Since former ESP32 toolchain versions used POSIX threads, module `pthread` was required. The built-in `cxa_ctor_guards` had to be replaced since they used the `pthread_once` function for singleton objects initialization where the parameter `once` was of incompatible type with that provided by RIOT's `pthread` module. The current ESP32 toolchain version no longer uses POSIX threads. The dependency on module `pthread` as well as according C++ hacks can be removed.
In #12955 optimization was switched to O2 because with the '-Os'
option, the ESP32 hangs sporadically in 'tests/bench*' if
interrupts where disabled too early by benchmark tests.
Since it hasn't been reproduced since and in #13196 O2 was causing
un-explained hardfaults, since the aforementioned issue could not
be reproduced we switch back to Os by removing O2, as Os will be
used by default.
GPIO32 and GPIO33 are used during boot to start an 32.768 kHz XTAL if it is connected to these GPIOs. If the 32.768 kHz XTAL is not connected, these pins can be used digital IO. However, the 32.678 kHz XTAL has to be disabled explicitly in this case. Furthermore, the handling of GPIOs greater than GPIO31 had to be fixed in I2C software implementation.
When entering a sleep mode, all wake-up sources should first be disabled before the wake-up sources required for the sleep mode are then stepwise enabled again. Otherwise, an wake-up configuration of one sleep mode may affect the wake-up within another sleep mode.
The WiFi interface should be stopped before reboot or sleep. But stopping the WiFi interface disconnects an existing connection. Usually, esp_wifi_netdev tries to reconnect on an disconnect event. However, trying reconnect with a stopped WiFi interface may lead to a crash. Therefore, the stop event has to be handled.
Now, where the vendor files for light/deep sleep mode are added, function `pm_off` does not need to implement this mode by itself. Instead the existing deep sleep with disabled wakeup sources is used for pm_off.
`rtc_init` is used after light sleep to update the system time from RTC timer. The fix corrects a small difference of about 230 ms which would sum up with each wakeup from light sleep.
