How to generate assembly code from C++ source in Visual Studio 2010

I believe this is what the /FA switch is for.

in http://msdn.microsoft.com/en-us/library/367y26c6.aspx

You can use "/FA /Fa" options you can use..

In there documents,

CL /FAcs HELLO.CPP

/FA    Assembly code; .asm
/FAc   Machine and assembly code; .cod
/FAs   Source and assembly code; .asm
       If /FAcs is specified, the file extension will be .cod
/FAu   Causes the output file to be created in UTF-8 format, 
       with a byte order marker. 
       By default, the file encoding is ANSI, 
       but use /FAu if you want a listing file that displays correctly on any system, 
       or if you are using Unicode source code files as input to the compiler.
       If /FAsu is specified, and if a source code file uses Unicode encoding other than UTF-8, 
       then the code lines in the .asm file may not display correctly.