How to build a driver disk for an anaconda install (CentOS 6)

I may have found my answer in the anaconda source after all.

To generate a CentOS 6 compatible driver disk, you can create a squashfs image (other filesystems might also work, but squashfs is by far the easiest to create) with the following layout:

• rhdd3 - a file with a simple one-line comment to describe the disk
• .rundepmod - the presence of this file tells the installer that it should run depmod in order to pick up the modules
• rpms/x86_64 - an optional yum repository containing the kmod RPMs
• lib/modules/2.6.32-220.el6.x86_64/... - the actual kernel modules go here; if the driver disk contains an updated driver of an upstream driver, then the directory structure here should match the upstream kernel module location. The version of the kernel should of course match the version of the installer.

And since a picture is worth a thousand words, here is the sample driver disk we use to kickstart recent laptops that need an updated atl1c.ko driver:

$ unsquashfs -ls driver-disk.dd 
Parallel unsquashfs: Using 2 processors
8 inodes (26 blocks) to write

squashfs-root
squashfs-root/.rundepmod
squashfs-root/lib
squashfs-root/lib/modules
squashfs-root/lib/modules/2.6.32-220.el6.x86_64
squashfs-root/lib/modules/2.6.32-220.el6.x86_64/kernel
squashfs-root/lib/modules/2.6.32-220.el6.x86_64/kernel/drivers
squashfs-root/lib/modules/2.6.32-220.el6.x86_64/kernel/drivers/net
squashfs-root/lib/modules/2.6.32-220.el6.x86_64/kernel/drivers/net/atl1c
squashfs-root/lib/modules/2.6.32-220.el6.x86_64/kernel/drivers/net/atl1c/atl1c.ko
squashfs-root/lib/modules/2.6.32-220.el6.x86_64/updates
squashfs-root/rhdd3
squashfs-root/rpms
squashfs-root/rpms/x86_64
squashfs-root/rpms/x86_64/kmod-compat-wireless-3.3_2_n-2.el6.x86_64.rpm
squashfs-root/rpms/x86_64/repodata
squashfs-root/rpms/x86_64/repodata/filelists.xml.gz
squashfs-root/rpms/x86_64/repodata/other.xml.gz
squashfs-root/rpms/x86_64/repodata/primary.xml.gz
squashfs-root/rpms/x86_64/repodata/repomd.xml