ensure g_dfu is linked to start of RAM when building DFU loader

firmware/atmel_softpack_libraries/usb/device/dfu/dfu_driver.c

@@ -35,7 +35,7 @@
 
 /* FIXME: this was used for a special ELF section which then got called
  * by DFU code and Application code, across flash partitions */
-#define __dfudata
+#define __dfudata __attribute__ ((section (".dfudata")))
 #define __dfufunc
 
 /// Standard device driver instance.

firmware/libboard/common/resources/sam3s1/flash.ld

@@ -109,6 +109,8 @@ SECTIONS
     {
         . = ALIGN(4);
         _srelocate = .;
+        /* we must make sure the .dfudata is linked to start of RAM */
+        *(.dfudata .dfudata.*);
         *(.ramfunc .ramfunc.*);
         *(.data .data.*);
         . = ALIGN(4);

firmware/libboard/common/resources/sam3s2/flash.ld

@@ -109,6 +109,8 @@ SECTIONS
     {
         . = ALIGN(4);
         _srelocate = .;
+        /* we must make sure the .dfudata is linked to start of RAM */
+        *(.dfudata .dfudata.*);
         *(.ramfunc .ramfunc.*);
         *(.data .data.*);
         . = ALIGN(4);

firmware/libboard/common/resources/sam3s4/flash.ld

@@ -109,6 +109,8 @@ SECTIONS
     {
         . = ALIGN(4);
         _srelocate = .;
+        /* we must make sure the .dfudata is linked to start of RAM */
+        *(.dfudata .dfudata.*);
         *(.ramfunc .ramfunc.*);
         *(.data .data.*);
         . = ALIGN(4);