Advanced Configuration and Power Interface Specification

ACPI Software Programming Model
Table 5-58 Platform Interrupt Source Flags
Platform
Interrupt Source
Flags
CPEI Processor
Override
Bit
Length
Bit
Offset
Description
1 0 When set, indicates that retrieval of error information is allowed
from any processor and OSPM is to use the information provided
by the processor ID, EID fields of the Platform Interrupt Source
Structure (Table 5-57) as a target processor hint.
Reserved 31 1 Must be zero.
5.2.12.12 Processor Local x2APIC Structure
The Processor X2APIC structure is very similar to the processor local APIC structure. When using
the X2APIC interrupt model, logical processors are required to have a processor device object in the
DSDT and must convey the processor's APIC information to OSPM using the Processor Local
X2APIC structure.
Note: [Compatibility note] On some legacy OSes, Logical processors with APIC ID values less than 255
(whether in XAPIC or X2APIC mode) must use the Processor Local APIC structure to convey their
APIC information to OSPM, and those processors must be declared in the DSDT using the
Processor() keyword. Logical processors with APIC ID values 255 and greater must use the
Processor Local x2APIC structure and be declared using the Device() keyword. See
Section 19.6.102 "Processor (Declare Processor)" for more information.
OSPM does not expect the information provided in this table to be updated if the processor
information changes during the lifespan of an OS boot. While in the sleeping state, logical
processors must not be added or removed, nor can their X2APIC ID or x2APIC Flags change. When
a logical processor is not present, the processor local X2APIC information is either not reported or
flagged as disabled.
The format of x2APIC structure is listed in Table 5-59.
Table 5-59 Processor Local x2APIC Structure
Field
Byte
Length
Byte
Offset
Description
Type 1 0 9 Processor Local x2APIC structure
Length 1 1 16
Reserved 2 2 Reserved - Must be zero
X2APIC ID 4 4 The processor’s local x2APIC ID.
Flags 4 8 Same as Local APIC flags. See Table 5-47 for a description of this
field.
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