Is there a tool to convert an edmx into code-first? I know there was talk of one appearing in a CTP a while back, but I can't find any updates relating to this.
There's a guy on the MSDN forums who has written his own (not available yet), but nothing from the EF team.
With EF6 Tools & Visual Studio 2013 or Visual Studio 2012, you get the option code first from database (see screenshot below)
If you don't see this option you need to install Entity Framework 6 Tools for Visual Studio 2012 & 2013 http://www.microsoft.com/en-gb/download/details.aspx?id=40762
This doesn't convert an EDMX to code first (as requested in question), but it can create code first from an existing DB (which I assume someone wanted to do this from EDMX, would have an existing DB, unless they deleted their DB).