Succeeded to boot on Lenovo Yoga C630

Hello,

I cannot find the original mail in my mailbox, but it is continued
from this mail.
https://freebsd-arm.freebsd.narkive.com/dBBAi0yX/loader-efi-does-not-boot-on-lenovo-yoga-c630

FreeBSD's bootaa64.efi that is distributed officially does not boot on
Lenovo Yoga C630.
OpenBSD 7.2's bootaa64.efi booted fine on Yoga C630, so I merged
OpenBSD's start.S and ldscript.arm64.
boot1.efi booted fine, but loader_lua.efi still needed to be tweaked.

It seems that probing on serial console freezes the loader.
Commenting out serialconsole made the loader_lua.efi to boot the kernel.
And then, the kernel stopped and complained that it cannot find the
device tree blob.

So my questions are:
1. Can I disable loader from probing comconsole by some configuration?
(without tweaking the source.)
2. How should I make the loader or kernel to find the dtb file?

Thank you.

Hiroo Ono