Jump to Bootlader issue

[izobonito]

Hi to all,

First of all, I apoligize for new topic about bootloader. I have searched but haven't found any post about it.

I'm working about custom bootloader via uart for STM32F072 microprocessor. I analyzed example of Usb Uart Bootloader project and i have tried same method for jump to bootloader firmware unlike jump to application but did't work.

My question is, how can i jump to bootloader start address(0x0801FC00). How can i set main stack pointer and call reset handler? Can anyone explain or send sample codes?

Best regards,

[stefan.filipovic]

Hi,

Welcome to the MikroE forum.

You didn't specify which MCU from the STM32F072 family you are using.

If it's STM32F072CB which has ROM range 00000000-0001FFFF, you need to set constants in the following example as below: C:\Users\Public\Documents\Mikroelektronika\mikroC PRO for ARM\Examples\ST\Other\USB UART Bootloader\STM32F051R8

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#pragma orgall 0x1EC00
#define BOOTLOADER_START_ADDR   0x1EC00
#define START_PROGRAM_ADDR      0x1FC00

You use directive org to specify a starting address of a routine in ROM.

Kind regards,

[izobonito]

Hi,

Thanks for your reply. I realized that should to give more info about my project..

I'm using a STM32F072CB. My application has very big size that is almost 110k. Bootloader size is almost 12k.

Application starts 0x0000000 and bootloader starts 0x0801C000 address. They are working succesfully.

Bootloader firmware has been tried before same mcu(STM32F072CB) and it's working succesfully. I think that important thing is application and bootloader were KEIL projects. But now, Application project is on Microbasic Pro Arm IDE and Bootloader project is on KEIL IDE.

I used to this pieces of codes to jump to bootloader in KEIL project.

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	#define   BOOTLOADER_ADDRESS 0x0801C000

	if (((*(__IO uint32_t*)BOOTLOADER_ADDRESS) & 0x2FFE0000 ) == 0x20000000)
	{ 
		JumpAddress = *(__IO uint32_t*) (BOOTLOADER_ADDRESS+ 4);
		JumpToBootloader = (pFunction) JumpAddress;
		
		/* Initialize user application's Stack Pointer */
		__set_MSP(*(__IO uint32_t*) BOOTLOADER_ADDRESS);
		
		JumpToBootloader();
	}

Like above code, i think that i need to similar codes on Microbasic. I have tried pieces of code below that you said "C:\Users\Public\Documents\Mikroelektronika\mikroC PRO for ARM\Examples\ST\Other\USB UART Bootloader\STM32F051R8"

Code: Select all

const START_BOOTLOADER_ADDR      = 0x0801F000

sub procedure Start_Bootloader() org 0x1F000 

end sub

sub procedure Write_Begin()
    dim i as word
    ptr as ^longword
    value as longword
    appResetVector as byte[16]
    arm_m0_inst as longword
    dataToWrite as word

  ptr = 0x0801C000
  
  FLASH_Unlock()
    
  'LDR R0, PC+X
  arm_m0_inst = 0x4800 + 1

  appResetVector[0] = arm_m0_inst
  appResetVector[1] = arm_m0_inst >> 8

  'MOV SP, R0
  arm_m0_inst = 0x4685

  appResetVector[2] = arm_m0_inst
  appResetVector[3] = arm_m0_inst >> 8

  'LDR R0, PC+Y
  arm_m0_inst = 0x4800 + 1

  appResetVector[4] = arm_m0_inst
  appResetVector[5] = arm_m0_inst >> 8

  'BX R0
  arm_m0_inst = 0x4700
  appResetVector[6] = arm_m0_inst
  appResetVector[7] = arm_m0_inst >> 8


  value = ptr^

  'SP
  appResetVector[8]  = value
  appResetVector[9]  = value >> 8
  appResetVector[10] = value >> 16
  appResetVector[11] = value >> 24

  ptr = 0x0801C004
  value = ptr^
  
  'PC
  appResetVector[12] = value
  appResetVector[13] = value >> 8
  appResetVector[14] = value >> 16
  appResetVector[15] = value >> 24

  FLASH_ErasePage(START_BOOTLOADER_ADDR)

  for i = 0 to 7
    dataToWrite = appResetVector[i * 2] or (appResetVector[i * 2 + 1] << 8)
    FLASH_Write_HalfWord( START_BOOTLOADER_ADDR + i*2, dataToWrite)
  next i

  FLASH_Lock()
  
end sub

When i get special character via uart to jump to bootloader, i call below function. But it's not jumping to 0x0801C000 address.

Code: Select all

sub procedure jumpToBootloader
	Write_Begin()
	Start_Bootloader()
end sub

I hope its more clear and understandable.

Best regars,

[stefan.filipovic]

Hi,

In that case, you should set the bootloader start address to 0x1C000 instead of 0x1F000:

Code: Select all

const START_BOOTLOADER_ADDR      = 0x0801C000

sub procedure Start_Bootloader() org 0x1C000 

end sub

Kind regards,