Installer downloads armv7 version for Raspberry Pi OS

[lmbarros]

The installer script decides which arch to download based on uname -m. So, a device running Raspberry Pi OS would install the armv7 version. However, this version will not work, because Raspberry Pi OS is all set up to run binaries compiled to armv6.

[lmbarros]

As a workaround, please go to the balena releases page on GitHub and download a release for armv6l. Then replace /usr/local/bin/balena-engine-dev with the one from the armv6l package you downloaded. This shall get rid of the Illegal Instruction error.

Also, there's one more hiccup you'll probably find next: the current version of balenaEngine do not yet support cgroups v2, so you'll need to configure Raspberry Pi OS to use cgroups v1. To do that, just append systemd.unified_cgroup_hierarchy=0 to the end of the /boot/cmdline.txt in your Pi and reboot. [Edit: cgroups v2 should be working since v20.10.40 -- though we haven't tested in Raspberry Pi OS]