Managing and Developing Dynamically Loadable Kernel Modules

Managing Dynamically Loadable Kernel Modules

Chapter 12 515

immediate update will also load the new module.

Step 2. To update the image of a dynamically conﬁgured loadable module at

system shutdown (an asynchronous update), execute the following

kmupdate command:

/usr/sbin/kmupdate -M

module_name

-a

If you do not specify the -i or -a option, kmupdate will attempt to

update the speciﬁed loadable module immediately. If the module cannot

be updated immediately (for example, the current module is in use and

cannot be unloaded), the module will be updated at system shutdown.

Loading a Dynamically Conﬁgured Loadable Module Into the HP-UX

Kernel

To load a dynamically conﬁgured loadable module, use the -L option of

the kmadmin command. The load operation initiated by the kmadmin -L

command performs all tasks associated with link editing the module to

the running kernel and making the module accessible to the system.

NOTE All dynamically loadable modules need to be registered before they can

be demand or autoloaded into the running kernel. The kmupdate

command carries out this task.

Speciﬁcally, the load operation performs the following tasks:

❏ Veriﬁes that the speciﬁed loadable module is registered.

❏ Checks what other modules the loadable module depends on and

automatically loads any such module that is not currently loaded

❏ Allocates space in active memory for the speciﬁed loadable module

❏ Loads the speciﬁed loadable module from the disk and link edits it

into the running kernel

❏ Relocates the loadable module’s symbols and resolves any references

the module makes to external symbols

❏ Calls the module’s _load() entry point to do any module-speciﬁc

initialization and setup

❏ Logically connects the module to the rest of the kernel, which is often

accomplished with the help of module type-speciﬁc installation