Add example to the device database file

ld/devices.data

@@ -44,7 +44,23 @@
 # the first will be evaluated, except special group definition "+"
 #
 # The regex matches entire sym
-
+#
+# Example:
+#
+# --- devices.data file ---
+# stm32f05[01]?4* stm32f0 ROM=16K RAM=4K
+# stm32f0 stm32 ROM_OFF=0x08000000 RAM_OFF=0x20000000
+# stm32 END
+#
+# --- queried chip name ---
+# stm32f051c8t6
+#
+# --- output of the awk script ---
+# -DROM=16K -DRAM=4K -DROM_OFF=0x08000000 -DRAM_OFF=0x20000000
+#
+# The generated linker script file will contain sections rom and ram with 
+# appropriate initialization code, specified in linker file source linker.ld.S
+#
 
 ################################################################################
 # the STM32 chips