I have installed a CM4 with 2GB, 32GB flash with BT and WIFI with flashed Venus OS on CM4-IO-WIRELESS-BASE-B CM4.
All good for some last steps on the serial ports…
Venus OS Large installed v3.41
To enable USB i had to do additional configuration
waveshare CM4-IO-WIRELESS-BASE-B follow the instructions over there but to enable usb a had to: wget https://github.com/raspberrypi/firmware/raw/master/boot/overlays/dwc2.dtbo to install in /u-boot/overlays/ to make USB device appear on terminal.
At this moment I need some help in enabling the 
RS485 as per instructions from waveshare:
RS485
The default is off, if you want to turn it on, you need to add the following to config.txt:
sudo nano /boot/config.txt dtoverlay=uart3 dtoverlay=uart5
The device numbers are:
/dev/ttyAMA1 /dev/ttyAMA2
de devices do not show up as suggested (ttyAMA1 and 2). when searching I found:
on the victorn community → can-i-use-the-rs485-of-the-waveshare-canrs485-hat
to edit /etc/udev/rules.d/gpio.rules
or
akkudoktor → enus-os-waveshare-rs-485-can-hat-b-zum-laufen-bekommen-rs485/
/etc/udev/rules.d/serial-starter.rules needs some rules.
any support on how to enable RS485 would be appreciated. At this moment I don’t understand the configuration of the serial ports.