rpi cm4 + waveshare mini base board B seems stop after kernel load

[MOCHIDA Shuji <mochid%netside.co.jp@localhost>]

Hi,

 I got Raspberry pi compute module 4(4MB, no eMMC) and
Waveshare's Mini Base Board(B).

  CM4
    https://www.raspberrypi.org/products/compute-module-4/

  Waveshare CM4-IO-BASE-B
    https://www.waveshare.com/product/raspberry-pi/boards-kits/compute-module-4-cat/cm4-io-base-b.htm

dd'ed 2021-06-20-netbsd-raspi-aarch64.img to uSD and power-on,

    http://cdn.netbsd.org/pub/NetBSD/misc/jun/raspberry-pi/2021-06-20-aarch64/2021-06-20-netbsd-raspi-aarch64.img.gz

EFI firmware loaded and boot loader prints sizes, but seems stop there,
no UBC copyright shown.

serial line pluged to GPIO 14(pin8,TxD), 15(pin10,RxD). log here

    http://www.netside.co.jp/~mochid/comp/rpi/nb-jun-aarch64-log.txt

2021-05-07-raspios-buster-arm64-lite.img boot log below:
(I added "enable_uart=1" to config.txt)

    http://www.netside.co.jp/~mochid/comp/rpi/raspios-cm4-boot.txt
    http://www.netside.co.jp/~mochid/comp/rpi/raspios-cm4-lsR-sys-fw-dt.txt
    http://www.netside.co.jp/~mochid/comp/rpi/raspios-cm4-dmesg-out.txt

Any Hints? Something should I try next?

-mochid