Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Configuring a System
Reconfiguring the Kernel (Prior to HP-UX 11i Version 2)
Chapter 3288
DLKM Concepts
This section provides a conceptual overview of DLKM features and
functionality by:
• defining DLKM at a high level
• explaining terms and concepts essential to understanding DLKM
• describing how DLKM modules are packaged in HP-UX
• identifying the types of kernel modules currently supported by
DLKM
• describing the advantages of writing kernel modules in DLKM
format
• examining DLKM module functions and configuration parameters
What is DLKM? The Dynamically Loadable Kernel Modules
Infrastructure is an HP-UX operating system feature that allows
“DLKM-Enabled” kernel modules to be dynamically loaded into, or
unloaded from, the HP-UX kernel without having to re-link the entire
kernel or reboot the system.
Previously, to install a new driver, you had to edit the system file, run
the config or mk_kernel commands to create a new kernel, shut down
the system, and then bring the system back up before you could use the
new driver.
The DLKM feature not only provides the infrastructure to load kernel
modules into a running system, but it also allows a kernel module to be
statically linked when rebuilding the kernel. Setting a flag in one of the
DLKM module’s configuration files determines whether the module is to
be configured as dynamically loadable or statically linked.
Important Terms and Concepts The DLKM infrastructure allows
kernel modules to be configured in a number of different ways. The
following table considers the different ways a kernel module can be
configured and loaded, and clearly defines each as a term. It also clarifies
the relationship between each term as seen by the HP-UX kernel.