On Thu, 2018-06-14 at 14:42 +0200, Claudius Heine wrote:
> Hi Jan,
> 
> On Thu, 2018-06-14 at 14:30 +0200, Jan Kiszka wrote:
> > On 2018-06-14 14:04, Claudius Heine wrote:
> > > Hi,
> > > 
> > > On Wed, 2018-06-13 at 15:07 +0200, Alexander Smirnov wrote:
> > > > Hi all,
> > > > 
> > > > this series introduces basic cross-compilation support for
> > > > Isar.
> > > > The
> > > > implementation
> > > > is based around new entity - buildchroot-cross, which is quite
> > > > similar to original
> > > > buildchroot, but has host architecture.
> > > 
> > > Here is a crazy idea from me and Henning:
> > > Have you tried just installing an amd64-arm cross toolchain into
> > > the
> > > existing arm buildchroot, then switch to it from the 'native'
> > > toolchain
> > > using a combination of PATH variable entries, symlinks and/or
> > > wrapper
> > > scripts and let binfmt deal with calling the amd64 binaries of
> > > the
> > > toolchain in the arm chroot environment?
> > > 
> > > This way the arm system would think that you are compiling
> > > nativly
> > > while in fact you are using a cross compiler that is not
> > > emulated.
> > > 
> > > Would that work?
> > 
> > I just heard some story from SUSE folks doing something probably
> > similar
> > in the past, but they had to patch binfmt to inject the native
> > tools
> > into the chroot.
> > 
> > How would you ensure in your proposal that the native compiler
> > finds
> > its
> > libraries?
> 
> I would try using the wrapper scripts. Setting all the paths to the
> toolchain root directory and then calling gcc and friends with '
> --sysroot /'.
> 
> I would have to try to find out if that works.

There is also chrpath...

As a more conventional method, you could have a cross-buildchroot with
only the cross compiler and distcc and make it that way available to
the buildchroot.

Claudius

> 
> Cheers,
> Claudius
> 
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-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-54 Fax: (+49)-8142-66989-80 Email: ch@denx.de

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