[CentOS] Adding a kernel module to the ISO/installer initrd?

[Tim Nelson]

----- "Karanbir Singh" <mail-lists at karan.org> wrote:
> On 05/29/2009 03:34 PM, Tim Nelson wrote:
> > Surely someone has rebuilt the initrd for the installer ISO? I
> recall seeing something on the list about it previously in regards to
> storage controllers but I cannot seem to find it now...
> 
> yes, plenty of times.
> 
> > Is there somewhere I can look to see the original mkinitrd command
> used to build the initrd on the ISO? I could then ensure I have all of
> the modules specified there along with my additional module.
> 
> the initrd isnt built with the normal mkinitrd command on a running 
> machine, you need to have a lot of the installer components setup to 
> include ( remember that the first 25% of the installer is actually in
> 
> the initrd ).

Ahhh... I did not know that parts of the installer live within the initrd itself...

> 
> Your best process here is to grab the existing initrd, push your
> modules 
> into that, and repack it. You should not need to do much more beyond
> add 
> the right pciid's and the modules to the right place, depmod it so the
> 

How does one put additional modules into an existing initrd? Is there a way to "unpack" it, add the module, and do a "repack"? On my first creation of an initrd with the proper module added, I did see the NIC's properly detected upon boot so I don't believe I'll need to mess with the PCI ID's do I?

After the "unpack" would I be presented with a rootfs type system to chroot into for making changes? I'm *VERY* hazy on the initrd inner workings...

> modules info is updated and repack.
> 
> give it a shot, I'll help you along if you get stuck. once you are
> done, 
> will you write up the process for us ?
> 

I'd absolutely be willing to write up the process. The best place would be the wiki correct?

--Tim