Intel Firmware Version Information (Type 221)

Source: reverse engineered from the dumps of the data corpus, and consistent with the firmware version information of the Intel reference code.

Lists the versions of the firmware components of a platform, as the Intel reference code knows them: the reference code modules, the microcode, the Management Engine firmware, the option ROMs and others. Each module of the reference code, e.g. the CPU, the Management Engine, the PCH or the System Agent, adds a structure of its own, whose first item is the version of the module itself, named Reference Code - <module>. A group association (type 14) named Firmware Version Info often lists the structures of the platform.

The structures are found on Intel platforms whatever the vendor of the firmware is. The reference code gives them type 221 by default, which some vendors give to structures of their own: Dell places the structures at type 205 or 237, or keeps them at type 221 on some systems, e.g. XPS 13 9350, where its own structures of that type are told apart by their length of 19 bytes and by carrying no strings, while HP servers carry none.

Table 1. Intel Firmware Version Information structure
Offset	Version	Name	Length	Value	Description
`0x00`	2.0+	Type	`BYTE`	`221`	Intel Firmware Version Information indicator, `205` on Dell platforms
`0x01`	2.0+	Length	`BYTE`	Varies	Length of the structure, `0x05` + 7 × Item Count
`0x02`	2.0+	Handle	`WORD`	Varies
`0x04`	2.0+	Item Count	`BYTE`	`NUMBER`	Number of items
`0x05`	2.0+	Items	Varies	Varies	Versions of the firmware components, see Items

1. Intel Firmware Version Information — Items

Each part of the version is unspecified on its own, with all bits set. Components which carry a single number set that part only, e.g. the revision identifiers of the PCH and the System Agent set the build number, and the HSIO versions set the major version. Components which carry a state rather than a version, e.g. PCH-CRID Status, give it as the version string.

The parts are written in decimal or in hexadecimal depending on the component: the versions of the Management Engine firmware in decimal, e.g. 16.1.32.2473, and the versions of the reference code modules in hexadecimal, e.g. 7.0.5C.50.

The revision of the microcode, uCode Version, is the revision followed by the low byte of the build number, (revision << 8) | build: e.g. revision 4 and build 55 stand for 0x437 of Alder Lake-P, and revision 0x41 and build 14 for 0x410E of Raptor Lake-P. The older platforms give it in the build number alone, e.g. build 234 for 0xEA.

Some items whose other parts are all unspecified give the build number as 0x00FF rather than 0xFFFF, e.g. UNDI Version and MEBx version on some platforms, which is presumably a byte of all bits set.

Table 2. Intel Firmware Version Information: Item
Offset	Name	Length	Value	Description
`0x00`	Component Name	`BYTE`	`STRING`	Name of the component, e.g. `Reference Code - CPU` or `ME Firmware Version`
`0x01`	Version String	`BYTE`	`STRING`	Version written as a string, or state of the component, e.g. `Consumer SKU` or `Disabled`
`0x02`	Major Version	`BYTE`	`NUMBER`	`0xFF` if unspecified
`0x03`	Minor Version	`BYTE`	`NUMBER`	`0xFF` if unspecified
`0x04`	Revision	`BYTE`	`NUMBER`	`0xFF` if unspecified
`0x05`	Build Number	`WORD`	`NUMBER`	`0xFFFF` if unspecified