T1042 - No U-Boot output with Secure Boot

[bradley_gamble]

Hello,

I am currently trying to enable Secure Boot on our device based on the T1042 SOC. I have previously enabled Secure Boot successfully on this device using SDK 1.7's U-Boot and CST. The resulting binary executes successfully on the T1042 device with SB_EN=1 and ITS=1.

I am attempting to update to the latest version of U-Boot (2020.01, upstream). I have built a binary based on the T1042RDB_PI_NAND config and this executes successfully in insecure mode (u-boot-with-spl-pbl.bin) on my device. However, I have then attempted to build U-Boot but with Secure Boot enabled (ie the T1042RDB_PI_NAND_SECURE_BOOT config) and this does not show any output on the serial console with SB_EN=1 set.

Is it expected that upstream U-Boot should function correctly on the T1042 with Secure Boot enabled? I am using the same CST signing process that I have used for the SDK 1.7's binary. Other posts imply that this may not be compatible - Which version of CST should I be using for upstream U-Boot?

[bpe]

We do not verify every release of u-Boot and Linux kernel on our processors. For this reason, we can provide a very limited support to the mainstream versions of them. We do perform commits to the mainstream kernel and u-Boot, so basic features should work, but if you wish to stay with the most recent u-Boot/kernel verified by NXP, use NXP (L)SDK. T1042 target is supported by NXP Yocto-based SDK. The most recent release is built around kernels LTS 5.4.3 and LTS 4.19 and u-Boot v2019.10. The SDK does provide  all necessary tools including CST and predefined u-Boot/PBL/RCW configurations for Secure boot.  See the SDK documentation on how to install and use it.

Best Regards,
Platon