PlatformBiosInt1AhInfo - Open Platform Trust Services Wiki - Open Platform Trust Services

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 users.sourceforge.jp) 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 Check	TCG_ 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 )	07/02/2004	OK (v1.0)	OK (F2 only)	OK	-	OK (w/ extend)	OK	-	NA
Lenovo, Thinkpad X60, 1706Q6J	7BETC7WW (2.18 )	03/07/2007	OK (v1.2)	OK (F1,F2)	OK	-	OK (w/o extend)	OK	-	OK
DELL, OptiPlex 755	A01	08/10/2007	OK (v1.2)	OK (F1,F2)	OK	-	OK (w/o extend)	OK	-	OK
HP, dc7800p, GC760AV	786F1 v01.04	08/27/2007	OK (v1.2)	(1)	OK	-	(1)	OK	-	(1)
Panasonic W7,CF-W7BWHAJS	V1.00L10	09/28/2007	OK (v1.2)	OK (F1,F2)	OK	-	OK(w/ Extend)	OK	-	OK
Intel,DQ35JO	JOQ3510J...	01/02/2008	OK (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
 OK
   PCR[15]=9E70.....8AEB
3) TCG_ShutdownPreBootInterface - INT 1Ah (AH)=BBh,(AL)=03h
 SKIP
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
 OK!
6) TCG_TSS - INT 1Ah (AH)=BBh,(AL)=06h- TBD
 SKIP
7) TCG_CompactHashLogExtendEvent - INT 1Ah (AH)=BBh,(AL)=07h
 OK!

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

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

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.

References

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