Issue with latest update on RPI4

zaphod24

I've been running 4.8 for some time on my RPI 4 and yesterday decided to update from 4.8.1 to 4.8.4 including OS updates. It seems the latest OS update changes the kernel on RPI4 from armv7l to aarch64.

After the update, my 8bitDo SN30pro gamepads weren't working in the emulators, or at least the start and select buttons were not. Usually when that happens I will uninstall xpad and rebuild it from source and that solves the problem.

Unfortunately I was not able to build from source as there doesn't appear to be any kernel heavers for the armv8 kernel (lots of people running raspbian complain about it).

My workaround for now is changing the config.txt and adding arm_64bit=0 so that it still boots the old armv7l kernel. Doing that has everything working correctly on 4.8.4.

Any thoughts to correcting the issue with the 64bit kernel, or should I stick to 32bit for now?

mitu

@zaphod24 said in Issue with latest update on RPI4:

It seems the latest OS update changes the kernel on RPI4 from armv7l to aarch64.

This only happens when you either:

have the system using the bullseye based RaspiOS, still un-supported by RetroPie
used raspi-update to get the latest kernel and firmware - not recommended unless you want to test out a specific fix/feature. raspi-update should not be used as an update method.

Unfortunately I was not able to build from source as there doesn't appear to be any kernel heavers for the armv8 kernel (lots of people running raspbian complain about it).

You need to install a cross-compiler for aarch64 in order to compile modules for the 64bit kernel.

Any thoughts to correcting the issue with the 64bit kernel, or should I stick to 32bit for now?

Just stick to 32bit and don't use raspi-update to update your system.

zaphod24

@mitu

pi@retropie:~ $ lsb_release -a
No LSB modules are available.
Distributor ID: Raspbian
Description: Raspbian GNU/Linux 10 (buster)
Release: 10
Codename: buster

Definitely not bullseye and I haven't used raspi-update to move to a 6.x kernel either:

pi@retropie:~ $ uname -a
Linux retropie 5.10.103-v7l+ #1529 SMP Tue Mar 8 12:24:00 GMT 2022 armv7l GNU/Linux

Thoughts?

mitu

@zaphod24 said in Issue with latest update on RPI4:

Linux retropie 5.10.103-v7l+ #1529 SMP Tue Mar 8 12:24:00 GMT 2022 armv7l GNU/Linux

You're running an arm7vl Linux kernel, but your question was:

... Unfortunately I was not able to build from source as there doesn't appear to be any kernel heavers for the armv8 kernel (lots of people running raspbian complain about it).

armv8 kernel is the 64bit kernel - hence my previous reply.

There are no separate headers for armv8, the headers are in the same package as before (raspberrypi-kernel-headers). If you have an issue building some kernel modules, then post the log files from the module installation - if you used dkms then it will tell you where the build logs are located. Get the log file's contents and post them on pastebin.com, providing the link.

mitu

@zaphod24 You may experience the same issue as https://retropie.org.uk/forum/topic/34200/ - can you check if applying the workaround from that topic helps on your system ?

zaphod24

@mitu I already found/did the workaround of arm_64bit=0. I was just wondering what caused it. From the linked issue, it looks like it was a mistake in buster lite and that will get corrected soon. Definitely not me trying something crazy like a 64bit kernel and 32bit userspace intentionally.

BuZz

@zaphod24 Yeah. It was a mistake. https://forums.raspberrypi.com/viewtopic.php?t=349291&sid=15b0dde0919fc1b822ff7a241b80260c&start=50#p2105775