1 depmod and modprobe 1
2 Optional configuration file /etc/conf.modules 1
3 modprobe 3
4 depmod 3
5 Liste des sp�cifications non class�es 4
1 depmod and modprobe
depmod and modprobe are the components used to make linux
modular kernel manageable from a user or administrator stand
point.
2 Optional configuration file /etc/conf.modules
[config.c,1]
#Specification: /etc/conf.modules / format
Modules may be located at different place in the filesystem.
We expect some standard to emerge. We expect that the
FSSTND will address this in the future.
There will always be some need to override this, especially for
modules developpers.
The file /etc/conf.modules will contain different definition to
control the manipulation of the module.
The format will be fairly simple:
parameter=value
.
parameter=value
Standard Unix style comments and continuation line are supported.
Comments begin with a # and continue until the end of the line.
A line continue on the next one if the last non-white character
is a \.
[config.c,72]
#Specification: /etc/conf.modules / missing
This file is optional. No error is printed if it
is missing. If it is missing the following content
is assumed.
path[boot]=/lib/modules/boot
path[fs]=/lib/modules/`uname -r`/fs
path[misc]=/lib/modules/`uname -r`/misc
path[net]=/lib/modules/`uname -r`/net
path[scsi]=/lib/modules/`uname -r`/scsi
path[fs]=/lib/modules/default/fs
path[misc]=/lib/modules/default/misc
path[net]=/lib/modules/default/net
path[scsi]=/lib/modules/default/scsi
path[fs]=/lib/modules/fs
path[misc]=/lib/modules/misc
path[net]=/lib/modules/net
path[scsi]=/lib/modules/scsi
1
The idea is that modprobe will look first it the
modules compiled for the current release of the kernel.
If not found, it will look into the default release.
And if not found, it will look in the other directory.
The strategy should be like this. When you install a
new linux, the modules should go in a directory
related to the release of the kernel you are installing.
Then you do a symlink default to this directory.
Each time you compile a new kernel, the make modules_install
will set new directory, but won't change de default.
When you get a module unrelated to the kernel distribution
you place it in one of the last three directory.
This is the default strategy. Off course you can overide
this in /etc/conf.modules.
[config.c,152]
#Specification: config file / path parameter
The path parameter specify a directory to
search for module. This parameter may
be repeated multiple time.
Optionally the path parameter carries
a tag. This tells us a little more about
the purpose of this directory and
allows some automated operations.
The tag is sticked to the path word
enclose in square braket.
path[boot]=/lib/modules/boot
This identify the path a of directory
holdding modules loadable a boot time.
Hopefully, insmod will have an option
to load a list of module using
such a tag.
If the tag is missing, the word "misc"
is assumed.
[config.c,210]
#Specification: config file / depfile parameter
The default value for the depfile parameter is:
depfile=/lib/modules/`uname -r`/modules.dep
If the config file exist but lack a depfile
specification, it is used also since the system
can't work without one.
Once we have the depfile value, we pass to the shell
with a popen() to resolve whatever shell construct in
its value. We execute a echo command.
2
echo read_value
[config.c,292]
#Specification: reading directory / ls command
We are using the command ls to locate entries in directories.
This has the advantage of allowing complex wildcard specification
in /etc/conf.modules. For example.
path[misc]=/lib/modules/1.1.5?/misc
[config.c,250]
#Specification: reading directory / ls command / path
The ls command must be either in /bin or /usr/bin.
[config.c,301]
#Specification: reading directory / ls command / default extension
If a search pattern does not have an extension, we add the following
string to the pattern .{mod,o}.
The impact is that modprobe accept argument both with or without
extension.
3 modprobe
[modprobe.c,300]
#Specification: modprobe -r / unknown module
If there is no information about a module in
the dependancy file, we simply call /sbin/rmmod
on the module without further checking.
4 depmod
[depmod.c,46]
#Specification: depmod / kernel syms only
When initialising its symbol table from the kernel
depmod silently discards all symbol from loaded modules.
This means that depmod may be used at any time to compute
the dependancy table, even if there are modules already
loaded.
depmod use the kernel system call to obtain the
symbol table, not /proc/ksyms. depmod assume that
kernel symbols are at the end of the list, just
after a pseudo symbol with a one character name: #
3
5 Liste des sp�cifications non class�es
[module.c,202]
#Sp�cification: etranget�
Pour fabriquer la table de r�solution �vitant un
link multi-passe, on doit recueillir un symbole
par module qui ne serait pas charg� d�s la premi�re
passe.
Lorsqu'un module est charg� par ccld, si au moins
un de ses symboles publiques est d�j� requis par
un module pr�c�dant lui-m�me implicitement requis,
alors ce module sera aussi requis en une passe.
A la fin, les modules non-requis, mais contenant
des symboles requis sont forc�s. Les symboles
externes de ce module deviennent requis (forceant
probablement d'autre modules).
Pour "forcer" un module, on fabrique un source C
temporaire qui r�f�rencera un des symboles publiques
du module.
Une �tranget�: On essai de ne pas choisir de symbole
publique de type "common" parce qu'il ne semble
pas tr�s apte � "forcer" le module.
[module.c,32]
#Sp�cification: librairies / nombre maximum
Un nombre maximum de 255 librairie est permis pour le link