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extendedFindPCICapability

Search configuration space for a PCI capability register.

Declaration

virtual UInt32 extendedFindPCICapability(
 UInt32 capabilityID,
 IOByteCount *offset = 0 );

Parameters

  • capabilityID:

    A PCI capability ID. PCI Express devices may support extended capabilities in config space starting at offset 0x100. To search this space, the ID passed should be the negated value of the PCI-SIG assigned ID for the extended capability.

  • offset:

    An optional in/out parameter to return the offset into config space where the capability was found, and to set the start point of the next search. Initialize the offset to zero before the first call to extendedFindPCICapability() and subsequent calls will find all capabilty blocks that may exist on the device with the same ID.

Return Value

The 32-bit value of the capability register if one was found, zero otherwise.

Overview

This method searches the device's config space for a PCI capability register matching the passed capability ID, if the device supports PCI capabilities.

See Also

Miscellaneous