Advanced Configuration and Power Interface Specification

ACPI Software Programming Model
Field
Byte
Length
Byte
Offset
Description
Flags 4 16 GIC MSI Frame Flags. See Table 5-65
SPI Count 2 20 SPI Count used by this frame. Unless the SPI Count Select flag is
set to 1 this value should match the lower 16 bits of the
MSI_TYPER register in the frame.
SPI Base 2 22 SPI Base used by this frame. Unless the SPI Base Select flag is
set to 1 this value should match the upper 16 bits of the
MSI_TYPER register in the frame.
Table 5-65 GIC MSI Frame Flags
GIC MSI Frame
Flags
SPI Count/Base
Select
Bit
Length
Bit
Offset
Description
1 0 0: The SPI Count and Base fields should be ignored, and the
actual values should be queried from the MSI_TYPER register in
the associated GIC MSI frame.
1: The SPI Count and Base values override the values specified in
the MSI_TYPER register in the associated GIC MSI frame.
Reserved 31 1 Must be zero.
5.2.12.17 GICR Structure
The GICR Structure is described in Table 5-69. This structure enables the discovery of GIC
Redistributor base addresses by providing the Physical Base Address of a page range containing the
GIC Redistributors. More than one GICR Structure may be presented in the MADT. GICR
structures should only be used when describing GIC implementations which conform to version 3 or
higher of the GIC architecture and which place all Redistributors in the always-on power domain.
Table 5-66 GIC Redistributor Structure
Field
Byte
Length
Byte
Offset
Description
Type 1 0 0xE GIC Redistributor structure
Length 1 1 16
Reserved 2 2 Reserved - Must be zero
Discovery Range
Base Address
Discovery Range
Length
8 4 The 64-bit physical address of a page range containing all GIC
Redistributors
4 12 Length of the GIC Redistributor Discovery page range.
5.2.12.18 GIC ITS Structure
The GIC Interrupt Translation Service is optionally supported in GICv3/v4 implementations. The
format of the GIC Translation Service Structure is listed below:
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