imx8mp evk - boot stucks at BL31

[Elmar Psilog]

I am on a imx8.mp evk board. I could build and start loader (SPL, UBOOT,
DT, ATF/BL31, mkimage) from the freescale git. Due to some problems I
switched to mainland Uboot 2021-1. I found SPL/ATF is booting, but it
stops with:

NOTICE: BL31: ....

If I replace in imx-mkimage just the file u-boot-nodtb.bin with NXP's
uboot, than it boots (it shows the U-Boot-2020.04 banner). So something
went wrong with 2021-1 uboot or its default config. What can this be? I
enabled log level 7, but nothing to be seen.

(BTW: When enables loglevel >6 for SPL, SPL fails in DDR training. In
NXP 20.04 SPL I couldn't compile with SPL log support)