Updated cross binutils and gcc patches against rawhide

[Andy Green]

Hi -

Here are updates I just got working of Lennert and David's patches 
against current rawhide gcc and binutils:

  binutils-2.20.51.0.12-2.fc15.src.rpm
  gcc-4.5.1-5.fc15.src.rpm

which generate updated binutils and gcc cross packages.  The old ones 
are fine except that they're no longer able to build current kernels 
without errors.

They're tested to generate working cross compiler packages on x86_64 
host; the compilers generate a working kernel.org kernel on iMX31 and 
can link a test app with printf() OK, since I just need them for kernel 
compile duties I didn't go any further with cross userspace.


You can use the patches like this:

1) Grab the source RPMs you want to build against

2) cd into your rpmbuild/SOURCES dir and use

   rpm2cpio <source rpm> | cpio -id

to unpack, then mv *.spec ../SPECS

3) patch the binuntils.spec and gcc.spec files with the diffs; they 
should apply cleanly at least with exactly the rawhide sources above

4) rpmbuild -ba --define "binutils_target armv5tel-redhat-linux-gnueabi" 
rpmbuild/SPECS/gcc.spec

5) rpm -i 
rpmbuild/RPMS/x86_64/armv5tel-redhat-linux-gnueabi-binutils-2.20.51.0.12-2.fc15.x86_64.rpm

6) rpmbuild -ba --define="cross_target armv5tel-redhat-linux-gnueabi" 
rpmbuild/SPECS/gcc.spec

7) as root: cd rpmbuild/RPMS/x86_64 ; rpm -Uvf 
armv5tel-redhat-linux-gnueabi-gcc-4.5.1-5.cross12.x86_64.rpm 
armv5tel-redhat-linux-gnueabi-libgcc-4.5.1-5.cross12.x86_64.rpm 
armv5tel-redhat-linux-gnueabi-libgomp-4.5.1-5.cross12.x86_64.rpm 
armv5tel-redhat-linux-gnueabi-cpp-4.5.1-5.cross12.x86_64.rpm 
armv5tel-redhat-linux-gnueabi-libstdc++-4.5.1-5.cross12.x86_64.rpm

8) That's it!

-Andy

[Saleem Ansari]

Hey Andy,

Thanks for sharing these steps.

>  4) rpmbuild -ba --define "binutils_target
> armv5tel-redhat-linux-gnueabi"
>  rpmbuild/SPECS/gcc.spec
>
>  6) rpmbuild -ba --define="cross_target armv5tel-redhat-linux-gnueabi"
>  rpmbuild/SPECS/gcc.spec
>  
Providing cross_target and binutils_target seems to be a neat solution.
However can it be applied to all SRPMs in Fedora universe?

If we can do that, then building packages for ARM would be faster I guess.
( I am not aware of various issues with buidling RPMs using cross compilers.  )

/tuxdna

[Andy Green]

On 12/23/10 13:24, Somebody in the thread at some point said:

Hi -

>  Thanks for sharing these steps. 
You're welcome.

> > 4) rpmbuild -ba --define "binutils_target
> armv5tel-redhat-linux-gnueabi"
> > rpmbuild/SPECS/gcc.spec
> >
> > 6) rpmbuild -ba --define="cross_target armv5tel-redhat-linux-gnueabi"
> > rpmbuild/SPECS/gcc.spec
>
>  Providing cross_target and binutils_target seems to be a neat solution.
>  However can it be applied to all SRPMs in Fedora universe?
>
>  If we can do that, then building packages for ARM would be faster I guess.
>  ( I am not aware of various issues with buidling RPMs using cross compilers.  ) 
Well, the blah_target macros are cheats, actually the spec files for 
those two particularly look for them and act quite differently if 
they're defined.  It has to be done like that because in those cases in 
fact we're cooking host executables which happen to be configured for 
ARM; they're x86_64 executables and packages coming out still at the end 
for example.  They're not actually cross compilation actions which would 
result in an armv5tel package coming out of an x86_64 host.

What you can do generically with rpmbuild for cross is use the 
--target=<arch> option to really get it to cross build and issue <arch> 
packages instead of host ones.  I used this successfully to package the 
cross-built bootloader and kernel for an ARM Fedora-based device earlier 
in the year.

Many packages will eat that OK as well for cross build, it gets passed 
into ./configure and if the package is capable to configure itself to 
cross build it will do so.

However there are enough packages like perl that cannot cleanly build 
cross (it likes to build a "miniperl" executable with which it completes 
the build action; the cross-built miniperl won't work on the host) and 
enough problems from staging cross package installs (%pre and %post 
don't work) that you are way better off doing native build and reserving 
cross for stuff that really needs it like bootloader and kernel.

-Andy

[Henrik Nordström]

tor 2010-12-23 klockan 18:54 +0530 skrev tuxdna:

>  If we can do that, then building packages for ARM would be faster I
> guess.
>  ( I am not aware of various issues with buidling RPMs using cross compilers.  ) 
Semi-cross builds is reasonable. That is an ARM build host using distcc
to hosts of other architectures with suitable cross compilers for
performing the CPU crunching.

Regards
Henrik