> I am trying to get my new pi to boot, I have replaced the bootcode.bin with
> the one from raspbian buster, unfortunately the pi stalls.
>
> Any suggestions what else to try??

A quick search engine use lead to
https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/
stating:
"Note: The Raspberry Pi 4B does not use the bootcode.bin file - instead
the bootloader is located in an on-board EEPROM chip. The Pi 4B
bootloader currently only supports booting from an SD card."

That's all I could find in 1 min 37 s. I own no Raspberry myself.
Bernard Rosset
https://rosset.net/