PROCESSOR-SDK-AM64X: tiboot3.bin with combined SBL and SYSFW

Dominic Rath

Dear TI team,

we're currently looking into booting the AM64x (U-Boot+Linux) completely out of eMMC.

While working on this, I noticed that the U-Boot binaries that come with the processor SDK Linux RT 08.00.00.21 apparently include the SYSFW inside tiboot3.bin. This is also mentioned briefly in the documentation: https://software-dl.ti.com/processor-sdk-linux/esd/docs/08_00_00_21/linux/Foundational_Components/U-Boot/UG-Memory.html#updating-an-sd-card-from-a-host-pc

We're working on custome hardware, so the prebuilt binaries are obviously no use to us.

I believe this combined image relies on the "Extended Boot Info Extension" to the K3 X509 certificates. This extension is documented in the J7200 TRM, but it is missing from the AM64x TRM. The tiboot.bin that comes with the AM64x linux SDK contains this extension, so I'm pretty sure the AM64x supports this, too. Maybe the TRM could be updated to reflect this?

Unfortunately I've been unable to locate sources that would allow me to re-create this combined tiboot3.bin image.

The U-Boot build process for the various K3 systems that I've seen so far build the tiboot3.bin using tools/k3_gen_x509_cert.sh, but the version in the latest branches on git.ti.com doesn't seem to support this extended boot info extension.

Could you tell me how a tiboot3.bin that integrates u-boot SPL R5 and SYSFW can be generated for the AM64x?

Regards,

Dominic

over 3 years ago

0 Dominic Rath over 3 years ago

Mastermind 7470 points

Ok, I guess I just found the necessary script, or at least a script that knows about the extended boot info extension.

There's a scripts/gen_x509_combined_cert.sh in the k3-image-gen repository.

Some guidance on how to use that with U-Boot would still be welcome.

+1 Bin Liu over 3 years ago in reply to Dominic Rath

TI__Guru**** 168631 points

Hi Dominic,

The Processor SDK doc linked below explains how to build U-Boot combining sysfw to tiboot3.bin (using k3-image-gen).

https://software-dl.ti.com/processor-sdk-linux/esd/docs/08_00_00_21/linux/Foundational_Components/U-Boot/UG-General-Info.html

However, the instruction does miss a step (the second step below) to copy over the prebuilt sysfw binary to k3-image-gen folder. Otherwise the sysfw binary is downloaded from linux-firmware project.

cd <path to k3-image-gen project>
ln ../prebuilt-images/ti-sci-firmware-am64x-gp.bin .
make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabihf- SOC=am64x SBL=<output directory>/r5/spl/u-boot-spl.bin

0 Dominic Rath over 3 years ago in reply to Bin Liu

Mastermind 7470 points

Hello Bin,

thanks a lot, I missed that step in the documentation, since building the R5f U-Boot SPL already generated a tiboot3.bin, but of course that one was missing the SYSFW.

Regards,

Dominic

0 Bin Liu over 3 years ago in reply to Dominic Rath

TI__Guru**** 168631 points

Hi Dominic,

Thanks for the update.

I do agree the documentation is not very clear. This k3-image-gen step should be in the R5/tiboot3.bin build section. I will track it to update the documentation in future releases.

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PROCESSOR-SDK-AM64X: tiboot3.bin with combined SBL and SYSFW