Installation guide

choosing the kernel option from a menu displayed during processing. You
then shutdown and reboot your system.
To determine which kernel options you can configure in this way, issue the
/usr/sbin/kopt command. The command displays a list of kernel options
and prompts you for kernel options selections. To exit from the
/usr/sbin/kopt command without choosing options, press the Return
key. For information about running the /usr/sbin/doconfig program to
add kernel options using a menu, see Section 5.4.2.
If you build a new static kernel for any other reason, you must modify one
or more system files as part of rebuilding the kernel. The system files you
modify depend upon the change you want to make to the kernel:
• You modify the target configuration file to make changes to keywords
that, for example, define the kernel you want to build, define devices, or
define pseudodevices. You can also edit this file to change the value of
system parameters. For details about the contents of the target
configuration file, see Section 5.5.
• You remove certain static subsystems from the kernel by removing (or
commenting out) their entry from a file in the /usr/sys/conf
directory. For information about this file, see Section 5.5.2.
• You modify the param.c file to change the value of system parameters.
You modify these parameters to tune your system’s performance. For
information about the param.c file, see Section 5.5.3.
Normally, you make these changes using the text editor of your choice
before you begin building the kernel. (Alternatively, you can edit the
system configuration file during the kernel building procedure. However, if
you choose to edit the configuration file during the procedure, define the
EDITOR environment variable to be the editor of your choice. The default
editor is the ed line editor.) For information about running the
/usr/sbin/doconfig program to build a kernel after editing system files,
see Section 5.4.3.
5.4.1 Building the Kernel to Add Support for a New Device
When you add a new device to the system and the device installation
includes no SCP, you must edit the target configuration file to allow the
operating system to support the new device. You include the device
definition keyword in the target configuration file. Because Tru64 UNIX
supports many devices, determining which keyword to add to your target
configuration file can be difficult.
The following procedure explains how to determine which device definition
keyword to add to your target configuration file and how to rebuild the
5–18 Configuring the Kernel