title: Build armeabi instead of armeabi-v7a target using arm clang toolchain
body: <p>I followed the article "Standalone Toolchains" to create seven customized toolchains (armeabi, armeabi-v7a, arm64-v8a, misp, mips64, x86, and x86_64). Then I want to build PROJ.4 library. I know ARM clang toolchain by default targets armeabi-v7a, so in order to target armeabi, I use the following commands:</p>
  
  <pre><code>export CFLAGS="-march=arm -O2"
  export CC=~/Android/toolchain/arm/bin/clang
  export CXX==~/Android/toolchain/arm/bin/clang++
  ./configure --host=arm-linux-androideabi
  </code></pre>
  
  <p>Then I get the errors:
  clang38: error: the clang compiler does not support '-march=arm'</p>
  
  <p>If I change CFLAGS to "-march=arm-v7a -O2", there would be no errors. But it targets armeabi-v7a, not armeabi. So what is the value for -march flag targeting armeabi?</p>