ACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING_V1 structure

• 02/15/2018
• 2 minutes to read

The ACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING structure is used as input to an IOCTL_ACPI_EVAL_METHOD request and to an IOCTL_ACPI_ASYNC_EVAL_METHOD request. The structure supplies the name of a control method and an input argument that is an ASCII string.

Syntax

typedef struct _ACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING_V1 {
  ULONG Signature;
  union {
    UCHAR MethodName[4];
    ULONG MethodNameAsUlong;
  } DUMMYUNIONNAME;
  ULONG StringLength;
  UCHAR String[ANYSIZE_ARRAY];
} ACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING_V1, *PACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING_V1, ACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING, *PACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING;

Members

Signature

The signature of a string input buffer, which must be set to ACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING_SIGNATURE.

DUMMYUNIONNAME

DUMMYUNIONNAME.MethodName

This union member is a four-element ASCII character array that contains the name of the method. For example, 'ABCD.'

DUMMYUNIONNAME.MethodNameAsUlong

This union member is a ULONG-typed variable that contains the name of the method in the format (ULONG) ('DCBA'), where the method name is the four-element ASCII character array 'ABCD.'

StringLength

The number of ASCII characters in the array of characters that is supplied by String.

String

An ASCII character string that contains the number of characters that is specified by StringLength. The string does not include a NULL terminator.

Remarks

If a device supports a control method named ABCD that takes an ASCII string as input, a driver for the device can evaluate the method by sending an IOCTL_ACPI_EVAL_METHOD request or an IOCTL_ACPI_ASYNC_EVAL_METHOD request to the device and setting the members of the input ACPI_EVAL_INPUT_BUFFER structure as follows:

• Set Signature to ACPI_EVAL_INPUT_BUFFER_SIMPLE_STRING_SIGNATURE.
• Set MethodName to 'ABCD' or MethodNameAsUlong to (ULONG)('DCBA').
• Set StringLength to the number of characters that is supplied by String.
• Set String to the input string.

Requirements

See Also

IOCTL_ACPI_ASYNC_EVAL_METHOD

IOCTL_ACPI_EVAL_METHOD