i copied the kernel and initrd from installation DVD of open suse 10.2
to my boot folder
#cp openSUSE-10.2-GM-DVD-i386.iso/boot/i386/loader/linux /boot/
#cp openSUSE-10.2-GM-DVD-i386.iso/boot/i386/loader/initrd /boot/

and copied the ISO image of Suse DVD on a partition on hard disk that was completely free

now I booted from kernel image that was copied by the above commands
then I got the graphical installer screen asking me to start installation
by this method I have been able to install Suse in a friends comp without using CDROM or DVD ROM

what I want to know is if instead of the kernel image and initrd image that are on the installation DVD if I put up the kernel image and initrd that already are existing on a system
i.e.
vmlinuz-2.6.18.2-34-default
and initrd-2.6.18.2-34-default

the system does not begin installation

infact it boots into the new kernel on the system.

My question is what is the difference between the kernel images that are on the installation media inside openSUSE-10.2-GM-DVD-i386.iso/boot/i386/loader/
(name linux and initrd )

and the kernel images that are on the system after a fresh installation has taken place inside /boot/ folder
which was able to boot the system instead of starting installation

I think after some search I have got a partial answer to my question
as per the instructions given here
http://www.gentoo.org/doc/en/handboo...?part=1&chap=7

and here
http://linuxfromscratch.org/pipermai...ry/026055.html
I concluded that when linux is being installed on a system for the first time then a generic cd is used to installed which does a
devfs and probes the hardware for the first time
for installation then mounts the initrd
+ if [ "$CHECK_TYPE" = "try_mount" ]; then
+ mount -n -t iso9660 ${cdrom_device} $TMP_MOUNT



and


+ mount -n -o ro -t iso9660 $LFS_CDROM_DEVICE $TMP_MOUNT
+ cd $TMP_MOUNT
+ pivot_root . mnt


and pivot root mounts the root file system and linuxrc script then continues with installation

I need to compile a generic kernel but how to do that ??

Ok so I got what was actually I was searching for I am posting this as a reference if some one by mistake read this and is willing to do same as I did with some other distribution after reading this link go here
http://www.linuxquestions.org/questi...=1#post2935301

you copy the initrd from the distribution DVD and the one on your boot folder inside the system
and do as root
gzip -dc initrd | cpio -id
you will see a lot of directories and some executables
do this for both the initrd's the one on boot folder and the one in installation media
the difference comes in
modules which they load
I am not sure about the udev or devfs which the initrd on installation cd or dvd does .
Actually the difference comes in the init script which you see for both the initrd's the init extracted from the initrd of installation cd or dvd
has a linuxrc script which starts installaion by calling the installer which in my case was yast and in case of fedora is anaconda and debian has its own.
I have tried to explain what ever possible now this should help you.