The problem is not the cross-compiling here but the debugging part. You can edit and build your ARM project by using CB with an appropriate compiler (if there exits any). But for the debugging, to connect a board of your choice there must be a 'gdb-server' to establish communications between the 'gdb' and the board itself, like 'avarice' for the AVR target for example. That's not in anyway related to CB. So to debug your microcontroller, first you have to program your compiled code into the mcu (tools menu is useful here to define shortcuts for command line programmer software) then launch the corresponding 'gdb-server' for your mcu and connect to it again with the corresponding 'gdb' for your mcu. That's basically how it works.