mirror of https://gitee.com/openkylin/linux.git
623 lines
26 KiB
Plaintext
623 lines
26 KiB
Plaintext
ACPI Tables
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-----------
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The expectations of individual ACPI tables are discussed in the list that
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follows.
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If a section number is used, it refers to a section number in the ACPI
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specification where the object is defined. If "Signature Reserved" is used,
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the table signature (the first four bytes of the table) is the only portion
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of the table recognized by the specification, and the actual table is defined
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outside of the UEFI Forum (see Section 5.2.6 of the specification).
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For ACPI on arm64, tables also fall into the following categories:
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-- Required: DSDT, FADT, GTDT, MADT, MCFG, RSDP, SPCR, XSDT
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-- Recommended: BERT, EINJ, ERST, HEST, PCCT, SSDT
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-- Optional: BGRT, CPEP, CSRT, DBG2, DRTM, ECDT, FACS, FPDT, IORT,
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MCHI, MPST, MSCT, NFIT, PMTT, RASF, SBST, SLIT, SPMI, SRAT, STAO,
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TCPA, TPM2, UEFI, XENV
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-- Not supported: BOOT, DBGP, DMAR, ETDT, HPET, IBFT, IVRS, LPIT,
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MSDM, OEMx, PSDT, RSDT, SLIC, WAET, WDAT, WDRT, WPBT
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Table Usage for ARMv8 Linux
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----- ----------------------------------------------------------------
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BERT Section 18.3 (signature == "BERT")
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== Boot Error Record Table ==
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Must be supplied if RAS support is provided by the platform. It
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is recommended this table be supplied.
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BOOT Signature Reserved (signature == "BOOT")
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== simple BOOT flag table ==
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Microsoft only table, will not be supported.
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BGRT Section 5.2.22 (signature == "BGRT")
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== Boot Graphics Resource Table ==
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Optional, not currently supported, with no real use-case for an
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ARM server.
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CPEP Section 5.2.18 (signature == "CPEP")
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== Corrected Platform Error Polling table ==
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Optional, not currently supported, and not recommended until such
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time as ARM-compatible hardware is available, and the specification
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suitably modified.
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CSRT Signature Reserved (signature == "CSRT")
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== Core System Resources Table ==
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Optional, not currently supported.
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DBG2 Signature Reserved (signature == "DBG2")
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== DeBuG port table 2 ==
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License has changed and should be usable. Optional if used instead
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of earlycon=<device> on the command line.
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DBGP Signature Reserved (signature == "DBGP")
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== DeBuG Port table ==
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Microsoft only table, will not be supported.
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DSDT Section 5.2.11.1 (signature == "DSDT")
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== Differentiated System Description Table ==
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A DSDT is required; see also SSDT.
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ACPI tables contain only one DSDT but can contain one or more SSDTs,
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which are optional. Each SSDT can only add to the ACPI namespace,
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but cannot modify or replace anything in the DSDT.
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DMAR Signature Reserved (signature == "DMAR")
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== DMA Remapping table ==
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x86 only table, will not be supported.
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DRTM Signature Reserved (signature == "DRTM")
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== Dynamic Root of Trust for Measurement table ==
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Optional, not currently supported.
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ECDT Section 5.2.16 (signature == "ECDT")
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== Embedded Controller Description Table ==
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Optional, not currently supported, but could be used on ARM if and
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only if one uses the GPE_BIT field to represent an IRQ number, since
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there are no GPE blocks defined in hardware reduced mode. This would
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need to be modified in the ACPI specification.
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EINJ Section 18.6 (signature == "EINJ")
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== Error Injection table ==
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This table is very useful for testing platform response to error
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conditions; it allows one to inject an error into the system as
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if it had actually occurred. However, this table should not be
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shipped with a production system; it should be dynamically loaded
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and executed with the ACPICA tools only during testing.
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ERST Section 18.5 (signature == "ERST")
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== Error Record Serialization Table ==
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On a platform supports RAS, this table must be supplied if it is not
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UEFI-based; if it is UEFI-based, this table may be supplied. When this
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table is not present, UEFI run time service will be utilized to save
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and retrieve hardware error information to and from a persistent store.
