Bill XIE has posted comments on this change. ( https://review.coreboot.org/19521 )
Change subject: mb/gigabyte/ga-b75m-d3h: Add tpm support for its onboard tpm socket ......................................................................
Patch Set 7:
(1 comment)
https://review.coreboot.org/#/c/19521/5/src/mainboard/gigabyte/ga-b75m-d3h/K... File src/mainboard/gigabyte/ga-b75m-d3h/Kconfig:
Line 21: select MAINBOARD_HAS_LPC_TPM
add select TPM because we have two implementation using the same driver tpm
Below is a SeaBIOS log about TCGBIOS fetched from my Thinkpad x230 after apply Change 19535:
TCGBIOS: Detected a TPM 1.2. TCGBIOS: Starting with TPM_Startup(ST_CLEAR) Return from build_and_send_cmd(99, 0 1) = 26 Return from build_and_send_cmd(4000000a, 0 8) = 0 TCGBIOS: Return code from TPM_GetCapability(5, 277) = 0 TCGBIOS: Return code from TPM_GetCapability(5, 288) = 0 TCGBIOS: timeouts: 750000 750000 750000 750000 TCGBIOS: durations: 6000000 6000000 180000000 Return from build_and_send_cmd(50, 0 0) = 0 WARNING - Timeout at tis_wait_sts:160! Return from build_and_send_cmd(4000000b, 0 0) = ffffffff TCGBIOS: TPM malfunctioning (line 864). WARNING - Timeout at tis_wait_sts:160!
There will be no 't' menu item within SeaBIOS' menu, and then TPM becomes deactivated in the OS. If there is no SeaBIOS in the bootloader payload chain, TPM would not get deactivated, but it seems SeaBIOS is needed to revived a cleared TPM. Note that on sandybridge platforms like t420 and x220, SeaBIOS works fine.