Writing Device Drivers

Critical System Files

A number of driver-related system files are difficult, if not impossible, to reconstruct. Files such as /etc/name_to_major,/etc/driver_aliases, /etc/driver_classes, and /etc/minor_perm can be corrupted if the driver crashes the system during installation (see add_drv(1M)).

To be safe, once the test machine is in the proper configuration, make a backup copy of the root file system. If you plan on modifying the /etc/system file, make a backup copy of the file before modifying it.