At startup, buffer initial stdout / MicroyPthon banner so that it can be
sent to the host on initial connection of the USB serial port. This
buffering also works for when the CDC becomes disconnected and the device
is still printing to stdout, and when CDC is reconnected the most recent
part of stdout (depending on how big the internal USB FIFO is) is flushed
to the host.
This change is most obvious when you've first plugged in a MicroPython
device (or hit reset), when it's a board that uses USB (CDC) serial in the
chip itself for the REPL interface. This doesn't apply to UART going via a
separate USB-serial chip.
The stm32 port already has this buffering behaviour (it doesn't use
TinyUSB) and this commit extends such behaviour to rp2, mimxrt, samd and
renesas-ra ports, which do use TinyUSB.
Signed-off-by: Andrew Leech <andrew@alelec.net>
This fixes the build for some esp32 and nrf boards (for example
`ARDUINO_NANO_33_BLE_SENSE` and `ARDUINO_NANO_ESP32`) due to commit
c98789a6d8. Changes are:
- Allow the CDC TX/RX functions in `mp_usbd_cdc.c` to be enabled
separately to those needed for `MICROPY_HW_USB_CDC_1200BPS_TOUCH`.
- Add `MICROPY_EXCLUDE_SHARED_TINYUSB_USBD_CDC` option as a temporary
workaround for the nrf port to use.
- Declare `mp_usbd_line_state_cb()` in a header as a public function.
- Fix warning with type cast of `.callback_line_state_changed`.
Signed-off-by: Damien George <damien@micropython.org>
There are a few TinyUSB CDC functions used for stdio that are currently
replicated across a number of ports. Not surprisingly in a couple of cases
these have started to diverge slightly, with additional features added to
one of them.
This commit consolidates a couple of key shared functions used directly by
TinyUSB based ports, and makes those functions available to all.
Signed-off-by: Andrew Leech <andrew@alelec.net>