On MCUs other than F4 the ORE (overrun error) flag needs to be cleared
independently of clearing RXNE, even though both are wired to trigger the
same RXNE IRQ. In the case that an overrun occurred it's necessary to
explicitly clear the ORE flag or else the RXNE interrupt will keep firing.
Otherwise IRQs may not be enabled for the user UART.irq() handler. In
particular this fixes the user IRQ_RXIDLE interrupt so that it triggers
even when there is no RX buffer.
The new option MICROPY_HW_SDCARD_MOUNT_AT_BOOT can now be defined to 0 in
mpconfigboard.h to allow SD hardware to be enabled but not auto-mounted at
boot. This feature is enabled by default to retain previous behaviour.
Previously, if an SD card is enabled in hardware it is also used to boot
from. While this can be disabled with a SKIPSD file on internal flash,
this wont be available at first boot or if the internal flash gets
corrupted.
GNU readline support for the unix port was removed in
acaa30b6046d449f5f58a8f02c83459702759df7 and in
5e83a75c78dc8c370b25e7ee669295854ea45130, so it's also no longer supported
in the windows port.
Due to new webpages at nordicsemi.com, the download links
for Bluetooth LE stacks were broken.
This patch updates the links to new locations for the current
targets.
This UART_HandleTypeDef is quite large (around 70 bytes in RAM needed for
each UART object) and is not needed: instead the state of the peripheral
held in its registers provides all the required information.
The pin alternate function information is derived from ST's datasheet
https://www.st.com/resource/en/datasheet/stm32l432kc.pdf
In the datasheet, the line 2 of AF4 includes I2C2 but actually the chip
does not have I2C2 so it is removed.
As per the machine.UART documentation, this is used to set the length of
the RX buffer. The legacy read_buf_len argument is retained for backwards
compatibility, with rxbuf overriding it if provided.
Also change the order of printing of flow so it is after stop (so bits,
parity, stop are one after the other), and reduce code size by using
mp_print_str instead of mp_printf where possible.
See issue #1981.
This is necessary for two reasons: 1) FreeRTOS still needs the TCB data
structure even after vPortCleanUpTCB has been called, so this latter hook
function cannot free the TCB, and there is no where else to safely delete
it (this behaviour has changed recently in the ESP IDF); 2) when using
external SPI RAM the uPy heap is in this external memory but the task stack
must be allocated from internal SRAM.
Fixes issue #3904.
