ReadIoSpaceEx function

Description

The ReadIoSpaceEx function is an extended version of ReadIoSpace. It reads not only the system I/O locations, but also I/O locations on a bus. ReadIoSpace works like ReadIoSpaceEx, except that it defaults interfacetype to ISA, busnumber to zero, and addressspace to 1.

Parameters

address

Specifies the I/O address to read from.

data

Specifies the address of a variable to hold the data read. This must be at least the number of bytes contained in size.

size

Specifies the address of a variable that contains the number of bytes to read. Size must be 1, 2, or 4. After the data is read, size will contain the number of bytes actually read.

interfacetype

Specifies the type of interface on which the extended I/O space exists. Possible values include ISA, EISA, and MCA. For more information, see ntddk.h, which is available as part of Windows Driver Kit.

busnumber

Specifies the number of the bus on which the extended I/O space exists. This is typically zero, unless there is more than one bus of a given type.

addressspace

This is typically 1.

Remarks

If you are writing 64-bit code, you should use ReadIoSpaceEx64 instead. See 32-Bit Pointers and 64-Bit Pointers for details.

If you are writing a WdbgExts extension, include wdbgexts.h. If you are writing a DbgEng extension that calls this function, include wdbgexts.h before dbgeng.h (see Writing DbgEng Extension Code for details).