The toolchain provides POSIX type definitions for pthread which conflicts with that in RIOT. With the CFLAGS/CXXFLAGS skip the inclusion of the types shipped by the toolchain.
The vendor binary libraries of ESP-IDF are provided as a separate GIT repository. These libraries are defined as separate package for two reasons: 1. RIOT packages don't support to clone GIT repositories recursively; 2. ESP-IDF pulls a lot of other GIT repositories that are not needed when it is cloned recursively.
Checksumming flash is not supported on xtensa platform:
Warn : not implemented yet
make: *** [.../RIOT/examples/saul/../../Makefile.include:796: flash] Error 1
https://github.com/espressif/openocd-esp32 is needed.
Example config (when compiled from source):
export OPENOCD="~/esp/openocd-esp32/src/openocd -s ~/esp/openocd-esp32/tcl"
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.
