Advanced Configuration and Power Interface Specification

ACPI Software Programming Model
OEM Table ID 8 16 An OEM-supplied string that the OEM uses to identify the particular
data table. This field is particularly useful when defining a definition
block to distinguish definition block functions. The OEM assigns
each dissimilar table a new OEM Table ID.
OEM Revision 4 24 An OEM-supplied revision number. Larger numbers are assumed to
be newer revisions.
Creator ID 4 28 Vendor ID of utility that created the table. For tables containing
Definition Blocks, this is the ID for the ASL Compiler.
Creator Revision 4 32 Revision of utility that created the table. For tables containing
Definition Blocks, this is the revision for the ASL Compiler.
For OEMs, good design practices will ensure consistency when assigning OEMID and OEM Table
ID fields in any table. The intent of these fields is to allow for a binary control system that support
services can use. Because many support functions can be automated, it is useful when a tool can
programmatically determine which table release is a compatible and more recent revision of a prior
table on the same OEMID and OEM Table ID.
Table 5-30 and Table 5-31 contain the system description table signatures defined by this
specification. These system description tables may be defined by ACPI and documented within this
specification (Table 5-30) or they may be simply reserved by ACPI and defined by other industry
specifications (Table 5-31). This allows OS and platform specific tables to be defined and pointed to
by the RSDT/XSDT as needed. For tables defined by other industry specifications, the ACPI
specification acts as gatekeeper to avoid collisions in table signatures.
Table signatures will be reserved by the ACPI promoters and posted independently of this
specification in ACPI errata and clarification documents on the ACPI web site. Requests to reserve a
4-byte alphanumeric table signature should be sent to the email address info@acpi.info and should
include the purpose of the table and reference URL to a document that describes the table format.
Tables defined outside of the ACPI specification may define data value encodings in either little
endian or big endian format. For the purpose of clarity, external table definition documents should
include the endian-ness of their data value encodings.
Since reference URLs can change over time and may not always be up-to-date in this specification, a
separate document containing the latest known reference URLs can be found at “Links to ACPI-
Related Documents” (http://uefi.org/acpi), which should conspicuously be placed in the same
location as this specification.
Table 5-30 DESCRIPTION_HEADER Signatures for tables defined by ACPI
Signature Description Reference
“APIC” Multiple APIC Description Table Section 5.2.12, “Multiple APIC Description Table”
“BERT” Boot Error Record Table Section 18.3.1, “Boot Error Source”
“BGRT” Boot Graphics Resource Table Section 5.2.22, “Boot Graphics Resource Table”
“CPEP”
“DSDT”
Corrected Platform Error Polling
Table
Differentiated System Description
Table
Section 5.2.18, “Corrected Platform Error Polling Table”
Section 5.2.11.1, “Differentiated System Description
Table”
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