4. Appendix A: Creating your own initrd
The initrd image is incredibly easy to make - simply download the existing initrd image (see Section 2) and rename it to initrd.cramfs.gz. Unzip it (gunzip initrd.cramfs.gz) and then mount it using the loopback device (e.g. mount -t cramfs -o loop initrd.cramfs /mnt/initrd). Since the cramfs image is read-only, you will need to copy out all of the files before changing/adding any (e.g. cp -av /mnt/initrd/* /tmp/initrd/). Now make any changes you want and run the following commands to remake the image:
chmod -R root.root /tmp/initrd - files must be owned by root.root in the initrd
mkcramfs /tmp/initrd/ /tmp/initrd.cramfs - this makes a new cramfs image from the working directory (you may need to install mkcramfs for this to work)
gzip /tmp/initrd.cramfs - zip the cramfs image to reduce its size
 | What about upgrading the kernel? |
|---|---|
This is not yet a simple process - you will need to put new kernel modules into the initrd, put a new zimage for your kernel into the vfat partition and put the new kernel modules into /lib/modules on your ext3 Intimate partition. We are working on automating this process |