an ADDS, which came with
an unwanted side-effect of updating the XPSR. We relocated the offending MOV
instruction such that it would not affect a conditional branch statement.
This would show only with GCC, and when jumping to the bootloader while in
handler mode.
* Fix hardfaults generated from the handling of Radio Notification events.
Radio notification events are interrupts generated at very high priority.
They have the potential to pre-empt other interrupt handling, causing race
conditions when interrupted handlers were involved in calling into BLE_API.
Radio-notification events should defer their callback handling to low-
priority handlers through the use of Tickers or Timeouts.
* Introduce watchdog header file from Nordic SDK 8.1.
* Update license headers to reflect the latest licenses from Nordic.
The ble-nrf51822 implementation of the BLE API executes callbacks for radio
notification events at very high priority. This functionality is replaced by
executing the radio notification callback at a lower priority. When using
mbed OS the callback is posted through minar. In mbed classic the callback is
executed directly, but from a lower priority. Note that minar or callback
execution in mbed classic could not be posted/generated directly from the
radio notification handler because this causes race conditions that may lead
to a hard-fault. Alternatively, a Timeout was used to post the callback in
another context with lower priority.
Rohit Grover