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ETDT Signature Reserved (signature == "ETDT")
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== Event Timer Description Table ==
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Obsolete table, will not be supported.
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FACS Section 5.2.10 (signature == "FACS")
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== Firmware ACPI Control Structure ==
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It is unlikely that this table will be terribly useful. If it is
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provided, the Global Lock will NOT be used since it is not part of
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the hardware reduced profile, and only 64-bit address fields will
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be considered valid.
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FADT Section 5.2.9 (signature == "FACP")
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== Fixed ACPI Description Table ==
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Required for arm64.
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The HW_REDUCED_ACPI flag must be set. All of the fields that are
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to be ignored when HW_REDUCED_ACPI is set are expected to be set to
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zero.
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If an FACS table is provided, the X_FIRMWARE_CTRL field is to be
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used, not FIRMWARE_CTRL.
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If PSCI is used (as is recommended), make sure that ARM_BOOT_ARCH is
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filled in properly -- that the PSCI_COMPLIANT flag is set and that
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PSCI_USE_HVC is set or unset as needed (see table 5-37).
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For the DSDT that is also required, the X_DSDT field is to be used,
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not the DSDT field.
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FPDT Section 5.2.23 (signature == "FPDT")
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== Firmware Performance Data Table ==
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Optional, not currently supported.
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GTDT Section 5.2.24 (signature == "GTDT")
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== Generic Timer Description Table ==
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Required for arm64.
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HEST Section 18.3.2 (signature == "HEST")
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== Hardware Error Source Table ==
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ARM-specific error sources have been defined; please use those or the
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PCI types such as type 6 (AER Root Port), 7 (AER Endpoint), or 8 (AER
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Bridge), or use type 9 (Generic Hardware Error Source). Firmware first
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error handling is possible if and only if Trusted Firmware is being
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used on arm64.
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Must be supplied if RAS support is provided by the platform. It
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is recommended this table be supplied.
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HPET Signature Reserved (signature == "HPET")
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== High Precision Event timer Table ==
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x86 only table, will not be supported.
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IBFT Signature Reserved (signature == "IBFT")
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== iSCSI Boot Firmware Table ==
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Microsoft defined table, support TBD.
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IORT Signature Reserved (signature == "IORT")
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== Input Output Remapping Table ==
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arm64 only table, required in order to describe IO topology, SMMUs,
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and GIC ITSs, and how those various components are connected together,
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such as identifying which components are behind which SMMUs/ITSs.
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This table will only be required on certain SBSA platforms (e.g.,
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when using GICv3-ITS and an SMMU); on SBSA Level 0 platforms, it
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remains optional.
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IVRS Signature Reserved (signature == "IVRS")
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== I/O Virtualization Reporting Structure ==
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x86_64 (AMD) only table, will not be supported.
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LPIT Signature Reserved (signature == "LPIT")
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== Low Power Idle Table ==
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x86 only table as of ACPI 5.1; starting with ACPI 6.0, processor
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descriptions and power states on ARM platforms should use the DSDT
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and define processor container devices (_HID ACPI0010, Section 8.4,
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and more specifically 8.4.3 and and 8.4.4).
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MADT Section 5.2.12 (signature == "APIC")
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== Multiple APIC Description Table ==
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Required for arm64. Only the GIC interrupt controller structures
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should be used (types 0xA - 0xF).
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MCFG Signature Reserved (signature == "MCFG")
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== Memory-mapped ConFiGuration space ==
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If the platform supports PCI/PCIe, an MCFG table is required.
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MCHI Signature Reserved (signature == "MCHI")
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== Management Controller Host Interface table ==
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Optional, not currently supported.
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MPST Section 5.2.21 (signature == "MPST")
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== Memory Power State Table ==
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Optional, not currently supported.
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MSCT Section 5.2.19 (signature == "MSCT")
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== Maximum System Characteristic Table ==
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Optional, not currently supported.
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MSDM Signature Reserved (signature == "MSDM")
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== Microsoft Data Management table ==
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Microsoft only table, will not be supported.
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NFIT Section 5.2.25 (signature == "NFIT")
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== NVDIMM Firmware Interface Table ==
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Optional, not currently supported.
