Creating a custom system image

[arwie]

Hi Kunbus developers,
I just found your revolutionary product and before I order the first unit I have some questions.

I have a custom PTXdist-based system image for x86-Atom-IPC which I would like to port to RevPi. I have already experience in building images for the original RaspberryPi.
What is necessary to build a custom image for RevPi (compared to RaspPi)?

* Is the Preempt-RT patch really necessary? (I want to use an IO and a PROFIBUS gate module, but I have no realtime requirements from the application)
* Does piControl also include a userspace application or is it just a kernel module?
* Can the original RaspPi kernel be used or do you have custom patches in the kernel?
* Where can I download your kernel (if the standard RaspPi kernel kannot be used?)
* Can other users than md compile piControl? (KDIR := /home/md/pi/linux4.1)

I don't need any of the preinstalled software for RevPi (except piControl to access IO and the gate).

A tutorial for experienced linux developers would be great.

Thank you in advance!
I'm looking forward to use RevPi for my application.

Dipl. Ing. Artur Wiebe
Software-Ingenieur
Email: artur@4wiebe.de
Telefon: +491632699840
Web: artur.4wiebe.de
Quellenstraße 49, 72124 Pliezhausen
USt-IdNr: DE299286057

[volker]

Hi Artur,
good to have some people prefering English conversation on our platform.
First of all the system is absolutely open. That means any image that runs on a Raspi Compute Module will run on our hw. BUT: The Compute Module needs a slightly different device tree compared to the "normal" Raspi B+. I can't tell you details now because I'm not deep enough in this stuff. But I will ask my colleagues who are working on the image to answer your questions in detail.
The RT patch is needed to get a stable and reliable cycle time for PiControl. Without the RT patch any kind of Interface traffic (e.g. Ethernet, USB) might cause a huge jitter in the PiControl cycle time. If this is of no importance to you, you might well use the system without it. But using any application like logi.RTS will absolutely need this RT patch as e.g. the watchdog logic would trigger in case of a large jitter. We also do have a watchdog inside RevPi DIO which does need cyclical PiBridge traffic in order not to trigger. Right now (without having a deep look into the source code) I can't really tell you if this could be a knock out for not using RT patch.
We already have put several files on GitHub but I need to talk to our sw team fi the kernel is already uploaded and if not when this will be done. This also is the case for PiControl sources. As soon as these are uploaded you should be be able to compile them yourself. At least we have no plans for any restrictions but do want to enable any cutomers to change whatever they need to.
Please understand that if you will go this way (changing the driver sources) you might cut off yourself from any further changes or bug fixes as well as from any further third party sw which uses our standard access to process image. This is also the case for other parts of the image. E.g. there will be a TeamViewer access to RevPi Core soon but this (and several other sw components) will use pre-installed drivers and agents.

Artur, I fear that you will have to wait quite a long time for such an expert tutorial as there are very view people out there (right now) which could use it. BUT let's try if the forum and the combined expertise can help you getting your specific system running. The KUNBUS team will try to help too so why don't give it a try?

Hopefully our sw experts might give you more answers on Monday...