I am trying to build an Orange Pi 5 (aarch64) image on my x86 machine with Gentoo. For that, I created a Dockerfile of Ubuntu 22.04 docker image to run the image build script provided.
What I noticed is that when I ran the script without --privileged, the build script would complain things like Unable to mount {/proc,/sys,...} and the qemu-binfmt (which I guess is for binary translation) became extremely slow.
After some digging I found that the build script invokes chroot, enters the newly-built rootfs, and performs some configuration (with qemu-binfmt). Some materials online suggest that --privileged should be added for docker in such a use case.
So, I added the --privilege, and both the complaints and the slowness were gone.
My question is that are these two phenomena connected? Is the slowness caused by the failure of mounting /sys and /proc? Does the qemu-binfmt translation relate to any of these?
Anything would be helpful, like ideas of how to do experiments to verify the connection.
I also did some research on my own, but haven't found something too useful on this matter. Thanks in advance.
