Comment Re:How do you know? (Score 2) 279
It's possible to remount a file system with new permissions. See the details here:
https://www.gnu.org/software/l...
Or to mount it in a other folder with different permissions.
Or to directly access the partition under
To make a read-only file system work as expected you have to use a hardware way to prevent writing to the memory. For example NOR SPI flash memory usually have a write protection pin. Of course that pin must be protected against unwanted operation that could drive it. In that case you can expect having a clean state after a boot. Secure boot is an other method to give the same kind of clean state after boot.
You still have issues that can live in the SDRAM as long as the device will run...