[systemd-devel] Issues supporting systems with and without TPM and firmware TPM (was Re: Handle device node timeout?)

[Lennart Poettering]

On Mo, 15.04.24 10:38, Mikko Rapeli (mikko.rapeli at linaro.org) wrote:

> Hi,
>
> On Fri, Apr 12, 2024 at 05:03:18PM +0300, Aleksandar Kostadinov wrote:
> > Shouldn't the kernel automatically load the necessary modues when
> > devices are detected... given proper udev rules and module
> > availability in the initrd filesystem? I guess it depends on how you
> > build your initrd system for including them.
>
> The modules do get loaded but too late in the initramfs stage and something
> in the tpm2.target and related service was failing and creating TPM2 encrypted
> rootfs fails. I could not figure out at which stage the driver needs to be loaded,
> e.g.
> Before: modprobe at tpm_tis_core.service modprobe at tpm_tis.service modprobe at tpm_ftpm_tee.service
>
> But I'm also trying to fix the root causes why TPM modules can't be built into the
> kernel so lucky that resolves these issues. Would be nice to know to which stage
> the TPM2 module loading would need to happen though.

This should not require manual handling. The driver should be
auto-loaded via udev and stuff, like any other driver. Or does the
"tpm-ftpm_tee" thing carry no modalias info that autoloads it if some
specific hw is around?

Lennart

--
Lennart Poettering, Berlin