Intel Extensible Firmware Interface - Manual (Page 581)

Protocols — USB Support
Version 1.10 12/01/02 14-41
Related Definitions
typedef enum {
EfiUsbDataIn,
EfiUsbDataOut,
EfiUsbNoData
} EFI_USB_DATA_DIRECTION;
//
// Error code for USB Transfer Results
//
#define
EFI_USB_NOERROR 0x0000
#define EFI_USB_ERR_NOTEXECUTE 0x0001
#define EFI_USB_ERR_STALL 0x0002
#define EFI_USB_ERR_BUFFER 0x0004
#define EFI_USB_ERR_BABBLE 0x0008
#define EFI_USB_ERR_NAK 0x0010
#define EFI_USB_ERR_CRC 0x0020
#define EFI_USB_ERR_TIMEOUT 0x0040
#define EFI_USB_ERR_BITSTUFF 0x0080
#define EFI_USB_ERR_SYSTEM 0x0100
typedef struct {
UINT8
RequestType;
UINT8 Request;
UINT16 Value;
UINT16 Index;
UINT16 Length;
} EFI_USB_DEVICE_REQUEST;
RequestType The field identifies the characteristics of the specific request.
Request This field specifies the particular request.
Value This field is used to pass a parameter to USB device that is specific
to the request.
Index This field is also used to pass a parameter to USB device that is
specific to the request.
Length This field specifies the length of the data transferred during the
second phase of the control transfer. If it is 0, then there is no data
phase in this transfer.