Can I upgrade my Elitebook 840 G2 TPM firmware to 2.0 and use it under Linux?

[enok71]

I have read that my Elitebook 840 G2 has a Infineon SLB9660 TPM chip. According to Infineon this chip can be upgraded from TPM 1.2 to TPM 2.0. Under Linux there is an open source software https://github.com/iavael/infineon-firmware-updater which can be used. I have found firmware images for doing the upgrade.

But from other answers here on HP support it is not possible to upgrade the Elitebook 840 G2 to TPM 2.0. So I hesitate trying this in order to avoid bricking my laptop (or making the TPM unusable). Especially as I haven't found any firmware image binaries for downgrading back to 1.2 in case of problems.

So please help me: what happens if I try this TPM firmware upgrade to 2.0 under Linux? Will I still be able to use secure boot, or will the BIOS perhaps be unable to use the TPM 2.0, assuming the TPM firmware upgrade succeeds? 

[tk_srq]

@enok71,

According to this HP link about TPM update, your Infineon SLB9660 chip is most likely too old to be upgraded to TPM2.0. 

HPSBHF03568 rev. 11 - Infineon TPM Security Update | HP® Customer Support

HP provides only higher version of TPM1.2 via sp82133. The screenshot below is from the manual from sp 82133.

 If you try the Github method and fail, there seems to be no way to restore TPM1.2 back, as HP doesn't provide your original TPM1.2 bin file and the restoration procedure. In the worst case, it may corrupt the BIOS, too, as TPM and BIOS work hand by hand.

[enok71]

According to the Infineon (chip manufacturer) website all SLB 9660 chips are shipped with TPM 1.2 but "firmware upgradeable to TPM 2.0". So the chip is most likely not to old.

But I agree it could be that the HP BIOS on the Elitebook 840 G2 perhaps wouldn't work with a TPM 2.0 firmware. Or perhaps it would work ...  seems that Elitebook 840 G3 has the SLB 9665 TPM chip which (it seems) is exactly a SLB 9660 with TPM 2.0 firmware.

So: no clear conclusion.

[tk_srq]

@enok71,

Ok, I see the SLB9660 is actually upgradable to TPM2.0. But the fact is that HP had only higher version of TPM1.2 firmware available thus created and released the sp82133 package in 2018. Perhaps, Infineon released the TPM2.0 data later on.

The Github method may update your chip to TPM2.0 under Linux but Whether HP BIOS recognizes it or not is another thing. If you try it successfully and report it back here, you'll be the first documented person for this great achievement.🙂