Re: How to generate a cross gcc toolchain that accepts both -m32 and -m64 compiler option?

[Thomas Petazzoni <thomas dot petazzoni at free-electrons dot com>]

Dear Jimm Chen,

On Thu, 20 Nov 2014 00:47:37 +0800, Jimm Chen wrote:
> Using crosstool-ng 1.20, I've managed to build a gcc 4.8.3 cross
> compiler on openSUSE 12.3(32-bit) that is targeted at x86_64(x64)
> linux. The CT-NG tool is a life saver. However, I have a question. the
> generated compiler x86_64-pc-linux-gnu-gcc can only produce x64
> executables. When I try to do
> 
>   x86_64-pc-linux-gnu-gcc -m32 hello.c
> 
> I got error message like:
> 
> /home/chj/x-tools/.../sysroot/usr/include/gnu/stubs.h:7:27: fatal
> error: gnu/stubs-32.h: No such file or directory
>  # include <gnu/stubs-32.h>
>                            ^
> compilation terminated.
> 
> You know, on an openSUSE Linux 64-bit distribution, we can use -m64 to
> produce 64-bit image and -m32 to produce 32-bit image. Can someone
> tell me how to achieve that functionality with CT-NG generated
> toolchain?

You need to look at something called "multilib support". I don't
remember if Crosstool-NG has added multilib support. Last time I
looked, it didn't had multilib support, but maybe it has changed since
then.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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