The "config.txt" has moved from /boot/config.txt to /boot/firmware/config.txt for bookworm based releases. The old file has been updated to reflect this:

cat /boot/config.txt

DO NOT EDIT THIS FILE

The file you are looking for has moved to /boot/firmware/config.txt

Other than the updated location, the content looks the same to me. More info here: https://www.raspberrypi.com/documentation/computers/config_txt.html.

This affects quite a few modules. A quick search through the repository found these:

• common.sh
• base
• gui
• raspicam
• usbconsole

I propose that these modules are updated such that the location of "config.txt" is stored in a variable that can be set or resolved based on the Raspberry PI OS release.