IMX8Plus IoT Gate

Did someone succesfully run OpenWrt on that Hardware (Compulab IoT Gate IMX8Plus)

Which target image is to use?

/targets/armsr/armv8/
/targets/imx/cortexa7/

figure out which device(s) use the same SoC using https://openwrt.org/toh/views/toh_extended_all

Actuall I have follwing problem:

[    1.296547] Waiting 5 sec before mounting root device...
[    1.320562] mmc2: new HS400 Enhanced strobe MMC card at address 0001
[    1.327434] mmcblk2: mmc2:0001 eMMC   29.1 GiB
[    1.333536] Alternate GPT is invalid, using primary GPT.
[    1.338888]  mmcblk2: p1 p2 p128
[    1.342695] mmcblk2boot0: mmc2:0001 eMMC   4.00 MiB
[    1.348176] mmcblk2boot1: mmc2:0001 eMMC   4.00 MiB
[    1.353456] mmcblk2rpmb: mmc2:0001 eMMC   4.00 MiB, chardev (247:0)

and then the boot proccess stopped

the root device is root=/dev/mmcblk2p2 in the grub.cfg

What could be the reason for that problem?