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RTEMS 4.9.3 On-Line Library


I/O Manager IO_READ - Read from a device

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16.4.8: IO_READ - Read from a device

CALLING SEQUENCE:

rtems_status_code rtems_io_read(
  rtems_device_major_number  major,
  rtems_device_minor_number  minor,
  void                      *argument
);

DIRECTIVE STATUS CODES:

RTEMS_SUCCESSFUL - successfully initialized
RTEMS_INVALID_NUMBER - invalid major device number

DESCRIPTION:

This directive calls the device driver read routine specified in the Device Driver Table for this major number. Read operations typically require a buffer address as part of the argument parameter block. The contents of this buffer will be replaced with data from the device.

NOTES:

This directive may or may not cause the calling task to be preempted. This is dependent on the device driver being invoked.


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