20.1. Introduction

The Input/Output (I/O) Manager provides a well-defined mechanism for accessing device drivers and a structured methodology for organizing device drivers. The directives provided by the I/O Manager are:

• rtems_io_register_driver() - Registers and initializes the device with the specified device driver address table and device major number in the Device Driver Table.

• rtems_io_unregister_driver() - Removes a device driver specified by the device major number from the Device Driver Table.

• rtems_io_initialize() - Initializes the device specified by the device major and minor numbers.

• rtems_io_register_name() - Registers the device specified by the device major and minor numbers in the file system under the specified name.

• rtems_io_open() - Opens the device specified by the device major and minor numbers.

• rtems_io_close() - Closes the device specified by the device major and minor numbers.

• rtems_io_read() - Reads from the device specified by the device major and minor numbers.

• rtems_io_write() - Writes to the device specified by the device major and minor numbers.

• rtems_io_control() - Controls the device specified by the device major and minor numbers.