Updated Micro Python on Mac OSX (markdown)

Micro-Python-on-Mac-OSX.md

@@ -19,9 +19,11 @@ In order to compile on OSX you will need the following software packages install
 * If you like using git completion or `$(__git_ps1)` for your prompt, then add the following line to your ~/.bashrc file: `. /opt/local/share/git/contrib/completion/git-prompt.sh`
 
 ## Build Process
-Same as on Linux - go to `micropython/ports/unix` and 
-- run `make axtls`,
-- run `make` (or `make -B` or `make clean; make` if rebuilding.
+Same as on Linux 
+- go to `micropython/mpy-cross`and run `make -C mpy-cross``
+- go to `micropython/ports/unix` and 
+   - run `make axtls`,
+   - run `make` (or `make -B` or `make clean; make` if rebuilding.
 
 If installing libffi with homebrew, you might have to specify its location to pkgconfig
 ```