kernel headers files difference

kushalkoolwal · 07-03-2009, 03:44 PM

I usually custom compile my kernel and generate the header files with the following command:

Code:

fakeroot make-kpkg --initrd --append-to-version=generic-ide kenrel_image kernel_headers

However, I noticed that there are some difference in the headers files that get generated with the above command as compared to the header files that are available from Debian repo.

For example, the header files for 2.6.24 kernel have files like:

Code:

debian:/usr/src/linux-headers-2.6.24-etchnhalf.1-686/arch/x86# ls
Kconfig  Kconfig.cpu  Kconfig.debug  kernel  Makefile  Makefile_32  Makefile_32.cpu  Makefile_64

However, if I custom compile the above kernel from Debian sources (2.6.24), the headers files does not have the above files:

Code:

debain:/usr/src/linux-headers-2.6.24-generic-ide/arch/x86# ls
boot    ia32     Kconfig.cpu    kernel  lib           mach-es7000   mach-visws    Makefile     mm        pci    vdso   xen
crypto  Kconfig  Kconfig.debug  lguest  mach-default  mach-generic  mach-voyager  math-emu         oprofile  power  video

As you can see from above output, files like Makefile_32, Makefile_32.cpu are not present, if I generate kernel headers files using the make-kpkg command as mentioned in the beginning of the post.

I happened to notice the above issue, while I was trying to compile a out-of-tree kernel module and the "make" command for those sources (some graphics card drm module) worked with the default header files (linux-headers-2.6.24-etchnhalf.1-686) but did not work with (linux-headers-2.6.24-generic-ide) because it did not find the Makefile_32.

Although I was able to fix the problem by copying the Makefile_32 from linux-headers-2.6.24-etchnhalf.1-686 but I would like to know why there is a difference. This is bit of a concern because it unnecessarily breaks the out-of-tree module compilation process because of trivial reasons.

Can anybody throw some light on this?

Quakeboy02 · 07-05-2009, 12:14 AM

I can't help you with your question, but do you really need to generate a new set of kernel headers? If so, why? Normally, you don't need to do that, unless you're planning to remove the source code and still need to have access to the headers.

kushalkoolwal · 07-05-2009, 02:41 AM

Quote:

Originally Posted by Quakeboy02

Normally, you don't need to do that, unless you're planning to remove the source code and still need to have access to the headers.

Yes, I am exactly doing the same. Removing the source code but still providing access to header files for out of tree module compilation. Don't ask me why I am doing this. There are several reasons but that's a complete different topic.

makuyl · 07-05-2009, 03:25 AM

This still about the ide-generic I take it.
Either you don't have correct header targets in /yourkernelsrcpath/debian/ruleset/targets/headers.mk, you've stumbled across the packaging bug from the x86 architecture merge, or your kernel-package is lacking one of the following lines:

Code:

:~$cat /usr/share/kernel-package/ruleset/targets/headers.mk |sed -n '83,97p'
######################################################################
        $(install_file) Makefile                           $(SRCDIR)
        test ! -e Rules.make || $(install_file) Rules.make $(SRCDIR)
        test ! -e .kernelrelease || $(install_file) .kernelrelease $(SRCDIR)
        test ! -e arch/$(LINK_ARCH)/Makefile     ||                             \
                                $(install_file) arch/$(LINK_ARCH)/Makefile      \
                                                     $(SRCDIR)/arch/$(LINK_ARCH)
        test ! -e arch/$(LINK_ARCH)/Makefile.cpu ||                             \
                                $(install_file) arch/$(LINK_ARCH)/Makefile.cpu  \
                                                     $(SRCDIR)/arch/$(LINK_ARCH)
        test ! -e arch/$(LINK_ARCH)/Makefile_32.cpu ||                             \
                                $(install_file) arch/$(LINK_ARCH)/Makefile_32.cpu  \
                                                     $(SRCDIR)/arch/$(LINK_ARCH)
        test ! -e Rules.make     || $(install_file) Rules.make     $(SRCDIR)
        test ! -e Module.symvers || $(install_file) Module.symvers $(SRCDIR)

kushalkoolwal · 07-05-2009, 03:39 AM

Quote:

Originally Posted by makuyl

This still about the ide-generic I take it.

Actually it is not. I just used a name (generic-ide) for the kernel as an example. This is a completely different issue and I have been observing this behavior for quite some time (even with 2.6.25 I think).