To control the log level and the format of the log output of SDK libraries, a bunch of library-specific printf functions are realized which map the log output from SDK libraries to RIOT's log macros.
Usually, the access to the IROM (flash) memory requires 32-bit word aligned reads. Attempts to access data in the IROM (flash) memory less than 32 bits in size triggers a LoadStoreError exception. With the exception handler from esp-open-rtos it becomes possible to access data in IROM (flash) with a size of less than 32 bits and thus to place .rodata sections in the IROM (flash).
Timer restart was moved from esp_now_scan_peers_done to esp_now_scan_peers_start to avoid that the scan for peers isn't triggered anymore if the esp_now_scan_peers_done callback isn't called because of errors.
Since it is not possible to reenter the function `esp_now_recv_cb`, and the functions netif::_ recv and esp_now_netdev::_ recv are called directly in the same thread context we can read directly from the `buf` and don't need a receive buffer anymmore.
Since it is not possible to reenter the function `esp_now_recv_cb`, and the functions netif::_ recv and esp_now_netdev::_ recv are called directly in the same thread context we only need a buffer which contains one frame and its source mac address.
Since it is not possible to reenter the function `esp_now_recv_cb`, and the functions netif::_ recv and esp_now_netdev::_ recv are called directly in the same thread context, neither a mutual exclusion has to be realized nor have the interrupts to be deactivated.
Since the esp_now_recv_cb function is not called directly as an ISR through interrupts, it is not executed in the interrupt context. _recv can therefore be called directly. The treatment of the recv_event is no longer necessary.
Although it should not be possible to reenter the function esp_now_recv_cb, this is avoided by an additional boolean variable. It can not be realized by mutex because it would reenter from same thread context. If macro NDEBUG is not defined, an assertion is used.
Avoids parsing IPv6 packets to determine destination address.
Allows using 6Lo over ESP-NOW, which is required due to the low MTU of
ESP-NOW.
Co-authored-by: Gunar Schorcht <gunar@schorcht.net>