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OEMx Signature of "OEMx" only
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== OEM Specific Tables ==
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All tables starting with a signature of "OEM" are reserved for OEM
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use. Since these are not meant to be of general use but are limited
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to very specific end users, they are not recommended for use and are
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not supported by the kernel for arm64.
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PCCT Section 14.1 (signature == "PCCT)
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== Platform Communications Channel Table ==
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Recommend for use on arm64; use of PCC is recommended when using CPPC
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to control performance and power for platform processors.
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PMTT Section 5.2.21.12 (signature == "PMTT")
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== Platform Memory Topology Table ==
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Optional, not currently supported.
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PSDT Section 5.2.11.3 (signature == "PSDT")
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== Persistent System Description Table ==
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Obsolete table, will not be supported.
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RASF Section 5.2.20 (signature == "RASF")
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== RAS Feature table ==
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Optional, not currently supported.
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RSDP Section 5.2.5 (signature == "RSD PTR")
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== Root System Description PoinTeR ==
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Required for arm64.
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RSDT Section 5.2.7 (signature == "RSDT")
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== Root System Description Table ==
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Since this table can only provide 32-bit addresses, it is deprecated
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on arm64, and will not be used. If provided, it will be ignored.
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SBST Section 5.2.14 (signature == "SBST")
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== Smart Battery Subsystem Table ==
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Optional, not currently supported.
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SLIC Signature Reserved (signature == "SLIC")
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== Software LIcensing table ==
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Microsoft only table, will not be supported.
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SLIT Section 5.2.17 (signature == "SLIT")
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== System Locality distance Information Table ==
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Optional in general, but required for NUMA systems.
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SPCR Signature Reserved (signature == "SPCR")
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== Serial Port Console Redirection table ==
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Required for arm64.
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SPMI Signature Reserved (signature == "SPMI")
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== Server Platform Management Interface table ==
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Optional, not currently supported.
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SRAT Section 5.2.16 (signature == "SRAT")
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== System Resource Affinity Table ==
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Optional, but if used, only the GICC Affinity structures are read.
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To support arm64 NUMA, this table is required.
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SSDT Section 5.2.11.2 (signature == "SSDT")
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== Secondary System Description Table ==
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These tables are a continuation of the DSDT; these are recommended
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for use with devices that can be added to a running system, but can
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also serve the purpose of dividing up device descriptions into more
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manageable pieces.
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An SSDT can only ADD to the ACPI namespace. It cannot modify or
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replace existing device descriptions already in the namespace.
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These tables are optional, however. ACPI tables should contain only
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one DSDT but can contain many SSDTs.
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STAO Signature Reserved (signature == "STAO")
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== _STA Override table ==
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Optional, but only necessary in virtualized environments in order to
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hide devices from guest OSs.
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TCPA Signature Reserved (signature == "TCPA")
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== Trusted Computing Platform Alliance table ==
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Optional, not currently supported, and may need changes to fully
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interoperate with arm64.
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TPM2 Signature Reserved (signature == "TPM2")
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== Trusted Platform Module 2 table ==
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Optional, not currently supported, and may need changes to fully
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interoperate with arm64.
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UEFI Signature Reserved (signature == "UEFI")
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== UEFI ACPI data table ==
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Optional, not currently supported. No known use case for arm64,
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at present.
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WAET Signature Reserved (signature == "WAET")
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== Windows ACPI Emulated devices Table ==
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Microsoft only table, will not be supported.
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WDAT Signature Reserved (signature == "WDAT")
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== Watch Dog Action Table ==
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Microsoft only table, will not be supported.
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WDRT Signature Reserved (signature == "WDRT")
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== Watch Dog Resource Table ==
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Microsoft only table, will not be supported.
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WPBT Signature Reserved (signature == "WPBT")
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== Windows Platform Binary Table ==
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Microsoft only table, will not be supported.
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XENV Signature Reserved (signature == "XENV")
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== Xen project table ==
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Optional, used only by Xen at present.
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XSDT Section 5.2.8 (signature == "XSDT")
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== eXtended System Description Table ==
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Required for arm64.
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ACPI Objects
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------------
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The expectations on individual ACPI objects that are likely to be used are
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shown in the list that follows; any object not explicitly mentioned below
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should be used as needed for a particular platform or particular subsystem,
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such as power management or PCI.
