When FreeRTOS semaphores, as required by ESP-IDF, are used together with `gnrc_netif`, RIOT may crash if `STATUS_RECEIVE_BLOCKED` is used as a blocking mechanism in the FreeRTOS adaptation layer. The reason for this is that `gnrc_netif` uses thread flags since PR #16748. If the `gnrc_netif` thread is blocked because of a FreeRTOS semaphore, and is thus in `STATUS_RECEIVE_BLOCKED` state, the `_msg_send` function will cause a crash because it then assumes that `target->wait_data` contains a pointer to a message of type `msg_t`, but by using thread flags it contains the flag mask. This situation can happen if the ESP hardware is used while another thread is sending something timer controlled to the `gnrc_netif` thread.
To solve this problem `STATUS_MUTEX_LOCKED` is used instead of `STATUS_RECEIVE_BLOCKED` and `STATUS_SEND_BLOCKED`
To reduce the required RAM in default configuration, the BLE interface is used as netdev_default instead of ESP-NOW. Further network interfaces can be enabled with the modules `esp_now`, `esp_wifi` or `esp_eth`.
When using Bluetooth LE, the former UART interrupt number 5 is occupied by the ESP32 Bluetooth Controller. Therefore, another interrupt number has to be used for UART.
The package uses the nRFx SDK package `nrfx`. In addition, the `mynewt-nimble` repository contains some files (`porting/nimble/src/hal_timer.c` and `porting/npl/riot/src/nrf5x_isr.c`) that are compilable only for nRF MCUs. To allow the compilation for other platforms, the use of the `nrfx` package and the compilation of these files are now dependent on the use of any nRF5x MCU.
This define does not belong to the defines in `sdkconfig_*.h` that are used for the ESP-IDF SDK. It is therefore moved to the corresponding `periph_cpu_*.h` file.
A if `netdev_driver_t::confirm_send()` is provided, it provides the
new netdev API. However, detecting the API at runtime and handling
both API styles comes at a cost. This can be optimized in case only
new or only old style netdevs are in use.
To do so, this adds the pseudo modules `netdev_legacy_api` and
`netdev_new_api`. As right now no netdev actually implements the new
API, all netdevs pull in `netdev_legacy_api`. If `netdev_legacy_api` is
in used but `netdev_new_api` is not, we can safely assume at compile
time that only legacy netdevs are in use. Similar, if only
`netdev_new_api` is used, only support for the new API is needed. Only
when both are in use, run time checks are needed.
This provides two helper function to check for a netif if the
corresponding netdev implements the old or the new API. (With one
being the inverse of the other.) They are suitable for constant folding
when only new or only legacy devices are in use. Consequently, dead
branches should be eliminated by the optimizer.
