Managing and Developing Dynamically Loadable Kernel Modules

Managing Dynamically Loadable Kernel Modules

Chapter 12508

are installed on the system. Furthermore, the format of such information

is subject to change. Using the kmsystem(1M) and kmtune(1M)

commands to modify the planned conﬁguration prior to a whole kernel

conﬁguration or a module conﬁguration will avoid corruption of the

conﬁguration ﬁles, and will ensure that the correct ﬁles are updated.

CAUTION Avoid editing the system ﬁles; doing so is not forward-compatible and

increases the chance of introducing conﬁguration errors.

In addition, a conﬁgured, bootable kernel is no longer composed of a

single ﬁle. Each new kernel conﬁgured with the config(1M) or

mk_kernel(1M) command is composed of several ﬁles, including the

main kernel ﬁle, the loadable images for DLKMs, a symbol table ﬁle, and

a kernel-speciﬁc KRS ﬁle. All component ﬁles of the kernel are essential

for the kernel to boot and run properly. The kmupdate(1M) command

understands the organization of these ﬁles and prepares a directory

structure accessible to the boot loader that allows a newly generated

kernel to boot and run properly.

A whole kernel conﬁguration must be followed by a kernel update step

initiated via the kmupdate(1M) command (or config -u) in order to be

able to successfully boot the new kernel.

Because of these effects, it is best to conﬁgure any type of kernel module

using the tools described in this section.

CAUTION Avoid copying or moving kernel ﬁles; doing so may result in corrupting

the running kernel, or any other conﬁgured kernel on the system.

See kmsystem(1M), kmtune(1M), mk_kernel(1M), config(1M), and

kmupdate(1M) for more information.

DLKM Procedures

This section explains how to conﬁgure, load, and unload DLKM-enabled

kernel modules. Procedural information is shown in two different ways.

The ﬁrst is a summary and the second provides the details.

1. DLKM Procedural Flowchart