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Name Section Usage for ARMv8 Linux
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---- ------------ -------------------------------------------------
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_CCA 6.2.17 This method must be defined for all bus masters
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on arm64 -- there are no assumptions made about
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whether such devices are cache coherent or not.
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The _CCA value is inherited by all descendants of
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these devices so it does not need to be repeated.
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Without _CCA on arm64, the kernel does not know what
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to do about setting up DMA for the device.
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NB: this method provides default cache coherency
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attributes; the presence of an SMMU can be used to
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modify that, however. For example, a master could
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default to non-coherent, but be made coherent with
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the appropriate SMMU configuration (see Table 17 of
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the IORT specification, ARM Document DEN 0049B).
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_CID 6.1.2 Use as needed, see also _HID.
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_CLS 6.1.3 Use as needed, see also _HID.
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_CPC 8.4.7.1 Use as needed, power management specific. CPPC is
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recommended on arm64.
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_CRS 6.2.2 Required on arm64.
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_CSD 8.4.2.2 Use as needed, used only in conjunction with _CST.
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_CST 8.4.2.1 Low power idle states (8.4.4) are recommended instead
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of C-states.
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_DDN 6.1.4 This field can be used for a device name. However,
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it is meant for DOS device names (e.g., COM1), so be
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careful of its use across OSes.
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_DSD 6.2.5 To be used with caution. If this object is used, try
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to use it within the constraints already defined by the
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Device Properties UUID. Only in rare circumstances
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should it be necessary to create a new _DSD UUID.
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In either case, submit the _DSD definition along with
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any driver patches for discussion, especially when
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device properties are used. A driver will not be
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considered complete without a corresponding _DSD
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description. Once approved by kernel maintainers,
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the UUID or device properties must then be registered
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with the UEFI Forum; this may cause some iteration as
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more than one OS will be registering entries.
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_DSM 9.1.1 Do not use this method. It is not standardized, the
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return values are not well documented, and it is
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currently a frequent source of error.
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\_GL 5.7.1 This object is not to be used in hardware reduced
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mode, and therefore should not be used on arm64.
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_GLK 6.5.7 This object requires a global lock be defined; there
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is no global lock on arm64 since it runs in hardware
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reduced mode. Hence, do not use this object on arm64.
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\_GPE 5.3.1 This namespace is for x86 use only. Do not use it
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on arm64.
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_HID 6.1.5 This is the primary object to use in device probing,
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though _CID and _CLS may also be used.
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_INI 6.5.1 Not required, but can be useful in setting up devices
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when UEFI leaves them in a state that may not be what
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the driver expects before it starts probing.
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_LPI 8.4.4.3 Recommended for use with processor definitions (_HID
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ACPI0010) on arm64. See also _RDI.
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_MLS 6.1.7 Highly recommended for use in internationalization.
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_OFF 7.2.2 It is recommended to define this method for any device
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that can be turned on or off.
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_ON 7.2.3 It is recommended to define this method for any device
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that can be turned on or off.
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\_OS 5.7.3 This method will return "Linux" by default (this is
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the value of the macro ACPI_OS_NAME on Linux). The
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command line parameter acpi_os=<string> can be used
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to set it to some other value.
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_OSC 6.2.11 This method can be a global method in ACPI (i.e.,
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\_SB._OSC), or it may be associated with a specific
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device (e.g., \_SB.DEV0._OSC), or both. When used
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as a global method, only capabilities published in
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the ACPI specification are allowed. When used as
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a device-specific method, the process described for
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using _DSD MUST be used to create an _OSC definition;
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out-of-process use of _OSC is not allowed. That is,
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submit the device-specific _OSC usage description as
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part of the kernel driver submission, get it approved
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by the kernel community, then register it with the
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UEFI Forum.
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\_OSI 5.7.2 Deprecated on ARM64. As far as ACPI firmware is
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concerned, _OSI is not to be used to determine what
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sort of system is being used or what functionality
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is provided. The _OSC method is to be used instead.
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_PDC 8.4.1 Deprecated, do not use on arm64.
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\_PIC 5.8.1 The method should not be used. On arm64, the only
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interrupt model available is GIC.
