The CY4640 is very easy to customize and change the functionality. The reason behind this is that not every customer will want to have all of the available options. For example you might want to have an internal HDD where a different customer has no need for this. To make the modification all you need to do is edit the fwxcfg.h file found in the source directory. In this file the various options have either #define or #undef in front of them. If it is defined with a #define then that functionality will be compiled into the code. If it uses a #undef then it will not be compiled in. After the modifications are done simply rebuild the project with the make command. Note how the amount of used memory changes when this is done.