Serial Device Drivers

  • include/nuttx/serial/serial.h. All structures and APIs needed to work with serial drivers are provided in this header file.

  • struct uart_ops_s. Each serial device driver must implement an instance of struct uart_ops_s. That structure defines a call table with the following methods:

  • int uart_register(FAR const char *path, FAR uart_dev_t *dev);. A serial driver may register itself by calling uart_register(), passing it the path where it will appear in the pseudo file system and it’s initialized instance of struct uart_ops_s. By convention, serial device drivers are registered at paths like /dev/ttyS0, /dev/ttyS1, etc. See the uart_register() implementation in drivers/serial.c.

  • TTY_LAUNCH this depends on CONFIG_TTY_LAUNCH, this feature allow user launch a new program with a special char input.

    e.g. use ctrl+R to start a nuttx shell. e.g. use ctrl+E to start user entry.

    You can use TTY_LAUNCH_CHAR to customize which special char.

    You can choose launch method: TTY_LAUNCH_ENTRY or TTY_LAUNCH_FILE, If``TTY_LAUNCH_ENTRY`` you can set program entry by TTY_LAUNCH_ENTRYPOINT. If``TTY_LAUNCH_FILE`` you can set file path by TTY_LAUNCH_FILEPATH.


  • User Access. Serial drivers are, ultimately, normal character drivers and are accessed as other character drivers.

  • Examples: arch/arm/src/stm32/stm32_serial.c, arch/arm/src/lpc214x/lpc214x_serial.c, arch/z16/src/z16f/z16f_serial.c, etc.