The following page says that Ubuntu 21.04 supports
the latest Intel processor family and its graphics card:
Intel RocketLake及び Intel DG1グラフィックが
サポートされました。
https://kledgeb.blogspot.com/2021/04/ubuntu-2104-20-ubuntu-2104.html
Its kernel version is Linux kernel 5.11.
It means the source code of the above includes
the latest i915-DRM kernel module for Linux.
And if I port it to FreeBSD kernel module, I can used my
TV as full HD display.
This is just for information for the future investigation
on this problem by myself.
As Mozc kana-kanji conversion server does not run well
in this time, I am writing this in English. Before
rebooting FreeBSD today, I could use Mozc well.
The difference between rebooting is installing the
latest FreeBSD 13 stable. After booting FreeBSD today,
I compiled the world with the latest OS source and updated
the whole packages on my PC by pkg upgrade command.
----