llvm dev - Jul 2012 - [LLVMdev] Setting up a cross-compiler for cortex-m3

On 18 July 2012 14:33, salvatore benedetto
<salvatore.benedetto at gmail.com> wrote:
> but I still haven't figure out how to build for cortex-m3
>
> clang -march=armv7-m -mfloat-abi=soft <something missing?>
testReference.cpp -c
-march should have done the trick.

You can also try -mcpu=cortex-m3,

or try -ccc-host-triple armv7m-none-gnueabi (or -eabi),

and possibly -ccc-gcc-name code sourcery's gcc,

or possibly --sysroot=code sourcery/libc

-- 
cheers,
--renato

http://systemcall.org/

On Wed, Jul 18, 2012 at 3:52 PM, Renato Golin <rengolin at systemcall.org>
wrote:
> On 18 July 2012 14:33, salvatore benedetto
> <salvatore.benedetto at gmail.com> wrote:
>> but I still haven't figure out how to build for cortex-m3
>>
>> clang -march=armv7-m -mfloat-abi=soft <something missing?>
testReference.cpp -c
>
> -march should have done the trick.
>
> You can also try -mcpu=cortex-m3,
>
> or try -ccc-host-triple armv7m-none-gnueabi (or -eabi),
I've tried with all of the following

$ clang -march=armv7-m -mfloat-abi=soft -triple thumb2-unknown-unknown
-integrated-as testReference.cpp -c
clang: warning: argument unused during compilation: '-mfloat-abi=soft'
clang: warning: argument unused during compilation: '-triple
thumb2-unknown-unknown'
error: unknown target CPU 'armv7-m'

$ clang -march=armv7-m -mfloat-abi=soft -mcpu=cortex-m3 testReference.cpp -c
clang: warning: argument unused during compilation: '-mfloat-abi=soft'
clang: warning: argument unused during compilation: '-mcpu=cortex-m3'
error: unknown target CPU 'armv7-m'

$ clang -mcpu=cortex-m3 testReference.cpp -c
clang: warning: argument unused during compilation: '-mcpu=cortex-m3'

$ clang -march=armv7-m -mfloat-abi=soft -ccc-host-triple
armv7m-none-gnueabi testReference.cpp -c
fatal error: error in backend: CPU: 'cortex-m3' does not support ARM
mode execution!
> and possibly -ccc-gcc-name code sourcery's gcc,
>
> or possibly --sysroot=code sourcery/libc
I guess those would be used for the linking part?

Anyway thanks for your rapid response.

S.

On 18 July 2012 14:57, salvatore benedetto
<salvatore.benedetto at gmail.com> wrote:
> $ clang -march=armv7-m -mfloat-abi=soft -ccc-host-triple
> armv7m-none-gnueabi testReference.cpp -c
> fatal error: error in backend: CPU: 'cortex-m3' does not support
ARM
> mode execution!
Ah, yes! Try:

$ clang -ccc-host-triple thumbv7m-none-gnueabi testReference.cpp -c

Cross compilation in Clang is very broken at the moment. There was
some effort to fix this last year, but I guess it lost momentum...

-- 
cheers,
--renato

http://systemcall.org/