Hi Kai, >> Well I spent yesterday and could not find how to do it. It all ends up in >error >> trying to compile test file with -march=armv6-m but without -mthumb. >Please describe 'compile'... Producing the assembly source and even >the object file should succeed but linking the object with a Thumb-only >C library of course would lead into troubles. Tests with my similar >GCC on Linux built by pure curiosity : When I try to compile C-source file with Code Red LPCXpresso which is shipped with GCC 4.3.3 with -mcpu=cortex-m0 but without -mthumb arm-none-eabi-gcc -I"YYYY" -O0 -g3 -Wall -c -fmessage-length=0 -fno-builtin -ffunction-sections -mcpu=cortex-m0 -MMD -MP -MF"src/XXXX.d" -MT"src/XXXX.d" -o"src/XXXX.o" "../src/XXXX.c" I get the message: ../src/XXXX.c:1: error: target CPU does not support ARM mode make: *** [src/XXXX.o] Error 1 I am pretty sure that it is a compile time error. Adding, or rather restoring since, option -mthumb results in successful production of object file. It is also true that when we build toolchain with --with-mode=thumb then excluding -mthumb does not make compile process fail. Returning back to building toolchain with multilib enabled and default mode --with-mode=arm, I made the following changes to \gcc-4.5.0\gcc\config\arm\t-arm-elf file +MULTILIB_OPTIONS += march=armv6-m mthumb +MULTILIB_DIRNAMES += thumb\/armv6-m +MULTILIB_EXCEPTIONS += *marm*/*march=armv6-m* +MULTILIB_OPTIONS += mno-thumb-interwork/mthumb-interwork +MULTILIB_DIRNAMES += normal interwork +MULTILIB_EXCEPTIONS += *mthumb-interwork*/*march=armv6-m* I would like to think that *marm*/*march=armv6-m* forbids building ARM library when -marmv6-m is present but it does not! The last lines of the `config.log' are (sorry for pasting here so much text): ------------------------------------------------------------------------------------------------------------------------------------ configure:3004: $? = 0 configure:2993: /f/asu/Cortex/gcc-4.5.0/build4/./gcc/xgcc -B/f/asu/Cortex/gcc-4.5.0/build4/./gcc/ -B/f/cross-gcc/4.5.0/arm-none-eabi/bin/ -B/f/cross-gcc/4.5.0/arm-none-eabi/lib/ -isystem /f/cross-gcc/4.5.0/arm-none-eabi/include -isystem /f/cross-gcc/4.5.0/arm-none-eabi/sys-include -march=armv6-m -v >&5 Reading specs from f:/asu/Cortex/gcc-4.5.0/build4/gcc/specs COLLECT_GCC=f:\asu\Cortex\gcc-4.5.0\build4\gcc\xgcc.exe COLLECT_LTO_WRAPPER=f:/asu/Cortex/gcc-4.5.0/build4/gcc/lto-wrapper.exe Target: arm-none-eabi Configured with: ../gcc-4.5.0/configure --target=arm-none-eabi --build=i686-pc-mingw32 --host=i686-pc-mingw32 --prefix=/f/cross-gcc/4.5.0 --disable-nls --disable-shared --disable-threads --with-gnu-gcc --with-gnu-ld --with-gnu-as --with-dwarf2 --enable-languages=c --enable-interwork --enable-multilib --with-gmp=/f/cross-gcc/4.5.0 --with-mpfr=/f/cross-gcc/4.5.0 --with-mpc=/f/cross-gcc/4.5.0 --with-newlib --with-headers=../../newlib-1.18.0/newlib-1.18.0/newlib/libc/include --disable-libssp --disable-libstdcxx-pch --disable-libmudflap --disable-libgomp -v Thread model: single gcc version 4.5.0 (GCC) configure:3004: $? = 0 configure:2993: /f/asu/Cortex/gcc-4.5.0/build4/./gcc/xgcc -B/f/asu/Cortex/gcc-4.5.0/build4/./gcc/ -B/f/cross-gcc/4.5.0/arm-none-eabi/bin/ -B/f/cross-gcc/4.5.0/arm-none-eabi/lib/ -isystem /f/cross-gcc/4.5.0/arm-none-eabi/include -isystem /f/cross-gcc/4.5.0/arm-none-eabi/sys-include -march=armv6-m -V >&5 xgcc.exe: '-V' must come at the start of the command line configure:3004: $? = 1 configure:2993: /f/asu/Cortex/gcc-4.5.0/build4/./gcc/xgcc -B/f/asu/Cortex/gcc-4.5.0/build4/./gcc/ -B/f/cross-gcc/4.5.0/arm-none-eabi/bin/ -B/f/cross-gcc/4.5.0/arm-none-eabi/lib/ -isystem /f/cross-gcc/4.5.0/arm-none-eabi/include -isystem /f/cross-gcc/4.5.0/arm-none-eabi/sys-include -march=armv6-m -qversion >&5 xgcc.exe: unrecognized option '-qversion' xgcc.exe: no input files configure:3004: $? = 1 configure:3020: /f/asu/Cortex/gcc-4.5.0/build4/./gcc/xgcc -B/f/asu/Cortex/gcc-4.5.0/build4/./gcc/ -B/f/cross-gcc/4.5.0/arm-none-eabi/bin/ -B/f/cross-gcc/4.5.0/arm-none-eabi/lib/ -isystem /f/cross-gcc/4.5.0/arm-none-eabi/include -isystem /f/cross-gcc/4.5.0/arm-none-eabi/sys-include -march=armv6-m -o conftest -g -O2 conftest.c >&5 conftest.c:1:0: error: target CPU does not support ARM mode configure:3023: $? = 1 configure:3211: checking for suffix of object files configure:3233: /f/asu/Cortex/gcc-4.5.0/build4/./gcc/xgcc -B/f/asu/Cortex/gcc-4.5.0/build4/./gcc/ -B/f/cross-gcc/4.5.0/arm-none-eabi/bin/ -B/f/cross-gcc/4.5.0/arm-none-eabi/lib/ -isystem /f/cross-gcc/4.5.0/arm-none-eabi/include -isystem /f/cross-gcc/4.5.0/arm-none-eabi/sys-include -march=armv6-m -c -g -O2 conftest.c >&5 conftest.c:1:0: error: target CPU does not support ARM mode configure:3237: $? = 1 configure: failed program was: | /* confdefs.h */ | #define PACKAGE_NAME "GNU C Runtime Library" | #define PACKAGE_TARNAME "libgcc" | #define PACKAGE_VERSION "1.0" | #define PACKAGE_STRING "GNU C Runtime Library 1.0" | #define PACKAGE_BUGREPORT "" | #define PACKAGE_URL "http://www.gnu.org/software/libgcc/"; | /* end confdefs.h. */ | | int | main () | { | | ; | return 0; | } configure:3251: error: in `/f/asu/Cortex/gcc-4.5.0/build4/arm-none-eabi/thumb/armv6-m/libgcc': configure:3254: error: cannot compute suffix of object files: cannot compile See `config.log' for more details.
