PscgBuildOS: adding a new architecture (s390x) to various distros. Walkthrough and troubleshooting

In this video we add together a new architecture to the build.
The chosen architecture is IBM's Mainframes, aka s390x, and we cover (including errors and honest mistakes!) all steps that are needed to add a new architecture
for:
pscg_busyboxos
pscg_debos

It shows everything including the external static builds, and shows nicely the elegance of the design - it's just easy to get to Embedded Linux concepts by following my teaching. Things are easy - but you need to understand the concepts!

While the porting efforts themselves could have been recorded and edited to take
2 minutes top, the video shows A LOT of concepts and troubleshooting guides, that are expected in any real work.
The documentation for how to add a new device has already been added for the loongarch64 port, and is in project's markdown documentation.
I actually also troubleshooted some things that were not a trouble, but running
the wrong run-qemu script, but I do think it shows some good stuff, and also aligns very well with the storage optimization and constraints videos.

As the video got longer and longer, there is still one more thing to add - input
devices in QEMU - which you can achieve by specifying INPUTPARAMS_0 . E.g.:
INPUTPARAMS_0="-device virtio-mouse-pci -device virtio-keyboard-pci" /home/ron/aug19-pscgbuildos/artifacts/runqemus/pscg_debos-debian-trixie-minbase-s390x/run-qemu.sh

Since the s390 QEMU display only shows 4 colors (or 16?), as can be clearly seen by the kernel logo in the video several times, Weston will refuse to work with this color settings.
There is no point in adding more support for it at this time, so although this particular architecture is not suitable for your porting exercises - it does present a handful of challenges (and problems), for you to learn on other architectures, and have a much easier journey!

Note: Running on real s390x hardware and products would work well, but I don't think I will be able to provide you a BSP.