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\_PR 5.3.1 This namespace is for x86 use only on legacy systems.
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Do not use it on arm64.
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_PRT 6.2.13 Required as part of the definition of all PCI root
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devices.
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_PRx 7.3.8-11 Use as needed; power management specific. If _PR0 is
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defined, _PR3 must also be defined.
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_PSx 7.3.2-5 Use as needed; power management specific. If _PS0 is
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defined, _PS3 must also be defined. If clocks or
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regulators need adjusting to be consistent with power
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usage, change them in these methods.
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_RDI 8.4.4.4 Recommended for use with processor definitions (_HID
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ACPI0010) on arm64. This should only be used in
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conjunction with _LPI.
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\_REV 5.7.4 Always returns the latest version of ACPI supported.
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\_SB 5.3.1 Required on arm64; all devices must be defined in this
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namespace.
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_SLI 6.2.15 Use is recommended when SLIT table is in use.
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_STA 6.3.7, It is recommended to define this method for any device
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7.2.4 that can be turned on or off. See also the STAO table
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that provides overrides to hide devices in virtualized
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environments.
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_SRS 6.2.16 Use as needed; see also _PRS.
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_STR 6.1.10 Recommended for conveying device names to end users;
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this is preferred over using _DDN.
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_SUB 6.1.9 Use as needed; _HID or _CID are preferred.
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_SUN 6.1.11 Use as needed, but recommended.
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_SWS 7.4.3 Use as needed; power management specific; this may
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require specification changes for use on arm64.
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_UID 6.1.12 Recommended for distinguishing devices of the same
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class; define it if at all possible.
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ACPI Event Model
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----------------
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Do not use GPE block devices; these are not supported in the hardware reduced
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profile used by arm64. Since there are no GPE blocks defined for use on ARM
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platforms, ACPI events must be signaled differently.
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There are two options: GPIO-signaled interrupts (Section 5.6.5), and
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interrupt-signaled events (Section 5.6.9). Interrupt-signaled events are a
|
|
new feature in the ACPI 6.1 specification. Either -- or both -- can be used
|
|
on a given platform, and which to use may be dependent of limitations in any
|
|
given SoC. If possible, interrupt-signaled events are recommended.
|
|
|
|
|
|
ACPI Processor Control
|
|
----------------------
|
|
Section 8 of the ACPI specification changed significantly in version 6.0.
|
|
Processors should now be defined as Device objects with _HID ACPI0007; do
|
|
not use the deprecated Processor statement in ASL. All multiprocessor systems
|
|
should also define a hierarchy of processors, done with Processor Container
|
|
Devices (see Section 8.4.3.1, _HID ACPI0010); do not use processor aggregator
|
|
devices (Section 8.5) to describe processor topology. Section 8.4 of the
|
|
specification describes the semantics of these object definitions and how
|
|
they interrelate.
|
|
|
|
Most importantly, the processor hierarchy defined also defines the low power
|
|
idle states that are available to the platform, along with the rules for
|
|
determining which processors can be turned on or off and the circumstances
|
|
that control that. Without this information, the processors will run in
|
|
whatever power state they were left in by UEFI.
|
|
|
|
Note too, that the processor Device objects defined and the entries in the
|
|
MADT for GICs are expected to be in synchronization. The _UID of the Device
|
|
object must correspond to processor IDs used in the MADT.
|
|
|
|
It is recommended that CPPC (8.4.5) be used as the primary model for processor
|
|
performance control on arm64. C-states and P-states may become available at
|
|
some point in the future, but most current design work appears to favor CPPC.
|
|
|
|
Further, it is essential that the ARMv8 SoC provide a fully functional
|
|
implementation of PSCI; this will be the only mechanism supported by ACPI
|
|
to control CPU power state. Booting of secondary CPUs using the ACPI
|
|
parking protocol is possible, but discouraged, since only PSCI is supported
|
|
for ARM servers.
|
|
|
|
|
|
ACPI System Address Map Interfaces
|
|
----------------------------------
|
|
In Section 15 of the ACPI specification, several methods are mentioned as
|
|
possible mechanisms for conveying memory resource information to the kernel.
|
|
For arm64, we will only support UEFI for booting with ACPI, hence the UEFI
|
|
GetMemoryMap() boot service is the only mechanism that will be used.
