Preliminary toggle for core USB

Author: Spegs21

boards.txt

@@ -14,6 +14,8 @@
 # License along with this library; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
+menu.usbstack=Arduino USB Stack
+
 # Arduino Zero (Prorgamming Port)
 # ---------------------------------------
 arduino_zero_edbg.name=Arduino Zero (Programming Port)
@@ -96,6 +98,11 @@ arduino_zero_native.bootloader.tool=openocd
 arduino_zero_native.bootloader.tool.default=openocd
 arduino_zero_native.bootloader.file=zero/samd21_sam_ba.bin
 
+arduino_zero_native.menu.usbstack.enabled=Enabled
+arduino_zero_native.menu.usbstack.enabled.build.flags.usbstack=-DUSBCON
+arduino_zero_native.menu.usbstack.disabled=Disabled
+arduino_zero_native.menu.usbstack.disabled.build.flags.usbstack=-CDC_DISABLED
+
 # Arduino MKR1000
 # -----------------------
 mkr1000.name=Arduino MKR1000

cores/arduino/Arduino.h

@@ -106,11 +106,13 @@ extern void analogOutputInit( void ) ;
 }
 #endif
 
+#if defined(USBCON)
 // USB Device
 #include "USB/USBDesc.h"
 #include "USB/USBCore.h"
 #include "USB/USBAPI.h"
 #include "USB/USB_host.h"
+#endif
 
 // ARM toolchain doesn't provide itoa etc, provide them
 #include "api/itoa.h"

cores/arduino/USB/samd21_host.c

@@ -16,6 +16,7 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
+#ifdef USBCON
 
 #include <stdio.h>
 #include <stdint.h>
@@ -516,3 +517,5 @@ uint32_t UHD_Pipe_Is_Transfer_Complete(uint32_t ul_pipe, uint32_t ul_token_type)
 // }
 
 #endif //  HOST_DEFINED
+
+#endif

cores/arduino/main.cpp

@@ -24,7 +24,9 @@
 void initVariant() __attribute__((weak));
 void initVariant() { }
 
+#if defined(USBCON)
 extern USBDeviceClass USBDevice;
+#endif
 
 // Initialize C library
 extern "C" void __libc_init_array(void);

platform.txt

@@ -77,7 +77,7 @@ compiler.libraries.ldflags=
 
 # USB Flags
 # ---------
-build.usb_flags=-DUSB_VID={build.vid} -DUSB_PID={build.pid} -DUSBCON '-DUSB_MANUFACTURER={build.usb_manufacturer}' '-DUSB_PRODUCT={build.usb_product}'
+build.usb_flags=-DUSB_VID={build.vid} -DUSB_PID={build.pid} '-DUSB_MANUFACTURER={build.usb_manufacturer}' '-DUSB_PRODUCT={build.usb_product}' {build.flags.usbstack}
 
 # Default usb manufacturer will be replaced at compile time using
 # numeric vendor ID if available or by board's specific value.