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ACPI_EVAL_OUTPUT_BUFFER_V1 structure (acpiioct.h)

  • Article

The ACPI_EVAL_OUTPUT_BUFFER structure contains output arguments from an ACPI control method.

Syntax

typedef struct _ACPI_EVAL_OUTPUT_BUFFER_V1 {
  ULONG                   Signature;
  ULONG                   Length;
  ULONG                   Count;
  ACPI_METHOD_ARGUMENT_V1 Argument[ANYSIZE_ARRAY];
} ACPI_EVAL_OUTPUT_BUFFER_V1, ACPI_EVAL_OUTPUT_BUFFER, *PACPI_EVAL_OUTPUT_BUFFER;

Members

Signature

The signature of the output buffer, which must be set to ACPI_EVAL_OUTPUT_BUFFER_SIGNATURE.

Length

The size, in bytes, of the output buffer. This size includes the storage for the ACPI_EVAL_OUTPUT_BUFFER structure at the start of the output buffer, plus any additional storage that might be required for data in the Argument array that extends past the end of the ACPI_EVAL_OUTPUT_BUFFER structure.

Count

The number of ACPI_METHOD_ARGUMENT structures that the Argument array contains.

Argument[ANYSIZE_ARRAY]

An array of ACPI_METHOD_ARGUMENT structures. For more information, see Remarks.

Remarks

The following ACPI IOCTLs return output arguments from ACPI control methods in an ACPI_EVAL_OUTPUT_BUFFER structure:

IOCTL_ACPI_ASYNC_EVAL_METHOD

IOCTL_ACPI_ASYNC_EVAL_METHOD_EX

IOCTL_ACPI_EVAL_METHOD

IOCTL_ACPI_EVAL_METHOD_EX

Typically, the Argument member is the start of an array of one or more ACPI_METHOD_ARGUMENT structures. If the array contains more than one ACPI_METHOD_ARGUMENT structure, the additional structures follow the end of the ACPI_EVAL_OUTPUT_BUFFER structure. However, these ACPI_METHOD_ARGUMENT structures form a true array only if none of the DataLength members of these structures has a value greater than sizeof(ULONG). For some types of data, the DataLength value in one or more of these structures can be greater than sizeof(ULONG), in which case the offsets between adjacent ACPI_METHOD_ARGUMENT structures can vary.

For more information about how to use ACPI_EVAL_OUTPUT_BUFFER structures to retrieve output arguments from an ACPI control method, see Evaluating ACPI Control Methods.

Requirements

Requirement Value
Minimum supported client Available starting with Windows 2000.
Header acpiioct.h (include Acpiioct.h)

See also

ACPI_METHOD_ARGUMENT