|
|
|
|
|
|
ACPI Platform Error Interfaces (APEI)
|
|
-------------------------------------
|
|
The APEI tables supported are described above.
|
|
|
|
APEI requires the equivalent of an SCI and an NMI on ARMv8. The SCI is used
|
|
to notify the OSPM of errors that have occurred but can be corrected and the
|
|
system can continue correct operation, even if possibly degraded. The NMI is
|
|
used to indicate fatal errors that cannot be corrected, and require immediate
|
|
attention.
|
|
|
|
Since there is no direct equivalent of the x86 SCI or NMI, arm64 handles
|
|
these slightly differently. The SCI is handled as a high priority interrupt;
|
|
given that these are corrected (or correctable) errors being reported, this
|
|
is sufficient. The NMI is emulated as the highest priority interrupt
|
|
possible. This implies some caution must be used since there could be
|
|
interrupts at higher privilege levels or even interrupts at the same priority
|
|
as the emulated NMI. In Linux, this should not be the case but one should
|
|
be aware it could happen.
|
|
|
|
|
|
ACPI Objects Not Supported on ARM64
|
|
-----------------------------------
|
|
While this may change in the future, there are several classes of objects
|
|
that can be defined, but are not currently of general interest to ARM servers.
|
|
Some of these objects have x86 equivalents, and may actually make sense in ARM
|
|
servers. However, there is either no hardware available at present, or there
|
|
may not even be a non-ARM implementation yet. Hence, they are not currently
|
|
supported.
|
|
|
|
The following classes of objects are not supported:
|
|
|
|
-- Section 9.2: ambient light sensor devices
|
|
|
|
-- Section 9.3: battery devices
|
|
|
|
-- Section 9.4: lids (e.g., laptop lids)
|
|
|
|
-- Section 9.8.2: IDE controllers
|
|
|
|
-- Section 9.9: floppy controllers
|
|
|
|
-- Section 9.10: GPE block devices
|
|
|
|
-- Section 9.15: PC/AT RTC/CMOS devices
|
|
|
|
-- Section 9.16: user presence detection devices
|
|
|
|
-- Section 9.17: I/O APIC devices; all GICs must be enumerable via MADT
|
|
|
|
-- Section 9.18: time and alarm devices (see 9.15)
|
|
|
|
-- Section 10: power source and power meter devices
|
|
|
|
-- Section 11: thermal management
|
|
|
|
-- Section 12: embedded controllers interface
|
|
|
|
-- Section 13: SMBus interfaces
|
|
|
|
|
|
This also means that there is no support for the following objects:
|
|
|
|
Name Section Name Section
|
|
---- ------------ ---- ------------
|
|
_ALC 9.3.4 _FDM 9.10.3
|
|
_ALI 9.3.2 _FIX 6.2.7
|
|
_ALP 9.3.6 _GAI 10.4.5
|
|
_ALR 9.3.5 _GHL 10.4.7
|
|
_ALT 9.3.3 _GTM 9.9.2.1.1
|
|
_BCT 10.2.2.10 _LID 9.5.1
|
|
_BDN 6.5.3 _PAI 10.4.4
|
|
_BIF 10.2.2.1 _PCL 10.3.2
|
|
_BIX 10.2.2.1 _PIF 10.3.3
|
|
_BLT 9.2.3 _PMC 10.4.1
|
|
_BMA 10.2.2.4 _PMD 10.4.8
|
|
_BMC 10.2.2.12 _PMM 10.4.3
|
|
_BMD 10.2.2.11 _PRL 10.3.4
|
|
_BMS 10.2.2.5 _PSR 10.3.1
|
|
_BST 10.2.2.6 _PTP 10.4.2
|
|
_BTH 10.2.2.7 _SBS 10.1.3
|
|
_BTM 10.2.2.9 _SHL 10.4.6
|
|
_BTP 10.2.2.8 _STM 9.9.2.1.1
|
|
_DCK 6.5.2 _UPD 9.16.1
|
|
_EC 12.12 _UPP 9.16.2
|
|
_FDE 9.10.1 _WPC 10.5.2
|
|
_FDI 9.10.2 _WPP 10.5.3
|
|
|