Issue Booting on NanoPC-T4

[Travis Whitton]

Hello, I'm running into problems trying to get the official upstream
nanopc-t4-rk3399_defconfig to work on my NanoPC-T4. I'm building u-boot on
Ubuntu/Focal (docker container) as follows:

# cd /root
# apt-get update
# apt-get install build-essential flex bison gcc-aarch64-linux-gnu git
device-tree-compiler python3 gcc-arm-none-eabi bc
# git clone https://github.com/ARM-software/arm-trusted-firmware.git
# cd arm-trusted-firmware
# make realclean
# make CROSS_COMPILE=aarch64-linux-gnu- PLAT=rk3399
# export BL31=/root/arm-trusted-firmware/build/rk3399/release/bl31/bl31.elf
cd /root
# git clone https://github.com/u-boot/u-boot.git
# cd u-boot
# make CROSS_COMPILE=aarch64-linux-gnu- nanopc-t4-rk3399_defconfig
# make CROSS_COMPILE=aarch64-linux-gnu-

After the successful build, I copied idbloader.img and u-boot.itb to my
NanoPC-T4 and attempted to install them like so:

# dd if=idbloader.img of=/dev/mmcblk2 conv=fsync,notrunc bs=512 seek=64
# dd if=u-boot.itb of=/dev/mmcblk2 conv=fsync,notrunc bs=512 seek=16384

After installing, the boot process never makes it to a login prompt. In
order to get the dmesg output, I connected to the machine via UART, and I
captured the following logs:

https://gist.github.com/tmountain/f3fd939dece80aaeb069c28db7d54e3d

Please advise if I'm doing something wrong. I am available to assist with
testing if necessary.

Thanks,
Travis