Fixed bug #504.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@6939 35acf78f-673a-0410-8e92-d51de3d6d3f4
Fixed various errors.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@6940 35acf78f-673a-0410-8e92-d51de3d6d3f4