keep old kernel source?

jpbarto · 04-07-2003, 03:35 PM

Ok, just built an lfs 4.0 system which of course comes with 2.4.19 kernel. Now built against that is all the lfs software, some libraries from blfs, xf86 and enlightenment. Haven't installed too much else yet. Now again, all that was built against the 2.4.19 kernel. Now if I upgrade to a 2.4.20 or even a 2.5.66 kernel... do I need to keep the old kernel source around? Is any of the software that was compiled against it going to need its header files or anything like that?

Mara · 04-07-2003, 03:40 PM

No, you don't need to keep the old kernel. When you're compiling, it's just important to keep source (or only headers) of current kernels. If possible, also symlink your current source to /usr/src/linux.

mdh · 04-29-2003, 12:19 AM

Nothing will require the headers in the kernel source tree, they should have all been copied over into /usr/include/{asm,asm-generic,linux} before the glibc build.

What is important is that those kernel header files installed into /usr/include are not replaced (even if you upgrade the kernel) as they are the headers your c-libraries were built against

jpbarto · 04-29-2003, 08:32 AM

ok, so I can build / rebuild all the kernels I want... and I can erase any linux-2.x.x source trees I want as long as I don't touch the files I copied over at system creation into /usr/include... ? Thanks.

Mara · 04-29-2003, 02:14 PM

Yes, you can. In my system, /usr/include/linux is a symlink to the corrent directory of my currently-using kernel. With such a configuration, I need to remember every time I delete my kernel sources (it usually means a new kernel) to modify the symlink. Make sure you don't have it configured this way.

mdh · 04-29-2003, 07:29 PM

Quote:

Originally posted by Mara
Yes, you can. In my system, /usr/include/linux is a symlink to the corrent directory of my currently-using kernel. With such a configuration, I need to remember every time I delete my kernel sources (it usually means a new kernel) to modify the symlink. Make sure you don't have it configured this way.

You're heading for trouble doing this, you should NEVER swap out the kernel include files used to build your glibc.

From the venerable book
http://www.linuxfromscratch.org/view...06/kernel.html
scroll to the bottom...

Mara · 05-03-2003, 08:39 AM

mdh, I change my glibc quite often, too. Usually I've got many kernel and many glibc versions in my system...

mdh · 05-04-2003, 09:17 PM

So do I Mara ;-)

Except if there are differing glibc's they go in their own directory (obviously) and are built using the headers from the latest kernel I can find (which are copied into include directory where I put glibc).

The point is that the kernel headers that are referenced during the build of your c-libraries should stay with the c-libraries...