Re: [Boost-users] Cross compiling boost libraries with gcc and using boost jam to crosscompile third-party library (Jambase problem)

From: Vladimir Michl (vladimir.michl_at_[hidden])
Date: 2006-01-12 08:10:43

Hi Stering,

thank you for your ideas.

As looking onto boost web pages, probably the list what you suggested 
boost-build is better to discuss this issue. Going to drop a message
there.

Vlad

On Wed, 2006-01-11 at 08:36 +0100, Stering Wolfram wrote:
> Vladimir,
> 
> >recently I was put into task to cross compile boost for ARM platform
> >with GCC.
> >
> >My building platform is i386 Linux with gcc and cross compiling to arm
> >Linux.
> >  
> >
> 
> I had the very same problem for my Coldfire cross-build (target 
> "m68k-elf"), working under Windows XP using Cygwin.
> I didn't find a "standard way" of doing a cross-build of boost in its 
> build documentation.
> 
> >Standard way for this kind of compilation is, that name of cross
> >compiler (running under i386 but producing arm code) and all cross
> >binary utilities are prefixed by target plarform, so like arm-linux-gcc,
> >arm-linux-g++, arm-linux-ar, arm-linux-objcopy for arm-linux.
> >  
> >
> 
> This applies when using the GNU toolchain.  But nowadays, most cross 
> compilers are gcc based.
> 
> >And this is causing a bit of problem with boost.
> >
> >I can force GCC and GXX, but still have a problem with ar and objcopy.
> >
> >I've tried to setup GCC_BIN_DIRECTORY but it didn't work.
> >  
> >
> 
> I did basically the same thing to tools/build/v1/gcc-tools.jam as you 
> did, at least with respect to ar and objcopy being available as 
> variables that can be set on jam command line.
> I then used "-sGXX=m68k-elf-g++ -sGCC=m68k-elf-gcc -sAR=m68k-elf-ar" on 
> my build command line.
> 
> Additionally, I added support for selecting the CPU model 
> (architecture/instruction-set) by adding the following:
> (I don't know how/why this works, just imitated the respective block for 
> other architectures).
> Perhaps, boost build system should support (kind of) multilib builds for 
> cross compilation, in a similar way that gcc/g++ does when 
> cross-compiling it for targets where this applies?
> 
> This enabled me to add
> "-sBUILD=debug release <runtime-link>static <optimization>size 
> <architecture>m68k <instruction-set>5200"
> to the build command line for a Coldfire cross-build. It even somehow 
> worked, as gcc got called with the correct -m option...
> 
> # Coldfire and other m68k (WS, Tue Dec 20 16:46:10     2005).
> .ARCH = <architecture>m68k <architecture>native ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>default : -m5200 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>68000 : -m68000 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>5200 : -m5200 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>5206e : -m5206e ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>528x : -m528x ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>5307 : -m5307 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>5407 : -m5407 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>cpu32 : -mcpu32 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>68040 : -m68040 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>68060 : -m68060 ;
> flags gcc CFLAGS <architecture>m68k/<instruction-set>soft-float : 
> -msoft-float ;
> 
> >So I've done a small patch to tools/build/v1/gcc-tools.jam adding
> >GCC_PREFIX variable, that if set up, will prefix names of all tools with
> >that prefix.
> >
> >So I can compile boost with 
> >
> >bjam -sTOOLS=gcc -sGCC_PREFIX=arm-linux- stage 
> >  
> >
> 
> Ah, your approach with using GCC_PREFIX is even better!
> Perhaps call it "-sCROSS_TARGET=arm-linux" ?
> 
> >May be it will be useful to add the same functionality to
> >gcc-stlport-tools.jam or mingw.
> >
> >So please find attached changes.
> >
> >It is possible to include them into next boost release?
> >  
> >
> I strongly vote for integrating cross-compilation support (at least 
> using GNU toolchain, after all that's what most use!) in the Boost build 
> system.  But I don't know or use jam or bjam (other than building (parts 
> of) boost itself), so unfortunately I would be of little help... :-(
> I replied to the post becuase somone else might find the information 
> helpful as well, I hope.
> 
> >By the way, the same problem appears when boost jam is used to compile
> >some third-party libraries. Is this place good to talk about boost jam
> >and its Jambase file?
> >  
> >
> Probably move to the boost-build list?
> 
> -wolfi
> 
-- 
Vladimir Michl <vladimir.michl_at_[hidden]>, ICQ# 312939054
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