Add `TARGET_ARCH_<ARCH>` for each architecture (e.g. `TARGET_ARCH_CORTEX` for
Cortex M) to allow users to overwrite the target triple for a specific arch
from ~/.profile or ~/.bashrc (or the like) without overwriting it for all others
as well.
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.
The same tool 'gen_esp32part.py' is used for the generation of partition tables on ESP8266 as well as n ESP32. The tool is therefore added to 'dist/tools/esptool'
It is possible to use different timers as RTC timer for the periph_rtc module. Either the 48-bit RTC hardware timer is used directly or the PLL driven 64-bit system timer emulates a RTC timer. The latter one is much more accurate. Pseudomodule esp_rtc_timer controlls which timer is used. Only if esp_rtc_timer is enabled explicitly, the 48-bit RTC hardware timer is used. Otherwise the 64-bit sytstem timer is used to emulate the RTC timer.
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.
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.
To reduce the information that are printed at the console during the startup, special bootloaders are required that suppress the outputs which are only informational. The according bootloader has to be selected during the make process.
If the user or the board definition doesn't enable `esp_wifi` or `esp_eth`, `esp_now` is defined as default netdev.
fixup! cpu/esp32: defines esp_now as default netdev
A number of tests insist that the number of thread priority levels is 16. However, when using the WiFi interface, a number of high priority threads are required to handle the WiFi hardware. In this case, the number of thread priority levels must be 32. Solves the problem of tests `tests/shell`.
ESP32 log output was always tagged with additional information by default. The tag consists the type of the log message, the system time in ms, and the module or function in which the log message is generated. By introducing module `esp_log_tagged`, these additional information are disabled by default and can be enabled by using module `esp_log_tagged`.
Log module of ESP32 supports colored log outputs when module `esp_log_color` is enabled. The generation of colored log outputs is realized by a extending the bunch of macros with an additional letter indicating the type of log message,
For the implementation of the colored log output, two versions of the bootloader are introduced, one version with colored log output and one version without colors.
