Fix of #11354: Function '_write_r' of ESP32's newlibc does not write the output of function 'write(STDIO_FILENO, ...)' to the UART interface. To fix this problem, module 'newlib_syscalls_default' is now used by default. Function '_write_r' of module 'newlib_syscalls_default' uses 'stdio_write' which in turn uses 'uart_write' if module 'stdio_uart' is used which is now the default case for ESP32.
The GPIO for RX has to be initialized as input before the GPIO for TX can be initialized as output. Otherwise it could lead to creash if RX GPIO was used as output before.
Function uart_set_baudrate which is only used internally was made static and renamed to _uart_set_baudrate to indicate that it is an internal function. Furthermore, an additional waiting for flushed TX FIFO added. The reconfiguration is now handled as critical section.
An additional _ for static symbols has been added by mistake and should be removed. This will make future merging with the reimplementation of ESP8266 easier.
The build system contains several instances of
INCLUDES += -I$(RIOTBASE)/sys/posix/include
This is bypassing the module management system, by directly accesing
headers without depending on a module. The module is the posix module.
That line is also added when one of the posix_* modules is requested.
According to the docs, the posix module provides headers only, but in
reality there is also inet.c.
This patch:
- Moves `inet.c` into `posix_inet`, leaving `posix` as a headers-only
module.
- Rename `posix` as `posix_headers` to make it clear the module only
includes headers.
- Makes `posix_*` modules depend on `posix_headers`, thus removing the
explicit `INCLUDES+=...` in `sys/Makefile.include`.
- Ocurrences of `INCLUDES+=...` are replaced by an explicit dependency
on `posix_headers`.
The default macros GPIO_PIN and GPIO_UNDEF do not have to be overridden. The GPIO_PIN macro definition was even wrong for 40 GPIOs without splitting into ports, even if that did not lead to erroneous behavior.
Fixes sporadic blocking of the wifi thread in esp_wifi_recv_cb function under heavy network load conditions when frames are coming in faster than they can be processed. Since esp_wifi_recv_cb function is not executed in interrupt context, the msg_send function used for ISR event can block when the message queue is full. With this change esp_wifi can be flooded with icmpv6 packets of maximum size without any problems over hours.
RX callback function should be register when WiFi has been connected to AP successfully and should be unregistered when WiFi disconnects from AP. Therefore, esp_wifi_internal_reg_rxcb is called now in event handler on event SYSTEM_EVENT_STA_CONNECTED. It is reset now on event SYSTEM_EVENT_STA_DISCONNECTED.
Before function wifi_connect is executed, starting the WiFi driver should have been finished. This is indicated by the WiFi driver by sending event SYSTEM_EVENT_STA_START. Function wifi_connect is moved therefore to the event handler for SYSTEM_EVENT_STA_START.
The size of received and transmitted frames was stored in an uint8_t, which did not allow to process frames larger than 255 octets. However, WiFi has an MTU of 1500 octets.
Adds a memset function `system_secure_memset` which cannot be optimized out by the compiler. It uses the libsodium approach of weak symbols. Function system_secure_memset calls the standard memset. Calling an empty function declared with weak attribute after the memset call, prevents the compiler to optimize it out. The overhead is only one function call.
Although ESP32 has four SPI controllers, only two of them can be effectively used (HSP and VSPI). The third one (FSPI) is used for external memory such as flash and PSRAM and can not be used for peripherals. FSPI is therefore removed from the API. In addition, the SPI0_DEV and SPI1_DEV configuration parameters are renamed SPI0_CTRL and SPI1_CTRL to better describe what they define and to avoid confusion with SPI_DEV (0) and SPI_DEV (1).
Although ESP32 has four SPI controllers, only two of them can be effectively used (HSP and VSPI). The third one (FSPI) is used for external memory such as flash and PSRAM and can not be used for peripherals. FSPI is therefore removed from the API. In addition, the SPI0_DEV and SPI1_DEV configuration parameters are renamed SPI0_CTRL and SPI1_CTRL to better describe what they define and to avoid confusion with SPI_DEV (0) and SPI_DEV (1).
cpu/esp32/include/periph_cpu.h overrides the default definition of adc_res_t from periph/adc with a definition which contains only four resolution, two new resolutions and two resolutions defined by the default definition of adc_res_t. This gives compilation errors if an application uses other resolutions. According to the documentation, adc_sample should return -1 if the resolution is not supported. All other CPUs override adc_res_t either to add new resolutions or to mark resolutions as unsupported. But they all allow to use them at the interface. Therefore, esp32 overrides now the definition of adc_res_t with all resolutions that are defined by the default definition of adc_res_t and new platform specific resolutions. It returns -1 if a resolution is used in adc_sample that is not supported.
