doc_modules

SLAX/FanX制作livecd的完全脚本

How to create own modules for your LiveCD
-----------------------------------------

To create a module for your LiveCD, create an empty
directory somewhere, for example in /tmp/newmod.

Then create the essential module content in this directory.
Each module should contain these files:

  ./preinsert     # /tmp/newmod/preinsert
  ./postinsert    # /tmp/newmod/postinsert
  ./manual        # /tmp/newmod/manual

and it should contain these directories:

  ./data          # /tmp/newmod/data/

The directory ./data should contain the whole filesystem
(all changed or new files and directories). Let's assume
that ./data is the new root here, so if you wish to include
/bin/bash in your module, place it in ./data/bin/bash
(or in /tmp/newmod/data/bin/bash in this example).

The content of ./data directory could be created from
slackware's TGZ package by using "installpkg -root ./data packagename.tgz"
(or by "installpkg -root /tmp/newmod/data/ packagename.tgz" in this example)

Finaly, create the module by using
dir2img /tmp/newmod/ /tmp/modulename.img
The first argument is the module directory
The second argument is the new name for your module


Module insertion works this way
-------------------------------

At first, module is mounted in /mnt/livecd/modulename
and preinsert file is started - only in the case it's
marked as executable, so be sure to chmod it correctly
(for example by using chmod a+x preinsert).

Then, the whole filesystem from ./data is inserted in
the Live filesystem. For example ./data/bin/bash will become
/bin/bash, etc. This insertion is done by using symlinks
(for new files) and by mount calls with "--rbind" option
(for new directories).

Finaly, postinsert file is started (if marked as executable)
to perform some post-insertion operations.

What is ./manual file for? Normally, the module is inserted
at the boot phase, so all your modified or new rc-scripts
are started by your distribution automatically. The problem
is with including the module by using moduse script.
./manual is executed only in the case if the module is included
by moduse tool, so it should contain all commands neccessary
to start appropriate rc-scripts automatically.


Note
----

Please keep the number of your modules as small as possible.
Each inserted module could consume alot of resources (several
mount calls, several loop devices and lots of symlinks), so it's always
better to include all files you wish in a single module.
10 modules is OK, but 1000 modules is not ok.