Contents

ioRead32

Reads a 32-bit value from an I/O space aperture.

Declaration

virtual UInt32 ioRead32(
 UInt16 offset,
 IOMemoryMap *map = 0 );

Parameters

  • offset:

    An offset into a bus or device's I/O space aperture.

  • map:

    If the offset is relative to the beginning of a device's aperture, an IOMemoryMap object for that object should be passed in. Otherwise, passing zero will write the value relative to the beginning of the bus' I/O space.

Return Value

The value read in host byte order (big endian on PPC).

Overview

This method will read a 32-bit value from a 4 byte aligned offset in an I/O space aperture. If a map object is passed in, the value is read relative to it, otherwise to the value is read relative to the I/O space aperture for the bus. This function encapsulates the differences between architectures in generating I/O space operations. An eieio instruction is included on PPC.

See Also

Miscellaneous