IAP升级准备

思路：.bin文件放置到后背区，然后设置标志位，最后重启。

比如：

#define FLASH_PAGE_SIZE		 0x800	//2048, 2k per page.
#define BOOTLOADER_EXEC_ADDR     0x08000000	// start address of on-chip Flash, bootloader MAX is 32kB
#define APP_EXEC_ADDR	         0x08008000	//address start (integral multiple of 0x200 plus + 0x08000000)
#define APP_MAX_SIZE		 0x30000		// firmware is about 120kB, 160K at max assigned for it
#define APP_BAKUP_ADDR	         (APP_EXEC_ADDR+APP_MAX_SIZE)	
#define NEW_RU_FLAG		 (APP_EXEC_ADDR-0x800)		// 2kB, one Page, writable only after Erased