CentOS - Feb 2007 - RPM rebuild, cross compiling from x86 to x86_64

Hi

I want to recompile some RPMs (my own) for x86_64 arch from my i386
compatible build host (because of hardware restriction/funds).Is anyone
ever done this ? After a google search, it seems not so easy... i just
found this: http://www.speedblue.org/cross_compilation/ but haven't
tried it yet (i would have to convert these to RPM first).

How is it done for Centos SRPMS rebuilds ? is it a different
hardware for each target arch ?


Thanks !

-- 
Martin

You need the src rpm for the package you want to compile

-----Original Message-----
From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On
Behalf
Of Martin Hamant
Sent: Friday, February 16, 2007 11:54 AM
To: CentOS mailing list
Subject: [CentOS] RPM rebuild, cross compiling from x86 to x86_64

Hi

I want to recompile some RPMs (my own) for x86_64 arch from my i386
compatible build host (because of hardware restriction/funds).Is anyone
ever done this ? After a google search, it seems not so easy... i just
found this: http://www.speedblue.org/cross_compilation/ but haven't
tried it yet (i would have to convert these to RPM first).

How is it done for Centos SRPMS rebuilds ? is it a different
hardware for each target arch ?


Thanks !

-- 
Martin
_______________________________________________
CentOS mailing list
CentOS at centos.org
http://lists.centos.org/mailman/listinfo/centos

On Fri, 2007-02-16 at 16:53 +0100, Martin Hamant wrote:
> Hi
> 
> I want to recompile some RPMs (my own) for x86_64 arch from my i386
> compatible build host (because of hardware restriction/funds).Is anyone
> ever done this ? After a google search, it seems not so easy... i just
> found this: http://www.speedblue.org/cross_compilation/ but haven't
> tried it yet (i would have to convert these to RPM first).
> 
> How is it done for Centos SRPMS rebuilds ? is it a different
> hardware for each target arch ?
This will not be easy to do.

You can fairly easily build a cross compiler ... HOWEVER

You are also going to need to install packages that are BuildRequires
for the packages that you want to build (so you can compile against
them) ... and the xxxxxxx-devel.x86_64 files (the ones with the headers)
are going to all REQUIRE the xxxxxxx.x86_64 packages too.

It is almost impossible to do this without installing the x86_64
distro ... and that requires an x86_64 capable processor.

You might be able to emulate it (maybe qemu), but by the time you do
that it would have been cheaper and easier to have spent $300.00 and
obtained a cheap machine to do it on.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL:
<http://lists.centos.org/pipermail/centos/attachments/20070216/c5cc2856/attachment.sig>

Johnny Hughes wrote:
> On Fri, 2007-02-16 at 16:53 +0100, Martin Hamant wrote:
>> Hi
>>
>> I want to recompile some RPMs (my own) for x86_64 arch from my i386
>> compatible build host (because of hardware restriction/funds).Is anyone
>> ever done this ? After a google search, it seems not so easy... i just
>> found this: http://www.speedblue.org/cross_compilation/ but haven't
>> tried it yet (i would have to convert these to RPM first).
>>
>> How is it done for Centos SRPMS rebuilds ? is it a different
>> hardware for each target arch ?
> 
> This will not be easy to do.
> 
> You can fairly easily build a cross compiler ... HOWEVER
> 
> You are also going to need to install packages that are BuildRequires
> for the packages that you want to build (so you can compile against
> them) ... and the xxxxxxx-devel.x86_64 files (the ones with the headers)
> are going to all REQUIRE the xxxxxxx.x86_64 packages too.
> 
> It is almost impossible to do this without installing the x86_64
> distro ... and that requires an x86_64 capable processor.
> 
> You might be able to emulate it (maybe qemu), but by the time you do
> that it would have been cheaper and easier to have spent $300.00 and
> obtained a cheap machine to do it on.
It might also be possible to build a cross compiler, then do your "make 
&& make install" from the source tree to put the binaries
someplace,
maybe /tmp/Build/package, and to construct a spec file that will take 
those binaries and create an rpm using those as "data" files. It's
the
sort of thing you'd do to transform a tarball of proprietary binaries 
into an rpm.

In the build environment, you do away with all the benefits of rpm, but 
it might work.




-- 

Cheers
John

-- spambait
1aaaaaaa at coco.merseine.nu  Z1aaaaaaa at coco.merseine.nu

Please do not reply off-list