Platform Info (BIOS INT 1AH Functions)

This table shows the test result of BIOS INT 1AH Functions. In this test, we use "tpm test" command that supported by Grub-IMA patch. Let us know the your test result and please feel free to contact us (mailto: munetoh at if you have any question.

Sorted by BIOS release date

Vendor, Type, P/N BIOS Version BIOS Date BB00h BB01h BB02h BB03h BB04h BB05h BB06h BB07h
TCG_ Status CheckTCG_ Hash Log Extend Event TCG_ Pass Through To TPM TCG_ Shutdown Pre Boot Interface TCG_ Log Event TCG_ Hash All TCG_ TSS TCG_ Compact Hash Log Extend Event
IBM, Thinkpad X30, 26724HJ 1KET46WW (1.07 ) 07/02/2004OK (v1.0)OK (F2 only) OK-OK (w/ extend) OK -NA
Lenovo, Thinkpad X60, 1706Q6J 7BETC7WW (2.18 ) 03/07/2007OK (v1.2)OK (F1,F2) OK-OK (w/o extend) OK -OK
DELL, OptiPlex 755 A01 08/10/2007OK (v1.2)OK (F1,F2) OK - OK (w/o extend) OK - OK
HP, dc7800p, GC760AV 786F1 v01.04 08/27/2007OK (v1.2)(1) OK-(1) OK - (1)
Panasonic W7,CF-W7BWHAJS V1.00L10 09/28/2007OK (v1.2)OK (F1,F2) OK-OK(w/ Extend)OK - OK
Intel,DQ35JO JOQ3510J... 01/02/2008OK (v1.2)NG ? -NG OK-OK

1) Could not check the BIOS since the eventlog was broken.

How to Check?

Let's use KNOPPIX511 Trusted Computing Geeks to check the BIOS Int 1AH capability of your PC.

  1. Enable TPM (BIOS Configuration)
  2. Boot TC Geeks.
  3. at GRUB menu screen, type "c" to enter the console mode
Grub> tpm test
Start BIOS TCG compliance check
0) TCG_StatusCheck - INT 1Ah (AH)=BBh,(AL)=00h
TCG Version major   : 1
TCG Version major   : 2
BIOS Eventtable ptr : 0x3F6E1C26
1) TCG_HashLogExtendEvent - INT 1Ah (AH)=BBh,(AL)=01h (v1.1 & v1.2) (Format 2)
 Good Eventlog & PCR - OK
2) TCG_PassThroughToTPM - INT 1Ah (AH)=BBh,(AL)=02h
3) TCG_ShutdownPreBootInterface - INT 1Ah (AH)=BBh,(AL)=03h
4-1) TCG_LogEvent (w/ Extend) - INT 1Ah (AH)=BBh,(AL)=04h (IBM/Lenovo only?)
 Wrong PCR Value = 0000....
       should be = 0EE2....
 Event Log is OK, but PCR[14] has wrong value
4-2) TCG_LogEvent (w/o Extend) - INT 1Ah (AH)=BBh,(AL)=04h (v1.2)
 Good Eventlog & PCR - OK
5) TCG_HashAll - INT 1Ah (AH)=BBh,(AL)=05h
6) TCG_TSS - INT 1Ah (AH)=BBh,(AL)=06h- TBD
7) TCG_CompactHashLogExtendEvent - INT 1Ah (AH)=BBh,(AL)=07h

Next, try with --format=1 option to check the another input format of BB01h(TCG_HashLogExtendEvent) call.

Grub> tpm test --format=1
1) TCG_HashLogExtendEvent - INT 1Ah (AH)=BBh,(AL)=01h (v1.1 & v1.2) (Format 1)
 Good Eventlog & PCR - OK

Known problems

BB01h (TCG_HashLogExtendEvent)

IBM BIOS with TPM v1.1b support "Format 2" input defined by TCG v1.2 spec.

BB04h (TCG_LogEvent)

There are two behaviors, The call with Extend operation, and without Extend operation. In the TCG v1.2 specification, "without Extend" is right operation.

Broken Eventlog

Some PC destroy the ACPI Eventlog table structure after Int 1Ah BB01h(TCG_HashLogExtendEvent) call.


TCG PC Specific Implementation Specification Version 1.1 (pdf, 403Kb)
TCG PC Client Specific Implementation Specification for Conventional Bios Version 1.2 (pdf, 809Kb)
Windows Vista BitLocker Client Platform Requirements, this requires BB00,BB02,BB03, and BB07