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

Hi there,

I'm trying to switch from GCC to llvm (clang++) for cross-compiling
a firmware of mine for a stm32 (ARM cortex-m3).

After looking in the documentation and a bit of googling here is what
I did (in case someone else in the future is having the same problem)

cd llvm
git clone http://llvm.org/git/llvm.git

cd llvm/tools
git clone http://llvm.org/git/clang.git

cd llvm/projects
git clone http://llvm.org/git/compiler-rt.git

cd ../llvm-build/
../llvm/configure --prefix=$(HOME)/bin/llvm
--exec-prefix=$(HOME)/bin/llvm  --enable-targets=x86_64,arm,cpp
--enable-optimized

make
make install

It seems everything compiled smoothly, but I can't figure out if there
is any options that list all available targets.
The following only display my host platform as target.

clang -v
clang version 3.2 (http://llvm.org/git/clang.git
88237bf587581026dcfc8386abf055cb201aa487)
(http://llvm.org/git/llvm.git
18a1b616ea123548b61a037c4f4fea4133aac1b5)
Target: x86_64-unknown-linux-gnu
Thread model: posix

After some more bit of searching I managed to build for cortex-a with
clang -march=armv7-a -mfloat-abi=soft -ccc-host-triple arm-elf
-integrated-as testReference.cpp -c

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

If anyone can point me to some reading or shine some light on this
one, I'd really appreciate it.

Thanks,
Salvatore

Hi there,

I'm trying to switch from GCC to llvm (clang++) for cross-compiling
a firmware of mine for a stm32 (ARM cortex-m3).

After looking in the documentation and a bit of googling here is what
I did (in case someone else in the future is having the same problem)

cd llvm
git clone http://llvm.org/git/llvm.git

cd llvm/tools
git clone http://llvm.org/git/clang.git

cd llvm/projects
git clone http://llvm.org/git/compiler-rt.git

cd ../llvm-build/
../llvm/configure --prefix=$(HOME)/bin/llvm
--exec-prefix=$(HOME)/bin/llvm  --enable-targets=x86_64,arm,cpp
--enable-optimized

make
make install

It seems everything compiled smoothly, but I can't figure out if there
is any options that list all available targets.
The following only display my host platform as target.

clang -v
clang version 3.2 (http://llvm.org/git/clang.git
88237bf587581026dcfc8386abf055cb201aa487)
(http://llvm.org/git/llvm.git
18a1b616ea123548b61a037c4f4fea4133aac1b5)
Target: x86_64-unknown-linux-gnu
Thread model: posix

After some more bit of searching I managed to build for cortex-a with
clang -march=armv7-a -mfloat-abi=soft -ccc-host-triple arm-elf
-integrated-as testReference.cpp -c

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

If anyone can point me to some reading or shine some light on this
one, I'd really appreciate it.

Thanks,
Salvatore

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/