A school project asked to recompile the Knoppix 3.7 linux-2.4.27 kernel with an added system call.

In order to complete this assignment, we had to first install knoppix onto a new partition on our hard drives. I used hda6 for this partition and installed knoppix by running knoppix-installer. LILO was not installed in the MBR however, it was installed to the partition. My computer was using GRUB, and I added Knoppix to GRUB using chainloader +1 to start up lilo on hda6.

My Computer Paritions are as follows:
hda1 – Windows XP
hda2 – /boot linux ext3 boot
hda3 – linux ext3 (Linux RedHat)
hda5 – Swap
hda6 – Knoppix 3.7

Then source code was taken from http://developer.linuxtag.net/knoppix/sources/
Then, from kernel-source-2.4.27_10.00.Custom_all.deb we extracted the kernel-source-2.4.27.tar.bz2 file inside using Ark. This was then copied over to /usr/src/linux-2.4.27, and the old one was renamed to linux-2.4.27.old. Then inside this directory, we added in our helloworld.c system call inside of the kernel and added it to the Makefile as well. We also added/modified the entry.S and unistd.h files. This system call simply printed out hello world! to the kernel log file. After make dep, make clean, make bzImage (we didn’t need to do make module, but I have tried this already), we then placed the bzImage into the root folder, modified lilo.conf to contain a new entry that referenced this file, and ran lilo. We then rebooted the computer and ran the new kernel and tested the new system call by creating a program that used the call.

The system call used a printk message that would print to a log file, however, it did not print to any of the log files we checked inside of /var/log/ and it’s subdirectories. However, our message did show up when we typed dmesg. This was just one small error compared to what we encountered next.

The school project asked us burn the newly created kernel to a CD. This is where most of our problems came in. We then followed the Knoppix Remastering Howto, http://www.knoppix.net/wiki/Knoppix_Remastering_Howto, with two changes.
• We used /mnt/hda6 as the source for the first ISO image, linux-2.4.27.
• The file created using bzImage, replaces the linux24 file inside the boot/isolinux inside of the master directory.

After doing all of this, we then burned the the ISO using the directions on the Remastering website. When we finally booted the CD onto my computer, it worked great, except that when it was loading, it said that it was loading from the HD…

When we tried to use the CD on another computer, we got the following message:
Kernel Panic VFS: Unable to mount root fs to 03:06

It seems as if this CD is trying to mount on hda6, and since all computers do not have this partition, it’s not able to. After troubleshooting for hours, long sleepeless nights, we got the same error. I tried recompiling the CD from my linux partition on hda3, by chrooting to the source file inside of /knx/source/KNOPPIX/. However, after burning that CD, I got this message:
Kernel Panic VFS: Unable to mount root fs to 03:03


I think that the problem might be that lilo is inside of this partition instead of being installed in the MBR, master boot record. Another problem might be that the fstab file might need some modification. Any ideas? I have been working on this for a long time, and so far, I have created 6 CDs that result in Kernel Panic statements. If anyone has any clue to what the problem might be, please email me!

Other Referenced websites:

Project Description: http://wiggins.cs.uic.edu/cs385/projects/p2/

Silberschatz, A., Galvin, P., Gagne, G. Operating System Concepts. 7th ed. 2005, pp. 74-78.

Knoppix Remastering Howto: http://www.knoppix.net/wiki/Knoppix_Remastering_Howto


--- Sana