On Sat, 12 Jul 2025 at 18:25, Jonas Kvinge <jona...@opensuse.org> wrote: > > Hi, > > I'm working on getting Raspberry Pi CM5 with a source kit io board and > LetsTrust TPM with u-boot and Linux working. > I'm building a custom u-boot similar to the description > here: > https://github.com/joholl/rpi4-uboot-tpm/blob/ad31306ce2f2d52f0572385bfc8bac33cb1f1f68/README.md#setting-up-and-configuring > > I've got this successfully working on the CM4 where the PCR's are > extended on boot. > > I'm now trying a similar setup on the CM5. > I use openSUSE Tumbleweed with a custom built u-boot and linux kernel. > I use kernel 6.12.35 with all the Raspberry Pi modifications > from https://github.com/raspberrypi/linux > > The TPM is detected, but the PCR's are not extended, showing zeros for > all PCRs (tpm2_pcrread).
The TPM is detected where? In the kernel? If its' not detected in U-Boot it won't be able to extend the PCRs throughout the boot process so that's about what I would expect. > In addition to the tpm-slb9670.dtbo from the latest firmware files for > the Raspberry Pi > (https://raw.githubusercontent.com/raspberrypi/linux/refs/heads/rpi-6.12.y/arch/arm/boot/dts/overlays/tpm-slb9670-overlay.dts > ), I use the tpm-soft-spi.dts > from > https://raw.githubusercontent.com/joholl/rpi4-uboot-tpm/ad31306ce2f2d52f0572385bfc8bac33cb1f1f68/Raspberry_Pi_OS_64bit/tpm-soft-spi.dts What does that overlay do? > Do these needs to be modified for Raspberry Pi Compute Module 5, or > could it be something in u-boot that needs to be changed? Well does the TPM2 work in U-Boot? I suspect the SPI 40 pin connector is via the RP1 chip, although I'm not sure, we don't yet support the RP1 in U-Boot, let alone it's various peripherals. But maybe the SPI is from the SoC. Looking into that would be where I would start your investigations. Peter
