Boot Jump Code snippet

BootJumpSTM32.txt

/**
 * Function to perform jump to system memory boot from user application
 * Link: http://www.onarm.com/forum/64128/
 * Call function when you want to jump to system memory
 */
void JumpToBootloader(void) {
	void (*SysMemBootJump)(void);
	
	/**
	 * Step: Set system memory address. 
	 *       
	 *       For STM32F411, system memory is on 0x1FFF 0000
	 *       For other families, check AN2606 document table 110 with descriptions of memory addresses 
	 */
	volatile uint32_t addr = 0x1FFF0000;
	
	/**
	 * Step: Disable RCC, set it to default (after reset) settings
	 *       Internal clock, no PLL, etc.
	 */
	HAL_RCC_DeInit();
	
	/**
	 * Step: Disable systick timer and reset it to default values
	 */
	SysTick->CTRL = 0;
	SysTick->LOAD = 0;
	SysTick->VAL = 0;

	/**
	 * Step: Disable all interrupts
   * Link: http://www.keil.com/support/man/docs/armcc/armcc_chr1359124995648.htm
	 */
	__disable_irq();
	
	/**
	 * Step: Remap system memory to address 0x0000 0000 in address space
	 *       For each family registers may be different. 
	 *       Check reference manual for each family.
	 *
	 *       For STM32F4xx, MEMRMP register in SYSCFG is used (bits[1:0])
	 *       Set and cleared by software. This bit controls the memory internal mapping at
	 *	 address 0x0000 0000. After reset these bits take the value selected by the Boot
  	 *	 pins .
	 *		00: Main Flash memory mapped at 0x0000 0000
	 *		01: System Flash memory mapped at 0x0000 0000
	 *		11: Embedded SRAM mapped at 0x0000 0000
	 */
	SYSCFG->MEMRMP = 0x01;
	//__HAL_SYSCFG_REMAPMEMORY_SYSTEMFLASH();	//Call HAL macro to do this for you
	
	/**
	 * Step: Set jump memory location for system memory
	 *       Use address with 4 bytes offset which specifies jump location where program starts
	 */
	SysMemBootJump = (void (*)(void)) (*((uint32_t *)(addr + 4)));
	
	/**
	 * Step: Set main stack pointer.
	 *       This step must be done last otherwise local variables in this function
	 *       don't have proper value since stack pointer is located on different position
	 *
	 *       Set direct address location which specifies stack pointer in SRAM location
	 */
	__set_MSP(*(uint32_t *)addr);
	
	/**
	 * Step: Actually call our function to jump to set location
	 *       This will start system memory execution
	 */
	SysMemBootJump();
	
	/**
	 * Step: Connect USB<->UART converter to dedicated USART pins and test
	 *       and test with bootloader works with STM32 Flash Loader Demonstrator software
	 */
}