This fixes a race in `LED<NUM>_TOGGLE`, which is a read-copy-write
operation. Any access to a GPIO pin on the same GPIO port that
happens concurrently could result in data corruption. Using the
GPIO LL API, which is thread-safe, fixes the issue.
Note: The used GPIO LL functions will work even in when the GPIO LL
module is not used.
The `SWJ_CFG` field of the `AFIO_MAPR` register is write only and values
read are undefined (random). Hence, using `AFIO->MAPR |= mask;` to
enable flags can corrupt the state of the `SWJ_CFG` (configure it to
an unintended value).
Two helper functions have been introduced:
- `afio_mapr_read()` reads the value, but sanitizes the `SWJ_CFG` field
to zero
- `afio_mapr_write()` writes the given value, but applies the `SWJ_CFG`
configured by the board before writing.
Finally, the `nucleo-f103rb` and `bluepill*`/`blackpill*` boards have
been updated to no longer specify `STM32F1_DISABLE_JTAG`, as this
is handled by the `SWJ_CFG` setting (which defaults to disabling JTAG).
Using `UART_DEV(0)` (UASRT1) for stdio allows to use the same TTL
adapter that is used for programming via `stm32flash` to be used for
serial, without re-wiring after flashing.
Let boards only define the port and pin number of each LEDs. The common
definitions in `stm32_leds.h` will provide `LED<x>_ON`, `LED<x>_OFF`,
`LED<x>_TOGGLE`, `LED<x>_PIN`, `LED<x>_MASK` and `LED<x>_PORT`.
In addition to code de-duplication, this also makes it easier to use
LEDs in GPIO LL, which can be beneficial for super low overhead
debugging output - e.g. when a bug is timing sensitive and `DEBUG()`
would spent to much time for stdio to reproduce a bug.
The Nucleo-F103RB comes with an internal SWD programmer/debugger. Thus, the JTAG
pins are not going to be used for debugging / programming anyway. The pins are
exposed on the headers, so allowing them to be used as GPIOs make a lot of
sense.
The Bluepill / Blackpill boards only expose the SWD pins on the debug header,
but the JTAG pins (not also used by SWD) are exposed on the GPIO pin headers.
Hence, exposing them as regular GPIOs seems to be a reasonable choice.
- Created new `bluepill-128kib` as 128KiB version of the `bluepill`
- Created new `blackpill-128kib` as 128KiB version of the `blackpill`
- Updated `openocd.cfg` to allow flashing 128KiB of ROM
