Unable to make SD card filesystem read-only on PI5 with 64bit Bookworm OS.
tried using raspi-config…performance…overlay…and read-only boot settings. It doesnt work. I can still, for example, create a file on the desktop, and after reboot or power-up, the file remains. I have rebooted after setting the raspi-config settings, several times, before testing.
Am I missing something, or is this facility now broken? If broken, is there a work-around?
Unfortunately, that thread does not deal with the same issue. I have found that I can set the file system to read-only using the 32 bit OS, but not with the 64 bit OS.
Has anybody successfully implemented the read-only file system using the full 64 bit Bookworm OS using the prescribed rasppi-config settings?
From what I can gather from that thread Dan shared, the file system not locking correctly is a known issue on more recent Pi OS versions. The method that involves changing settings using raspi-config still works but only to lock the root partition, not the user-accessible section of the SD card like the desktop.
It seems like the line overlayroot="tmpfs" in /etc/overlayroot.local.conf and overlayroot=tmpfs in /boot/cmdline.txt are responsible for controlling this behaviour although I couldn’t find a combination of settings for these values that successfully locked the file system on the most recent version of Bookworm on a Pi 5.
The cmdline.txt file has moved from /boot/cmdline.txt to /boot/firmware/cmdline.txt at some point between versions so this could be responsible for this problem in some way.
Hopefully someone else has more luck getting this to work.
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