bootloader jump to application address problem

Question

I have written a bootloader for my board, but it generates a hard fault when it jumps to the application code.

My error is like this question:

Bootloader jump to main application problem using STM32 with Keil Uvision

• microcontroller: stm32f103zet
• software: keil
• BOOT pins: BOOT1 and BOOT2 are 0 (FLASH boot mode)
• FLASH_WRITE_ADDRESS: 0x8030000

I did this steps: in application code:

1. I changed ROM address to 0x8030000.
2. I changed VECT_TAB_OFFSET to 0x30000
3. I used of fromelf for creating .bin file

then I wrote a simple code (blinky)

in bootloader code: i receive .bin file with USART and then i write it to address 0x8030000 of FLASH and The following code:

USART_DeInit(USART1);
RCC_DeInit();

__set_CONTROL(ENABLE_PRIVILEGE_MODE);

NVIC->ICER[ 0 ] = 0xFFFFFFFF ;
NVIC->ICER[ 1 ] = 0xFFFFFFFF ;
NVIC->ICER[ 2 ] = 0xFFFFFFFF ;

NVIC->ICPR[ 0 ] = 0xFFFFFFFF ;
NVIC->ICPR[ 1 ] = 0xFFFFFFFF ;
NVIC->ICPR[ 2 ] = 0xFFFFFFFF ;

SysTick->CTRL = 0 ;
SCB->ICSR |= SCB_ICSR_PENDSTCLR_Msk ;

SCB->SHCSR &= ~( SCB_SHCSR_USGFAULTENA_Msk |
                                SCB_SHCSR_BUSFAULTENA_Msk | 
                                SCB_SHCSR_MEMFAULTENA_Msk );

__disable_irq();

if( CONTROL_SPSEL_Msk & __get_CONTROL( ) )
{  /* MSP is not active */
    __set_MSP( __get_PSP( ) ) ;
    __set_CONTROL( __get_CONTROL( ) & ~CONTROL_SPSEL_Msk ) ;
}

JumpAddress=(FLASH_WRITE_ADDRESS+4);
JumpToApplication =(void(*)(void))(*((uint32_t*)JumpAddress));
__set_MSP(*(__IO uint32_t*)FLASH_WRITE_ADDRESS);
JumpToApplication();

But it goes to hardfault. So now I use this part of the code:

/* Jump to user application */
JumpAddress = *(volatile uint32_t*)(FLASH_WRITE_ADDRESS+4);
JumpToApplication = (pFunction) JumpAddress;
__set_MSP((*(volatile uint32_t*) FLASH_WRITE_ADDRESS));
now_pointer=__get_MSP();
JumpToApplication();

but it is the same as before. What is problem?

This is one second before jump to application code:

And this is result of jump to application code:

okey.now,i find and solve problem: i put my writing in FLASH mistake picture:

Answer 1

Most likely you use the standard start-up code from the STM in the user application. Is sets VTOR to the begining of the FLASH memory. Remove this line and it should work

Answer 2

I find my mistake and i solve it.now my bootloader work correctly

but my problem:

1- i I contracted,change vector address line,after main in application file.

2- i commented this lines in bootloader file:

__disable_irq();
__set_MSP((*(volatile uint32_t*) FLASH_WRITE_ADDRESS));

Other than that i had mistake in writting in flash( i not regarding little indian)

and now my code work correctly

thank of all help me to resolve this problem.

Answer 3

As cortex m0+ doesn't have some of the fancy 32bit or even 16bit intermediate and as you will compile to even 1K boundary, You just have to point to new vector table by 8bit left shifted.

  if ( firm1 > firm2) __asm("movs r0, #0x40");       // firmware at 0x4000
  else __asm("movs r0, #0xa0");                      // for firmware at 0xa000
 
   __asm("lsls r0, r0, #8");  
   __asm("ldr  r1, [r0]");  
   __asm("msr  msp, r1");              // Set new MSP 
   __asm("msr  psp, r1");              // PSP based on SP 
   __asm("ldr  r1, [r0,#0x4]");  
   __asm("mov  pc, r1");               // Jump by changing PC