[PATCH] x86_64: fix linking on 32-bit system

[PATCH] x86_64: fix linking on 32-bit system

[Paolo 'Blaisorblade' Giarrusso]

From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>

When compiling a 64-bit kernel on an Ubuntu 6.06 32bit system (whose GCC is also
a cross-compiler for x86_64) I've seen that head.o is compiled as a 64-bit file
(while it should not) and ld complaining about this during linking:

ld: warning: i386:x86-64 architecture of input file
`arch/x86_64/boot/compressed/head.o' is incompatible with i386 output

I've verified that removing -m64 from compilation flags to turn
"-m64 -traditional -m32" into "-traditional -m32" fixes the issue.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/x86_64/boot/compressed/Makefile |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/x86_64/boot/compressed/Makefile b/arch/x86_64/boot/compressed/Makefile
index f89d96f..c6bfd23 100644
--- a/arch/x86_64/boot/compressed/Makefile
+++ b/arch/x86_64/boot/compressed/Makefile
@@ -7,7 +7,9 @@ # Note all the files here are compiled/l
 #
 
 targets		:= vmlinux vmlinux.bin vmlinux.bin.gz head.o misc.o piggy.o
-EXTRA_AFLAGS	:= -traditional -m32
+EXTRA_AFLAGS	:= -traditional
+#Gcc on Ubuntu 6.06 does not cope well with -m64 -m32 - it uses -m64.
+AFLAGS		:= $(subst -m64,-m32,$(AFLAGS))
 
 # cannot use EXTRA_CFLAGS because base CFLAGS contains -mkernel which conflicts with
 # -m32

Re: [PATCH] x86_64: fix linking on 32-bit system

[Andi Kleen]

On Sunday 20 August 2006 16:31, Paolo 'Blaisorblade' Giarrusso wrote:
> From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
> 
> When compiling a 64-bit kernel on an Ubuntu 6.06 32bit system (whose GCC is also
> a cross-compiler for x86_64) I've seen that head.o is compiled as a 64-bit file
> (while it should not) and ld complaining about this during linking:
> 
> ld: warning: i386:x86-64 architecture of input file
> `arch/x86_64/boot/compressed/head.o' is incompatible with i386 output
> 
> I've verified that removing -m64 from compilation flags to turn
> "-m64 -traditional -m32" into "-traditional -m32" fixes the issue.

Applied thanks, but I removed the comment because it's on more
than just Ubuntu 32bit.

AFAIK the warning is harmless, but you're the first to submit a real
patch to fix it.
-Andi