booting by "kexec -l grub.exe", "kexec -e" from Linux gets stuck in Macbook Air 2013

[yanjiew1]

I try to boot grub.exe from Linux. However, it is stuck at command line. The keyboard is not functional.

The kernel version I used is 4.9.13 from buildroot. the grub4dos version is 2017-08-30 0.4.6a.