Lenovo OEM Data (Type 140)

Source: dmidecode, dmioem.c, the README files of the firmware updates of Lenovo, and the dumps of the data corpus.

Holds one OEM structure of a Lenovo system, told by its number and revision. OEM structures 0 to 9 are found in the data corpus, and only structure 7, the embedded controller program, is decoded. Structure 9 refers to two strings too, which hold the same version, e.g. 1.32, whose meaning is not established; ThinkPad E14 Gen 5 carries the first of them only, so that the second reference is left dangling.

Table 1. Lenovo OEM Data structure
Offset	Version	Name	Length	Value	Description
`0x00`	2.0+	Type	`BYTE`	`140`	Lenovo OEM Data indicator
`0x01`	2.0+	Length	`BYTE`	Varies	Length of the structure
`0x02`	2.0+	Handle	`WORD`	Varies
`0x04`	2.0+	Signature	6 BYTEs	`LENOVO`
`0x0A`	2.0+	OEM Structure Offset	`BYTE`	`0x0B`	Offset of the OEM structure number
`0x0B`	2.0+	OEM Structure Number	`BYTE`	`NUMBER`
`0x0C`	2.0+	OEM Structure Revision	`BYTE`	`NUMBER`
`0x0D`	2.0+	Data	Varies	Varies	Data of the OEM structure, see below

Table 2. ThinkPad embedded controller program (OEM structure 7, revision 1)
Offset	Name	Length	Description
`0x0D`	Version ID	`STRING`	Version of the program, which the README files of the firmware updates of Lenovo name, e.g. `N20HT28W`
`0x0E`	Release Date	`STRING`	Release date of the program, e.g. `10/08/2020`