% vi tools/build/v2/user-config.jam
using gcc : 4.0 : g++-4.0 : <compileflags>”-arch ppc” <linkflags>”-arch ppc” ;
% bjam toolset=gcc-4.0 –with-regex –with-filesystem –with-iostreams install –prefix=/Users/osana/work-dna/boost/ppc –build-type=complete
[ check the library’s target processor ]
% ar -t libboost_system-gcc40.a
__.SYMDEF SORTED
error_code.o
% ar -x libboost_system-gcc40.a error_code.o
% file error_code.o
error_code.o: Mach-O object ppc
% rm error_code.o
[ cleanup ]
% rm -rf bin.v2
this may sufficient to build another target.