Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
}
// Update DWORD3 in the buffer
Store(CTRL,CDW3)
Return(Arg3)
} Else {
Or(CDW1,4,CDW1) // Unrecognized UUID
Return(Arg3)
}
} // End _OSC
} // End PCI0
6.2.12 _PRS (Possible Resource Settings)
This optional object evaluates to a byte stream that describes the possible resource settings for the
device. When describing a platform, specify a _PRS for all the configurable devices. Static (nonconfigurable)
devices do not specify a _PRS object. The information in this package is used by
OSPM to select a conflict-free resource allocation without user intervention. This method must not
reference any operation regions that have not been declared available by a _REG method.
The format of the data in a _PRS object follows the same format as the _CRS object (for more
information, see the _CRS object definition in Section 6.2.2, “_CRS (Current Resource Settings)”).
If the device is disabled when _PRS is called, it must remain disabled.
Arguments:
None
Return Value:
A Buffer containing a Resource Descriptor byte stream
6.2.13 _PRT (PCI Routing Table)
PCI interrupts are inherently non-hierarchical. PCI interrupt pins are wired to interrupt inputs of the
interrupt controllers. The _PRT object provides a mapping from PCI interrupt pins to the interrupt
inputs of the interrupt controllers. The _PRT object is required under all PCI root bridges. _PRT
evaluates to a package that contains a list of packages, each of which describes the mapping of a PCI
interrupt pin.
Arguments:
None
Return Value:
A Package containing variable-length list of PCI interrupt mapping packages, as described below
Note: The PCI function number in the Address field of the _PRT packages must be 0xFFFF, indicating
“any” function number or “all functions”.
The _PRT mapping packages have the fields listed in Table 6-180.
Table 6-180 Mapping Fields
Field Type Description
Address DWORD The address of the device (uses the same format as _ADR).
322 April, 2015 Version 6.0