Long story short, I used to use Ubuntu 16.04 PPC in QEMU for development purposes, but it's woefully outdated, so I thought about installing Debian instead.
First I attempted to replicate what Action Retro did with Debian 11 using qemu, but none of the apt mirrors worked during installetion. Then I looked at these guides for Debian 10:
https://forum.powerprogress.org/d/1-debian-10-0-unofficial-iso-with-post-installation-script-and-pkg-updates
https://forum.powerprogress.org/d/15-debian-10-updated-installation-images-for-debian-ports-2019-11-22
https://wiki.powerprogress.org/OpenStackPPC64Debian10
Unfortunately I still couldn't set up a working desktop. Could someone write a step-by-step qemu guide for dummies on how to do this? I'm pretty sure I messed everything up, including the partitioning.