HCL:Raspberry Pi3 TPM

This is a guide for setting up a TPM module on a Raspberry Pi 3 or 4. This guide is based on LetsTrust TPM from pi3g.

extraconfig.txt update

You first need to add few information in extraconfig.txt file:

dtparam=spi=on
dtoverlay=tpm-slb9670

Kernel module: tpm_tis_spi

Once booted, you need to load the tpm_tis_spi kernel module. You can do it manually:

sudo modprobe tpm_tis_spi

If you want to load it automatically on boot, you can create /etc/modules-load.d/tpm.conf with the following content:

# Load tpm_tis_spi to use TPM module
tpm_tis_spi

Once the kernel module is loaded, you should get the following traces:

[   27.301273] tpm_tis_spi spi0.1: 2.0 TPM (device-id 0x1B, rev-id 22)
[   27.304167] tpm tpm0: A TPM error (256) occurred attempting the self test
[   27.304197] tpm tpm0: starting up the TPM manually