This will be used by https://micropython.org/download/ to generate the
full listing of boards and firmware files.
Optionally supports a board.md for additional customisation of the
download page, as well as deploy.md for flashing instructions.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Add a new board type for ESP32-C3 revision 3 and up that implement the USB
serial/JTAG port on pin 18 and 19. This variant uses the USB serial for
programming and console, leaving the UART free.
- Pins 18 and 19 are correctly reserved for this variant. Also pins 14-17
are reserved for flash for any ESP32-C3 so they can't be reconfigured
anymore to crash the system.
- Added usb_serial_jtag.c and .h to implement this interface.
- Interface was tested to work correctly together with webrepl.
- Interface was tested to work correctly when sending and receiving
large files with ampy.
- Disconnecting terminal or USB will not hang the system when it's
trying to print.
