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.
Some ESP8266/ESP8285 modules only work with DOUT SPI flash mode and a SPI flash frequency of 26 MHz. Therefore, these parameters have to be used by default. Otherwise some modules will no boot.
Startup information, including board configuration, is only printed when module esp_log_startup is used. This reduces the amount of information that is printed by default to the console during the startup. The user can enable module esp_log_startup to get the additional startup information.
To avoid that murdock times out before tests/pkg_spiffs and tests/pkg_littlefs time out, the configured test timeouts for these tests is reduced to 200 seconds which should be enough. An ESP32 needs an average of 60 seconds for these tests, while an ESP8266 needs in average 100 seconds.
The modified version esptool.py from RTOS SDK that is required for flashing an image, is now placed in `dist/tools/esptool.py` and used directly from there. The advantage is that `esptool.py` hasn't to be installed explicitly anymore. Having RIOT is enough. The documentation is adapted accordingly. The oly prerequisite is that python and the pyserial module are installed.
In vendor startup code, initialization function were called as parameters of assert statement. With DEVELHELP, they are not called since the assert macro does nothing.
To make the migration progress to the new RTOS SDK easier, the new toolchain was renamed to xtensa-esp8266-elf. This makes it possible to have the new and the old toolchain installed in parallel.
If the WiFi module is used, a number of high priority tasks is created. To void priority collisions with netdev drivers, the number of priorities SCHED_PRIO_LEVELS has to be increased to 32. But in other cases, the default number should be used, also to keep automatic tests working.
This reverts commit 422644bd3a.
The option is only supported after 2.6 which is currently not the
version given with 'esp' toolchain.
It was a bit too early to switch to the new version.
Version 2.7 also supports the old option with only a warning.
