Re: i386 -> x86_64 cross compile failure (binutils bug?)

Andi Kleen
2005-12-11T00:00:49Z

> Here are the relevant lines of arch/x86_64/kernel/vmlinux.lds:
>
> 382 OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64")
> 383 OUTPUT_ARCH(1:x86-64)
> 384 ENTRY(phys_startup_64)
>
> Any ideas? Another toolchain quirk?

The original is

OUTPUT_ARCH(i386:x86-64)

It replaced the i386 with 1, which obviously doesn't work.

Try (full patch again)

-Andi

Pass -m64 by default

This might help on distributions that use a 32bit biarch compiler.

Also add some more .code32s because at least the Ubuntu biarch
32bit gcc doesn't seem to handle -m64 -m32 as generated
by the Makefile without such assistance.

Signed-off-by: Andi Kleen <ak@suse.de>

Index: linux/arch/x86_64/Makefile
===================================================================
--- linux.orig/arch/x86_64/Makefile
+++ linux/arch/x86_64/Makefile
@@ -31,6 +31,7 @@ cflags-$(CONFIG_MK8) += $(call cc-option
cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
CFLAGS += $(cflags-y)

+CFLAGS += -m64
CFLAGS += -mno-red-zone
CFLAGS += -mcmodel=kernel
CFLAGS += -pipe
@@ -52,6 +53,8 @@ CFLAGS += $(call cc-option,-funit-at-a-t
# prevent gcc from generating any FP code by mistake
CFLAGS += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)

+AFLAGS += -m64
+
head-y := arch/x86_64/kernel/head.o arch/x86_64/kernel/head64.o arch/x86_64/kernel/init_task.o

libs-y += arch/x86_64/lib/
Index: linux/arch/x86_64/ia32/vsyscall-sigreturn.S
===================================================================
--- linux.orig/arch/x86_64/ia32/vsyscall-sigreturn.S
+++ linux/arch/x86_64/ia32/vsyscall-sigreturn.S
@@ -7,6 +7,7 @@
* by doing ".balign 32" must match in both versions of the page.
*/

+ .code32
.section .text.sigreturn,"ax"
.balign 32
.globl __kernel_sigreturn
Index: linux/arch/x86_64/ia32/vsyscall-syscall.S
===================================================================
--- linux.orig/arch/x86_64/ia32/vsyscall-syscall.S
+++ linux/arch/x86_64/ia32/vsyscall-syscall.S
@@ -6,6 +6,7 @@
#include <asm/asm-offsets.h>
#include <asm/segment.h>

+ .code32
.text
.section .text.vsyscall,"ax"
.globl __kernel_vsyscall
Index: linux/arch/x86_64/ia32/vsyscall-sysenter.S
===================================================================
--- linux.orig/arch/x86_64/ia32/vsyscall-sysenter.S
+++ linux/arch/x86_64/ia32/vsyscall-sysenter.S
@@ -5,6 +5,7 @@
#include <asm/ia32_unistd.h>
#include <asm/asm-offsets.h>

+ .code32
.text
.section .text.vsyscall,"ax"
.globl __kernel_vsyscall
Index: linux/arch/x86_64/kernel/vmlinux.lds.S
===================================================================
--- linux.orig/arch/x86_64/kernel/vmlinux.lds.S
+++ linux/arch/x86_64/kernel/vmlinux.lds.S
@@ -8,6 +8,8 @@
#include <asm/page.h>
#include <linux/config.h>

+#undef i386 /* in case the preprocessor is a 32bit one */
+
OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64")
OUTPUT_ARCH(i386:x86-64)
ENTRY(phys_startup_64)