RIOT-OS uses part of Espressif ESP8266 RTOS SDK to build support for
this CPU. The SDK includes some vendor-provided closed source
pre-compiled libraries that we need to modify to adapt to RIOT-OS
usage. This library modifications was done once and uploaded to a fork
of the vendor repository and was provided as an environment variable.
This patch changes two things:
1. It installs the SDK as a RIOT PKG from the new pkg/esp8266_sdk
directory instead of requiring the user to download it separately.
2. It performs the library modifications (symbol renames) on the pkg
Makefile removing the need to use a fork with the modifications applied
and simplifying the SDK update and future modifications.
This change sets the SDK package version (git SHA) to the same one that
our fork was using as a parent in the vendor repository, meaning that
the output libraries are exactly the same as before.
Tested with
```
ESP8266_RTOS_SDK_DIR=/dev/null USEMODULE=esp_log_startup make -C tests/shell BOARD=esp8266-esp-12x flash
```
and verified that the program works. The boot message now includes:
```
ESP8266-RTOS-SDK Version v3.1-51-g913a06a9
```
confirming the SDK version used.
`/dev/null` in the test is just to make sure that no evaluation of
`ESP8266_RTOS_SDK_DIR` in make is affected by the environment variable
value which would be set to the SDK for people who followed the set up
instructions before this change.
Tested the checkout size:
```bash
$ du -hs build/pkg/esp8266_sdk/
124M build/pkg/esp8266_sdk/
```
If esp_idf_heap is not used, implement calloc through a custom wrapper
function on top of malloc to add overflow detection, which is not
present in the newlib forks with xtensa support yet.
This is an implementation of the ESP32 SoftAP mode using the
`esp_wifi_ap` pseudomodule.
Signed-off-by: Jean Pierre Dudey <jeandudey@hotmail.com>
Co-authored-by: Gunar Schorcht <gunar@schorcht.net>
Flashing an ESP board first requires the creation of a flash image from the ELF file. This is realized in the `preflash` target. However, the `preflash` target only depends on the variable `BUILD_BEFORE_FLASH` but on the ELF file. Therefore, the variable `BUILD_BEFORE_FLASH` must be set to the ELF file to ensure that when using multiple make processes, the compilation of the ELF file is completed before the flash image is created.
