On 6/11/20 8:36 AM, Jason Andryuk wrote:
SeaBIOS commit 67643955c746 (make SeaBios compatible with Xen vTPM.) made tpm_start() exit before calling tpm_startup(). The commit message has no explanation why this change was made. Does anyone remember why it was made?
The code today means SeaBIOS will not populate PCRs when running on Xen. If I revert the patch, SeaBIOS populates PCRs as one would expect. This is with a QEMU-emulated TPM backed by swtpm in TPM 1.2 mode (qemu & swtpm running in a linux stubdom).
Any insight is appreciated.
My guess would be that for some reason the TPM 1.2 was already started up through other means and didn't need the SeaBIOS tpm_startup() to run.