Specifications

D
evice Driver Programming
14-22
Documenting Your Driver Installation 14
If you are developing a DSP to be installed by users who might not be familiar with the
implications of reconfiguration, some words of caution might be worthwhile.
• Although experience has shown little difficulty in installing and removing a
variety of device drivers, there is the possibility that you might have diffi-
culty booting the system. The cause of this probably would be due to some
fault in the added driver. If this occurs, you might have to restore the UNIX
system kernel from the saved version.
• Do not halt the system during installation. Although interruption protection
is built into the idtools scheme, total protection against a reboot during an
installation can never be completely foolproof.
• Use the df command in your script or advise your users to run df to deter-
mine the free disk space before doing the installation. If there is not enough
space to install the DSP, tell the user how much space needs to be freed up.
If you require the users to check for themselves, tell them how many free
blocks are needed to install the DSP.
• Similarly, if your script exits because idspace has revealed that there is
not enough space to reconfigure the kernel, tell the user how many blocks
are needed.
• Advise the user not to have any background processes running that con-
sume free disk space while a reconfiguration is underway. For example,
avoid running uucp during an installation.