On 24/06/2019 14:54, Tim Janes wrote:
>
>
> On 24/06/2019 11:52, Jonathan Wakely wrote:
>> On Sun, 23 Jun 2019 at 19:44, Tim Janes <twjanes@xxxxxxxxx> wrote:
>>> I am attempting to build gcc 9.1.0 on an Arm7 (Raspberry Pi) running
>>> piCore Linux distribution, but i wish it to be build to also run on Arm6
>>> (older Pi).
>>>
>>> My build script looks like this
>>>
>>> export CFLAGS="-O2 -pipe -march=armv6zk -mtune=arm1176jzf-s
>>> -mcpu=arm1176jzf-s -mfpu=vfp -mfloat-abi=hard-fuse-ld=gold"
>>> export CXXFLAGS="-O2 -pipe -fno-exceptions -march=armv6zk
>>> -mtune=arm1176jzf-s -mcpu=arm1176jzf-s -mfpu=vfp -mfloat-abi=hard
>>> -fuse-ld=gold"
>>> export LDFLAGS="-L/usr/local/lib"
>>>
>>> ../gcc-9.1.0/configure \
>>> --libdir=/usr/lib \
>>> --enable-shared \
>>> --enable-threads=posix \
>>> --enable-__cxa_atexit \
>>> --enable-c99 \
>>> --enable-long-long \
>>> --enable-clocale=gnu \
>>> --enable-languages=c,c++ \
>>> --disable-multilib \
>>> --disable-libstdcxx-pch \
>>> --enable-cloog-backend=isl \
>>> --with-isl=/usr \
>>> --with-system-zlib \
>>> --enable-frame-pointer \
>>> --disable-bootstrap \
>>> --enable-lto \
>>> --with-pkgversion=piCore \
>>> --with-arch=armv6zk \
>>> --with-tune=arm1176jzf-s \
>>> --with-fpu=vfp \
>>> --with-float=hard \
>>> --with-gxx-include-dir=/usr/include/c++/9.1.0
>>>
>>> but this fails with
>>>
>>> libtool: compile:
>>> /mnt/sda1/piCore/10.x/armv7/tcz/src/gcc/build/./gcc/xgcc
>>> -B/mnt/sda1/piCore/10.x/armv7/tcz/src/gcc/build/./gcc/
>>> -B/usr/local/armv7l-unknown-linux-gnueabihf/bin/
>>> -B/usr/local/armv7l-unknown-linux-gnueabihf/lib/ -isystem
>>> /usr/local/armv7l-unknown-linux-gnueabihf/include -isystem
>>> /usr/local/armv7l-unknown-linux-gnueabihf/sys-include -DHAVE_CONFIG_H
>>> -I../../../gcc-9.1.0/libatomic/config/arm
>>> -I../../../gcc-9.1.0/libatomic/config/linux/arm
>>> -I../../../gcc-9.1.0/libatomic/config/posix
>>> -I../../../gcc-9.1.0/libatomic -I. -Wall -Werror -pthread -g -O2 -pipe
>>> -march=armv6zk -mtune=arm1176jzf-s -mcpu=arm1176jzf-s -mfpu=vfp
>>> -mfloat-abi=hard -fuse-ld=gold -MT load_1_1_.lo -MD -MP -MF
>>> .deps/load_1_1_.lo.Ppo -DN=1 -DIFUNC_ALT=1 -march=armv7-a+fp -c
>>> ../../../gcc-9.1.0/libatomic/config/linux/arm/load_n.c -fPIC -DPIC -o
>>> .libs/load_1_1_.o
>>> cc1: error: switch '-mcpu=arm1176jzf-s' conflicts with '-march=armv7-a'
>>> switch [-Werror]
>>> cc1: all warnings being treated as errors
>>> make[4]: *** [Makefile:854: load_1_1_.lo] Error 1
>>>
>>> How do I stop it picking up march=armv7-a - presumably it is getting
>>> that from the machine I am running on.?
>>>
>>> I have tried adding --with-cpu=arm1176jzf-s to the configuration, with
>>> this I had to remove with-arch and with-tune, but the build gives
>>> exactly the same error.
>>>
>>> Any help or suggestuions would be welcome.
>> GCC assumes you want to build a compiler that runs on the system it's
>> being built. To run on a different system you need to build a
>> cross-compiler, so I think you should use something like:
>>
>> --host=armv6zk-unknown-linux-gnueabihf
>>
>> in the configure arguments.
> Thanks I will try that and let you know if that fixes it.
>
> I am however even more confused, last night I dug out an old arm6
> system, and stared afresh, after 18hours running it has failed with the
> same error, we are running on an arm6 so how is it picking up arm7-a?
>
> cc1: error: switch '-mcpu=arm1176jzf-s' conflicts with '-march=armv7-a'
>
> Tim.
I think this is because your environment variables are interfering with
the build system. Why are you trying to set CFLAGS and CXXFLAGS?
Also, note that in GCC-9 setting -mfpu on the command line should
no-longer be necessary (the -mfpu option now defaults to -mfpu=auto).
The floating-point options can now be derived from the CPU or
architecture specification - see the manual for details. You probably
want to change your configure options to:
../gcc-9.1.0/configure \
--libdir=/usr/lib \
--enable-shared \
--enable-threads=posix \
--enable-__cxa_atexit \
--enable-c99 \
--enable-long-long \
--enable-clocale=gnu \
--enable-languages=c,c++ \
--disable-multilib \
--disable-libstdcxx-pch \
--enable-cloog-backend=isl \
--with-isl=/usr \
--with-system-zlib \
--enable-frame-pointer \
--disable-bootstrap \
--enable-lto \
--with-pkgversion=piCore \
--with-arch=armv6zk+fp \
--with-tune=arm1176jzf-s \
--with-float=hard \
--with-gxx-include-dir=/usr/include/c++/9.1.0
If you do this, and get rid of the environment variables, then the
result after a 3-stage bootstrap should be compatible with your Arm6
based Pi.
R.
