Hikey970 fails to boot

Board based on the Kirin 970 - HI3670 Application Processor

I followed the steps below to generate a boot image:

  1. make -j4 Image dtbs
  2. cat arch/arm64/boot/Image arch/arm64/boot/dts/hisilicon/kirin970-hikey970.dtb > Image-dtb
  3. mkbootimg --kernel Image-dtb --cmdline “earlycon=pl011,0xfff32e earlycon=pl011,0xfff32000 console=ttyS0,115200n8 console=tty0 console=ttyAMA0,115200 console=ttyAMA3,115200 root=/dev/ram0” --base 0x0 --tags_offset 0x07A00000 --kernel_offset 0x00080000 --output boot.img

Initramfs is built into the kernel.

But the board fails to boot up and is stuck after:
EFI stub: Booting Linux Kernel…
EFI stub: EFI_RNG_PROTOCOL unavailable, no randomness supplied
EFI stub: Using DTB from configuration table
Failed to handle fs_proto
EFI stub: ERROR: Failed initrd from command line!
EFI stub: Exiting boot services and installing virtual address map…

Does anybody know what might be happening?