On Sun, 4 Aug 2019 at 19:12, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > > Hi, > > On 04-08-19 17:33, Ard Biesheuvel wrote: > > Hi Hans, > > > > On Sun, 4 Aug 2019 at 13:00, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > >> > >> Hi All, > >> > >> While testing 5.3-rc2 on an Irbis TW90 Intel Cherry Trail based > >> tablet I noticed that it does not boot on this device. > >> > >> A git bisect points to commit 166a2809d65b ("tpm: Don't duplicate > >> events from the final event log in the TCG2 log") > >> > >> And I can confirm that reverting just that single commit makes > >> the TW90 boot again. > >> > >> This machine uses AptIO firmware with base component versions > >> of: UEFI 2.4 PI 1.3. I've tried to reproduce the problem on > >> a Teclast X80 Pro which is also CHT based and also uses AptIO > >> firmware with the same base components. But it does not reproduce > >> there. Neither does the problem reproduce on a CHT tablet using > >> InsideH20 based firmware. > >> > >> Note that these devices have a software/firmware TPM-2.0 > >> implementation, they do not have an actual TPM chip. > >> > >> Comparing TPM firmware setting between the 2 AptIO based > >> tablets the settings are identical, but the troublesome > >> TW90 does have some more setting then the X80, it has > >> the following settings which are not shown on the X80: > >> > >> Active PCR banks: SHA-1 (read only) > >> Available PCR banks: SHA-1,SHA256 (read only) > >> TPM2.0 UEFI SPEC version: TCG_2 (other possible setting: TCG_1_2 > >> Physical Presence SPEC ver: 1.2 (other possible setting: 1.3) > >> > >> I have the feeling that at least the first 2 indicate that > >> the previous win10 installation has actually used the > >> TPM, where as on the X80 the TPM is uninitialized. > >> Note this is just a hunch I could be completely wrong. > >> > >> I would be happy to run any commands to try and debug this > >> or to build a kernel with some patches to gather more info. > >> > >> Note any kernel patches to printk some debug stuff need > >> to be based on 5.3 with 166a2809d65b reverted, without that > >> reverted the device will not boot, and thus I cannot collect > >> logs without it reverted. > >> > > > > Are you booting a 64-bit kernel on 32-bit firmware? > > Yes you are right, I must say that this is somewhat surprising > most Cherry Trail devices do use 64 bit firmware (where as Bay Trail > typically uses 32 bit). But I just checked efibootmgr output and it > says it is booting: \EFI\FEDORA\SHIMIA32.EFI so yeah 32 bit firmware. > > Recent Fedora releases take care of this so seamlessly I did not > even realize... > OK, so we'll have to find out how this patch affects 64-bit code running on 32-bit firmware. The only EFI call in that patch is get_config_table(), which is not actually a EFI boot service call but a EFI stub helper that parses the config table array in the EFI system table.