Raspberry Pi support?

[truher]

hi WPILib folk,

since the SystemCore device is based on a CM5, I'm wondering if the WPIlib suite, including DS communication and actuator heartbeat, will be able to run on a raspberry pi? for training scenarios in the lab, we don't need everything the SystemCore offers, in fact we really only need an RPi with a CAN hat. Would that work?

[Spenceroni-Pepperoni]

I just wanted to bump this. I am currently a mentor on FRC888 and this is something we're looking into. Is there a way in the Beta9/10 version to get it running on a raspberry pi 4B/5? For the same reason as the poster above

[ThadHouse]

This is not something that is easily possible to support. The setup depends on all the hardware being there and it’s not easily possible to shim portions out. This isn’t something we’re able to support.

[qwertychouskie]

I wouldn't ever expect official support, but running on an RPi 5 should technically be possible, if you mess around enough with stubbing/emulating various bits that the OS expects to be present.

At a minimum, you'll need to have vcan virtual CAN interfaces to stub out any interfaces not provided by your CAN hat. (For example, if your hat provides can_s0 and can_s1, you'd need to use vcan for can_s2 through can_s4.)

My understanding was that older OS images mostly just needed the CAN stubbing, but I wouldn't be surprised if newer images need a good bit more tinkering to get working. (If you do end up getting it working, consider posting about it so other can replicate it :)

(And RPi 4 and below are not practically possible, as the SystemCore OS is compiled to use newer Arm instruction set extensions not found in the older CPUs of the RPi 4 and below. While you can technically work around this issue for individual binaries using a kernel module that essentially emulates these instructions, doing so for the entire OS sounds like pain even I don't want to embark on...)

[EnDeRWiGiN]

Would be awesome if i was able to use something like this. https://mjbots.com/products/mjbots-pi3hat-r4-5

[Spenceroni-Pepperoni]

I had a few of my students get it working so I'll have them post to this thread and also on Chief.

[avacado-a]

Hi! I'm a team member from the 888 Robotiators working on this. We managed to get an early version of SystemCoreOS running successfully on a RPI5 by flashing the OS onto the SD card and manually fixing the boot configuration. (We originally attempted this on a RPI4, but it failed to boot properly. We don't know why but we think it is because of the aforementioned ARM instruction set mismatches or the new RP1 chip on the RPI5)

To get the Pi 5 to boot, we had to edit the config.txt file on the flashed micro SD card's boot partition.

By default, the file looks something like this:

cmdline=cmdline_b.txt

start_file=start4.elf

You just have to add [all]:

cmdline=cmdline_b.txt
[all]
start_file=start4.elf

It seems this is necessary because of how the OS boot conditions are formatted. All of the specialized configuration for the OS (i.e., kernel=Image, hardware overlays, and CAN bus setups) were under a [boot_partition=3] filter. Because the RPI5 defaulted to partition 1 or 2, it ignored the custom kernel.

From there, we just connected it to another computer via Ethernet to access http://robot.local.
( If you want to access the OS terminal, you can connect a USB keyboard, use Alt+F2 to clear and it will prompt a login, systemcore is both the username and password. )

We haven't tried a CAN hat with the RPI5 yet or a newer SystemCoreOS.

[Alone1206]

I used an off the shelf 2 ch MCP2518FD HAT, and my RPi 5 running the stock SC image was able to see it after some vcan configuration. I was able to reconfigure and see the CTRE devices on the bus, but I wasn’t able to run any of them. DS would enable but won't run the krakens because the other 3 busses were missing. This was last August, so many things might have changed since then.