HP/HPE USB Device Correlation Record (Type 239)

Source: dmidecode, dmioem.c. No dumps of the data corpus hold the structure.

Describes a USB device the firmware has found at boot on a USB port (type 238), and the UEFI boot entries naming it. Devices plugged in later are not described. The structure is decoded from Gen9 onwards, UEFI firmware only.

Table 1. HP/HPE USB Device Correlation Record structure
Offset	Version	Name	Length	Value	Description
`0x00`	2.0+	Type	`BYTE`	`239`	HP/HPE USB Device Correlation Record indicator
`0x01`	2.0+	Length	`BYTE`	`0x17`	Length of the structure
`0x02`	2.0+	Handle	`WORD`	Varies
`0x04`	2.0+	USB Port Handle	`WORD`	`HANDLE`	Handle of the USB port connector correlation record (type 238)
`0x06`	2.0+	Vendor ID	`WORD`	`NUMBER`	USB vendor ID
`0x08`	2.0+	Flags	`WORD`	`BITFIELD`	Bit 0: an embedded SD card is present
`0x0A`	2.0+	Class	`BYTE`	`NUMBER`	USB class code
`0x0B`	2.0+	Subclass	`BYTE`	`NUMBER`	USB subclass code, see Mass storage subclasses for the mass storage class (`0x08`)
`0x0C`	2.0+	Protocol	`BYTE`	`NUMBER`	USB protocol code, see Mass storage protocols for the mass storage class (`0x08`) and Hub protocols for the hub class (`0x09`)
`0x0D`	2.0+	Product ID	`WORD`	`NUMBER`	USB product ID
`0x0F`	2.0+	Capacity	`DWORD`	`NUMBER`	Capacity in megabytes, zero if not applicable
`0x13`	2.0+	UEFI Device Path	`BYTE`	`STRING`
`0x14`	2.0+	UEFI Device Structured Name	`BYTE`	`STRING`
`0x15`	2.0+	Device Name	`BYTE`	`STRING`
`0x16`	2.0+	Location	`BYTE`	`STRING`

The codes are the ones the USB Implementers Forum defines for the classes, named the way dmidecode names them. The codes of the other classes are shown as they are.

Table 2. Mass storage subclass
Value	Meaning
`0x00`	SCSI command set not reported
`0x01`	Reduced block commands (RBC)
`0x02`	ATAPI
`0x03`	QIC-157, obsolete
`0x04`	USB floppy interface (UFI)
`0x05`	SFF-8070i, obsolete
`0x06`	SCSI transparent command set
`0x07`	LSD FS
`0x08`	IEEE 1667
`0xFF`	Vendor-specific

Subclasses 0x09 to 0xFE are reserved.

Table 3. Mass storage protocol
Value	Meaning
`0x00`	Control/bulk/interrupt transport with command completion interrupt
`0x01`	Control/bulk/interrupt transport without command completion interrupt
`0x02`	Obsolete
`0x50`	Bulk-only transport
`0x62`	USB attached SCSI (UAS)
`0xFF`	Vendor-specific

Table 4. Hub protocol
Value	Meaning
`0x00`	Full speed
`0x01`	Hi-speed with a single transaction translator
`0x02`	Hi-speed with multiple transaction translators