The SFFDISK_DEVICE_COMMAND_DATA structure specifies the operation performed by an IOCTL_SFFDISK_DEVICE_COMMAND request.

typedef struct _SFFDISK_DEVICE_COMMAND_DATA {
  USHORT  HeaderSize;
  USHORT  Reserved;
  SFFDISK_DCMD  Command;
  USHORT  ProtocolArgumentSize;
  ULONG  DeviceDataBufferSize;
  ULONG_PTR  Information;
  UCHAR  Data[0];
} SFFDISK_DEVICE_COMMAND_DATA, *PSFFDISK_DEVICE_COMMAND_DATA;

Members

HeaderSize

The length, in bytes, of the header structure. The size does not include any data concatenated at the end. The caller should initialize this field to sizeof (SFFDISK_DEVICE_COMMAND_DATA).

Reserved

Reserved.

Command

Contains an enumeration value of type SFFDISK_DCMD that defines the type of operation. Typical operations include retrieval of the card’s security level, device commands, and locking (or unlocking) the interface channel as a preliminary action to a series of commands.

ProtocolArgumentSize

The length in bytes of the device command arguments that immediately follow this header structure. This data begins at the address indicated by the Data member. Device command arguments are specific to the protocol of the device.

DeviceDataBufferSize

Defines the length, in bytes, of the data transfer.

Information

On output, this member contains an operation-dependent status value.

Data

Buffer that contains the command arguments.

Comments

The following diagram indicates the layout of the data submitted with an IOCTL_SFFDISK_DEVICE_COMMAND request. The caller of this request stores this data at the location indicated by the Data member of the SFFDISK_DEVICE_COMMAND_DATA structure:

Format of Device Command Data

The format of the protocol arguments depends on the protocol that the device uses. For an SD storage device, the protocol arguments section will contain an SDCMD_DESCRIPTOR.

Requirements

Headers: Declared in Sffdisk.h. Include Sffdisk.h.

See Also

IOCTL_SFFDISK_DEVICE_COMMAND