Module `newlib` is now used by default. Therefore, the separation of initialization of ctors and the newlibc is not needed any longer. Instead of calling `do_global_ctors` and `_init` separately, `__libc_init_array` is called. Explicit function `do_global_ctors` is removed.
Initializing the stdio file descriptors in global reent structure with newlib fake stdio file descriptors led to the problem that newlib stdio functions printf and puts were not working since they can't operate on these fake stdio file descriptors. Therefore, this initialization was removed. Now, the real stdio file descriptors as created automatically by newlib are used. Specific functions `printf`, `puts`, `getchar`and `putchar` are not required any longer and are removed now.
Modules newlib and newlib_syscalls_default are now used by default. Conditional compilations for MODULE_NEWLIB_SYSCALLS_DEFAULT as well as alternative code are removed completely.
printf and puts used ets_printf before. Unfortunately, ets_printf adds an additional \r for each \n which is not consistent with other RIOT platforms. As a result some automatic tests failed. Therefore, both functions write now character-wise directly to the UART interface.
Using a mutex for critical section handling with portENTER_CRITICAL and portEXIT_CRITICAL does not work for RIOT, as this function can also be called in the interrupt context. Therefore, the given mutex is not used. Instead, the basic default FreeRTOS mechanism for critical sections is used by simply disabling interrupts. Since context switches for the ESP32 are also based on interrupts, there is no possibility that another thread will enter the critical section once the interrupts are disabled.
The option value length of Ethernet addresses can be more than 6 byte in lwIP. Therefore, the max_len parameter is check to be greater than or equal to ETHERNET_ADDR_LEN.
Module esp_idf_heap is enabled in cpu/esp32/Makefile.dep depending on other modules. Since cpu/esp32/Makefile.dep is read after cpu/esp32/Makefile.include, the conditional definition of the linker options for the wrapper functions had to be moved from cpu/esp32/Makefile.include to cpu/esp32/Makefile.dep.
If module esp_idf_heap is used, the memory management functions _malloc_r, _realloc_r, _calloc_r and _free_r have to be overridden by wrapper functions to use the heap_* functions of module _esp_idf_heap. However, this can lead to multiple symbol errors for these functions for some applications. To solve this symbol conflict, _malloc_r, _realloc_r, _calloc_r and _free_r functions are renamed to __wrap_* and the linker options are extended by -Wl,-wrap option when module esp_idf_heap is used.
When standard C libraries are added to BASELIBS to group them together with all other modules, there are multiple definitions for the putchar function. The one that is defined writing to the UART as standard output and the one that is provided by the standard C libraries. To solve this symbol conflict, putchar and getchar functions that use the UART as standard output/input are renamed to __wrap_putchar and __wrap_getchar and the linker options are extended by -Wl,-wrap option.
When linking an application, symbol pthread_setcancelstate is not known in standard C libraries, even if the pthread module is linked. This is because the pthread module is grouped with all other modules, but not with the default C libraries when they are added to LINK_FLAGS. Therefore, standard C libraries have to be added also to BASELIBS to group them with all other modules.
Fixes the problem that the compilation of an applications can throw unknown symbol errors for functions that aren't use at all. Thus, it is possible to remove the warning for unknown symbols and the compilation can abort if there are real unknown symbols.
Rational: the periph_common module is required by (most) other periph drivers
and also during startup of the CPU/MCU to run periph_init. The latter is only
required if other periph drivers are used, hence periph_common should be a
depency of periph_* modules and *not* of the CPU/MCU. This PR fixes that
by making periph_common a depency of periph_* and removing the explicit
include in the CPU/MCU implementation.
PREFLASHER/PREFFLAGS/FLASHDEPS are evaluated by the main Makefile.include.
Their value does not need to be exported.
Testing
-------
`git diff --word-diff` only reports `export` being removed.
`git show --stat` reports `16 insertions(+), 16 deletions(-)`
Which is the same amount as lines that where matching
`export[[:blank::]]\+VARIABLE` plus the newline that is said to have
changed.
FLASHER and FFLAGS are evaluated by the main Makefile.include or by file
included by it. Their value does not need to be exported.
This will also prevent evaluating 'PORT' for FFLAGS when not needed.
Testing
-------
`git diff --word-diff` only reports `export` being removed.
`git show --stat` reports `84 insertions(+), 84 deletions(-)`
Which is the same amount as lines that where matching
`export[[:blank::]]\+VARIABLE`.
UART devices are now configured using static array in header files instead of static variables in implementation to be able to define UART_NUMOF using the size of the array instead of a variable.
SPI devices are now configured using static array in header files instead of static variables in implementation to be able to define SPI_NUMOF using the size of the array instead of a variable.
I2C devices are now configured using static array in header files instead of static variables in implementation to be able to define I2C_NUMOF using the size of the array instead of a variable.
DAC pins are now configured using static arrays in header files instead of static variables in implementation to be able to define DAC_NUMOF using the size of these arrays instead of a variable.
ADC pins are now configured using static arrays in header files instead of static variables in implementation to be able to define ADC_NUMOF using the size of these arrays instead of a variable.
