Re: [PATCH v2 0/4] x86/boot: Remove runtime relocations from compressed kernel

[Arvind Sankar <nivedita@alum.mit.edu>]

On Tue, May 26, 2020 at 05:07:24PM +0200, Sedat Dilek wrote:
> > >
> >
> > Maybe this should be:
> >
> > [ arch/x86/boot/compressed/Makefile ]
> >
> > -KBUILD_CFLAGS += -include hidden.h
> > +KBUILD_CFLAGS += -include ./hidden.h
> >
> 
> NOPE.
> 
> This works:
> 
> [ arch/x86/boot/compressed/Makefile ]
> 
> -KBUILD_CFLAGS += -include hidden.h
> +KBUILD_CFLAGS += -include ./arch/x86/boot/compressed/hidden.h
> 
> $ ll arch/x86/boot/bzImage arch/x86/boot/compressed/vmlinux
> -rw-r--r-- 1 dileks dileks 6,5M Mai 26 17:05 arch/x86/boot/bzImage
> -rwxr-xr-x 1 dileks dileks 6,5M Mai 26 17:05 arch/x86/boot/compressed/vmlinux
> 
> - Sedat -

It needs to either be $(srctree)/$(src)/hidden.h, or we should add
-I $(srctree)/$(src) to the KBUILD_CFLAGS. The latter option is added
automatically when building in a separate builddir with O=${KOBJ} (which
is how I, and I assume Ard, was testing), but for some reason is not
added when building in-tree. The -include option doesn't automatically
search the directory of the source file.

-include file Process file as if "#include "file"" appeared as the first
line of the primary source file.  However, the first directory searched
for file is the preprocessor's working directory instead of the
directory containing the main source file.  If not found there, it is
searched for in the remainder of the "#include "..."" search chain as
normal.