Advanced Configuration and Power Interface Specification

ACPI Software Programming Model
as many I/O SAPIC structures as I/O APIC structures and that every I/O APIC structure has a
corresponding I/O SAPIC structure (same APIC ID).
5.2.12.10 Local SAPIC Structure
The Processor local SAPIC structure is very similar to the processor local APIC structure. When
using the SAPIC interrupt model, each processor in the system is required to have a Processor Local
SAPIC record in the MADT, and a processor device object in the DSDT. 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, processors are not allowed to be added, removed,
nor can their SAPIC ID or Flags change. When a processor is not present, the Processor Local
SAPIC information is either not reported or flagged as disabled.
Table 5-56 Processor Local SAPIC Structure
Field
Byte
Length
Byte
Offset
Description
Type 1 0 7 Processor Local SAPIC structure
Length 1 1 Length of the Local SAPIC Structure in bytes.
ACPI Processor
ID
1 2 OSPM associates the Local SAPIC Structure with a processor
object declared in the namespace using the Processor statement
by matching the processor object’s ProcessorID value with this
field. The use of the Processor statement is deprecated. See the
compatibility note in Section 5.2.12.12, and Section 19.6.102,
“Processor (Declare Processor).”
Local SAPIC ID 1 3 The processor’s local SAPIC ID
Local SAPIC EID 1 4 The processor’s local SAPIC EID
Reserved 3 5 Reserved (must be set to zero)
Flags 4 8 Local SAPIC flags. See Table 5-48 for a description of this field.
ACPI Processor
UID Value
ACPI Processor
UID String
4 12 OSPM associates the Local SAPIC Structure with a processor
object declared in the namespace using the Device statement,
when the _UID child object of the processor device evaluates to a
numeric value, by matching the numeric value with this field.
>=1 16 OSPM associates the Local SAPIC Structure with a processor
object declared in the namespace using the Device statement,
when the _UID child object of the processor device evaluates to a
string, by matching the string with this field. This value is stored as a
null-terminated ASCII string.
5.2.12.11 Platform Interrupt Source Structure
The Platform Interrupt Source structure is used to communicate which I/O SAPIC interrupt inputs
are connected to the platform interrupt sources.
Platform Management Interrupts (PMIs) are used to invoke platform firmware to handle various
events (similar to SMI in IA-32). The Intel® Itanium TM architecture permits the I/O SAPIC to send a
vector value in the interrupt message of the PMI type. This value is specified in the I/O SAPIC
Vector field of the Platform Interrupt Sources Structure.
Version 6.0 145