Cannot boot debian kernel after flash linux

hello, everyone
I bought a hikey960 board and wanted to install debian linux on it. I installed according to Linux Host Installation for HiKey960 - 96Boards,but after reboot, it stopped at “Press ESCAPE for boot options .Android fastboot mod -version 0.7. Press RETURN or SPACE key to quit.” when i get into UEFI menu, I found it cant choose grub, always back to EFI menu
please help me, I have been struggling with this issue for days…
the console showns as follows: