HOWTO: Customising/Upgrading the Kernel - An Evolving HowTo

[knopx4me]

Thanks alot for this great howto. I managed to get my 1st kernel on live CD. I obtained kernel 2.6.14-3 sources from here:
http://www.kernel.org/
and used Kanotix 2005-03 config file to configure it. I used cloop sources from here:
http://debian-knoppix.alioth.debian.org/sources/
My live CD is working perfictly. Now, I will start adding drivers to my remaster.

However, I do not know how to add kernel headers to my live CD since this is not a debian kernel source. Do you have an idea how to do that?

[tr]

That being said this HOWTO is aimed to replace the kernel using a more traditional method, rather than make-kpkg. Unless you experience these problems having followed the HOWTO as written, it can not be improved to ensure others don't experience similar obstacles.

Thus I would request that you attempt to compile using the methods detailed, and report your errors based on them, then I can provide better assistance.

There's no difference if you use 'make' or 'make-kpkg kernel_image' to compile kernel and its modules (same error messages). I just like more of Debian way to compile kernel with make-kpkg. Also installing .deb packages is very simple and secure Only thing to remember is that 'make-kpkg clean' cleans also asm symlink from include sub-directory so it must be created again (ln -s asm-i386 asm).

So my problem was NOT the method itself but something else I still actually don't know. I can compile fine in my old Athlon 1300 MHz machine with 768 MB RAM but NOT in my 64-bit Atllon 3000+ machine with 2 GB RAM. So I think this must have something to do with 64-bit AMD processor. (?)

Now I have 2.6.15-rc4 kernel from Debian source with unionfs 1.0.14 and cloop 2.02 (Used Debian kernel because Knoppix is Debian based and Debian kernels are patched already)

Thank you, firmsy, of your howto and also of initRAMFS howto. Using initramfs helped much (no need to shrink unionfs. module).

-tapsa-

[sakiZ]

This is a most interesting discussion.

I have no interest in making a new CD. My interest is upgrading the 2.6.9 kernel in my Knoppix 3.7 HDD install.

Since I don't want 3 kernels in the OS, I want to remove the (buggy) 2.6.9 kernel. The venerable 2.4.27 kernel will stay -- for now.

I have downloaded the newest 2.6.15 kernel. How do I proceed?

I have never done anything like this before.

sakiZ

[pracsec]

In order to fit the very large unionfs.ko module, it would seem reasonable to extend the initrd image, minirt.gz.


Any thoughts on why this is good or bad for Knoppix?

[firnsy]

In order to fit the very large unionfs.ko module, it would seem reasonable to extend the initrd image, minirt.gz.


Any thoughts on why this is good or bad for Knoppix?

When originally working with new kernels and unionfs I just extended the initrd image. This was fine, but I was getting sick and tired of the uncompressing, loopback mounting, copying, unmounting, compressing cycle. It wasn't until I found the alternate initRAMFS structure, this is essentially dynamic in size in that it doesn't require you to allocate the space for all the files.

Checkout my other HOWTO at http://www.knoppix.net/forum/viewtopic.php?t=22271

[pracsec]

In order to fit the very large unionfs.ko module, it would seem reasonable to extend the initrd image, minirt.gz.


Any thoughts on why this is good or bad for Knoppix?

When originally working with new kernels and unionfs I just extended the initrd image. This was fine, but I was getting sick and tired of the uncompressing, loopback mounting, copying, unmounting, compressing cycle. It wasn't until I found the alternate initRAMFS structure, this is essentially dynamic in size in that it doesn't require you to allocate the space for all the files.

Checkout my other HOWTO at http://www.knoppix.net/forum/viewtopic.php?t=22271

Firnsy, I agree - it is tiring. I'll give your HOWTO a try and report back. Also, I think I can add some of my experience to this HOWTO. I just need to gather up my notes and get them in usable form.

[doktorn]

Hello,

I'm about to put Xen-patched kernel 2.6.15 on a Knoppix CD for out LiveCD router simulator project. I've compiled a kernel that starts just fine (booted the CD-Rom but chose to load kernel from harddrive, which is possible thanks til GRUB). However, just that it starts and everything *seems* alright doesn't mean it is

As stated, the kernel is not knoppix-patched in any way. And that is because... I've never been into knoppix remastering until now. So, my questions are quite simple:

Are there and knoppix-patches to kernel that I really should apply? Or is a debian-kernel (which Xen-kernel is derived from) just fine?

I've heard something about patching the size of the kernel parameter (/proc/cmdline) because of the massive options list a Knoppix LiveCD can use. How about that?

Oh, and while I'm on the topic. I've had some fights with unionfs.ko before I got it all right. The size of the file was somewhere around 5.4MB. Stripping it, or compiling without -g in Makefile, made it smaller (2,4MB). But when I tried to load it, I got "Invalid module format". So I just made my miniroot larger, and put the unstripped version there. It loads just fine.

[firnsy]

Hello,

I'm about to put Xen-patched kernel 2.6.15 on a Knoppix CD for out LiveCD router simulator project. I've compiled a kernel that starts just fine (booted the CD-Rom but chose to load kernel from harddrive, which is possible thanks til GRUB). However, just that it starts and everything *seems* alright doesn't mean it is

As stated, the kernel is not knoppix-patched in any way. And that is because... I've never been into knoppix remastering until now. So, my questions are quite simple:

Are there and knoppix-patches to kernel that I really should apply? Or is a debian-kernel (which Xen-kernel is derived from) just fine?

I've heard something about patching the size of the kernel parameter (/proc/cmdline) because of the massive options list a Knoppix LiveCD can use. How about that?

Oh, and while I'm on the topic. I've had some fights with unionfs.ko before I got it all right. The size of the file was somewhere around 5.4MB. Stripping it, or compiling without -g in Makefile, made it smaller (2,4MB). But when I tried to load it, I got "Invalid module format". So I just made my miniroot larger, and put the unstripped version there. It loads just fine.

Essentially the only remaining knoppix patch, if you could call it that, would indeed be the extension of the command line from default 256 characters up to 512. To tell you the truth I don't remember to do that everytime I recompile a new kernel (currently using 2.6.15.2).

It is true that unionfs can cause grief when stripped, although similarly to the kernel, I like to maintain cutting edge with this and the current snapshot of unionfs compiles to about 400k without debugging, so there are some definant improvements from that end.

[tr]

Essentially the only remaining knoppix patch, if you could call it that, would indeed be the extension of the command line from default 256 characters up to 512. To tell you the truth I don't remember to do that everytime I recompile a new kernel (currently using 2.6.15.2).
.

I don't use that patch either because only very rarely (or never) you need more than 256 characters in command line in remastered version.

I use also 2.6.15.2 kernel from kernel.org at this time and unionfs from Debian unstable. If someone has problems in compiling, my files can be used from http://tapsa.terae.net/linux/knoppix...inux-2.6.15.2/. There's also corrected minirt.gz file (usb2 patch) and instructions how to get initRAMFS unzipped (using it according firmsy's howto). I have translated 'Welcome to Knoppix-live-DVD' in finnish - so please, use yor own language and repack minirt.gz again.


-tapsa-

[meatwad]

So does anyone know why the Knoppix unionfs.ko module is only 77k in size and the ones all of us seem to be building are MUCH larger? (My most recent was 5.5Mb unstripped).