[SOLVED] [ASK] jumps to a specific address in STM32 Cortex-M3

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Ahmad Edi Saputra

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[ASK] jump to specific address in STM32 Cortex-M3

Hi

i am currently using stm32f103C8, i want to build a custom bootloader in address 0x8000000 and my application will placed in 0x8008000.
in cortex M4 (stm32f407vgtx) i manage to jump to address 0x8008000 with these code

Code: 
if (((*(__IO uint32_t*)APPLICATION_ADDRESS) & 0x2FFE0000 ) == 0x20000000){
      JumpAddress = *(__IO uint32_t*) (APPLICATION_ADDRESS + 4);
      Jump_To_Application = (pFunction) JumpAddress;
      __set_MSP(*(__IO uint32_t*) APPLICATION_ADDRESS);
      Jump_To_Application();
}

but these code seem doesn't work in cortex M3, i tried a few modification. like bellow, it doesn't work either. i am sure my application already in place. i check address 0x8008000 during debug, my binary app was already there, and yes i compile it with address 0x8008000

Code: 
//JumpAddress = *(__IO uint32_t*) (APPLICATION_ADDRESS + 4);
//Jump_To_Application = (pFunction) JumpAddress;
stackAddress = *(__IO uint32_t*) APPLICATION_ADDRESS;
SCB->VTOR = APPLICATION_ADDRESS;
__set_MSP(stackAddress);
//Jump_To_Application();
NVIC_SystemReset();

Best Regards
Edi
 

Re: [ASK] jump to specific address in STM32 Cortex-M3

Code: 
typedef void (*pFunction)(void);
pFunction Jump_To_Application;
uint32_t JumpAddress;

..........YOUR CODE.............

  NVIC_SetVectorTable(NVIC_VectTab_FLASH, MAIN_FLASH_OFFSET);
	__disable_irq();
  JumpAddress = *(__IO uint32_t*) (MAIN_FLASH_OFFSET + 4);
  Jump_To_Application = (pFunction) JumpAddress;
  __set_MSP(*(__IO uint32_t*) MAIN_FLASH_OFFSET);
  Jump_To_Application();
 

Re: [ASK] jump to specific address in STM32 Cortex-M3

Thanks for your answer


i've tried, but it jump to the next instruction. here is what i meant

Code: 
if (((*(__IO uint32_t*)APPLICATION_ADDRESS) & 0x2FFE0000 ) == 0x20000000){
	NVIC_SetVectorTable(NVIC_VectTab_FLASH, APPLICATION_ADDRESS);
	__disable_irq();
	JumpAddress = *(__IO uint32_t*) (APPLICATION_ADDRESS + 4);
	Jump_To_Application = (pFunction) JumpAddress;
	__set_MSP(*(__IO uint32_t*) APPLICATION_ADDRESS);
	Jump_To_Application();
}
//next instruction

and if i do without calling Jump_To_Application() my bootloader back to main again after all statement in if block is executed. i have no idea why. what do you think?
 

Re: [ASK] jump to specific address in STM32 Cortex-M3

Code: 
*(__IO uint32_t*)APPLICATION_ADDRESS)
is a the value in pointer address, not value of pointer itself. Just your misunderstanding I suppose.
 

Re: [ASK] jump to specific address in STM32 Cortex-M3

i tried to dig deeper, i break down the different hex from STM32f103 and STMF407, bellow is the hex i break down base on intel hex format. i found very interesting fact, that changes of ROM address in keil make no effect for stm32f103 (generated hex is exactly the same), but it has effect on stm32f407. i assume that start address in stm32f407's hex change (0000 and 8000) and i think jump command has also pointed to different location (9D01 and 9D81. i have not found a way to change ROM for stm32f1 yet, any idea?




- - - Updated - - -

Easyrider83 said:
Code: 
*(__IO uint32_t*)APPLICATION_ADDRESS)
is a the value in pointer address, not value of pointer itself. Just your misunderstanding I suppose.
Click to expand...

yah, it is the value from memory address (APPLICATION_ADDRESS or MAIN_FLASH_OFFSET). when i debug, it already has the correct value, if not, it would not be executed at the first time, i mean there is an if to make sure stack pointer has correct offset from 0x20000000

Code: 
if (((*(__IO uint32_t*)APPLICATION_ADDRESS) & 0x2FFE0000 ) == 0x20000000){
//something here
}
 

Re: [ASK] jump to specific address in STM32 Cortex-M3

i think i just figured that out. its definitely linker problem, i change rom base address in the linker option. thanks, i'll mark as resolved
 

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