Hi Paul, I am building an air-gapped device running on an immutable/ephemeral operating system, hence stringent needs of specific behavior.
Right now, I only want to change bits to make it work as I require. Having my own program packaged as extension & need of display server + webcam support etc, I don't mind using extensions at all, unless you can give me a reason why I shouldn't do things the way I am doing
Not doing automatic backups would not prevent someone manually doing a backup and that would write to your card. You would need to either remove the backup programs, or change the ownership of the files such that you cannot run them. However security on TC is not meant for higher security. For example, user tc is automatically logged in, and user tc has passwordless sudo access. With sudo access someone can easily mount the boot partition and change all of your bootcodes. To change all of this behavior would require editing files that are contained in the initrd. Hence my comment to remaster it.
Good point, but essentially not applicable in my-use case as I would run application in a kiosk mode (1:1 relation for every device with the user, not a public kiosk) with no option of looking around. From what I have heard, its possible to even remove right click context menu so curious users can't get out if they wanted to. Nothing gets stored on the storage medium ever. I have disabled swap, 2nd partition would be auto-unmounted upon boot. Also, no data is actually stored on the storage medium other than the OS + application. Sensitive information is restored in, once it boots up, so unless its the intended user, nobody can do anything even if they physically steal the device in a powered-off state.
And perhaps for some of the customizations, I will be editing files that are in partition 1, which is by definition a remaster, I suppose? I am slowly approaching towards the required behavior step by step, figuring out as I go.
I totally get where you are coming from though. And thanks for raising your concern. If you can still see some concerns, please highlight them, so that I can either amend ways (this is my first time diving this deep into OS layers) or explain why that isn't a concern