New bootrom

+ Add common area at end of RAM to communicate between main os and bootrom
+ Lower stack end to make room for common area
+ Implement CMD_DEVICE_INFO in both OS and bootrom to give information about the current state and supported features
+ Allow hands-free firmware update: When CMD_START_FLASH is received over USB in OS mode, the device will reset and enter the bootrom
  Pressing the button in hands-free update mode takes precedence: releasing the button will immediately abort firmware update and 
  perform a reset. Do not press the button.
+ Require each flash sequence to be preceded by a CMD_START_FLASH to set up the boundaries for the following flash sequence
  Not compatible with linux flasher before SVN revision 200
  Currently no compatible flasher for Windows. WINDOWS USERS: DO NOT UPDATE YOUR BOOTROM YET
+ Protect bootrom flash area unless magic unlock sequence is given in CMD_START_FLASH

include/proxmark3.h

@@ -70,4 +70,18 @@ struct version_information {
 	char buildtime[30]; /* string with the build time */
 } __attribute__((packed));
 
+#define COMMON_AREA_MAGIC 0x43334d50
+#define COMMON_AREA_COMMAND_NONE 0
+#define COMMON_AREA_COMMAND_ENTER_FLASH_MODE 1
+struct common_area {
+	int magic; /* Magic sequence, to distinguish against random uninitialized memory */
+	char version; /* Must be 1 */
+	char command;
+	struct {
+		unsigned int bootrom_present:1; /* Set when a bootrom that is capable of parsing the common area is present */
+		unsigned int osimage_present:1; /* Set when a osimage that is capable of parsing the common area is present */
+	} __attribute__((packed)) flags;
+	int arg1, arg2;
+} __attribute__((packed));
+
 #endif