STM32 Hardfault when trying to access memory

Question

I am analyzing code written for STM32H730 microcontroller. I find the below snippet of code which is giving hardfault when the BootHoldRequest(&fnBoot) is called.

#define BOOTBLOCK_ADD        0x08000000L
#define BootHoldRequest        (*((BOOTLOAD_PROCEED_TYPE *) (BOOTBLOCK_ADD + 0x200)))

typedef void (* CALLBACK_PTR)(void);
typedef uint16_t BOOTLOAD_PROCEED_TYPE(CALLBACK_PTR *);

typedef void (* VOID_FUN_TYPE)(void);
static VOID_FUN_TYPE fnBoot;

if (BootHoldRequest(&fnBoot)) //<--------- HARDFAULT
{
       
}

Answer 1

As it is impossible to answer your question not seeing the whole project (including linker scripts etc) I will only show how to debug this issue.

1. What does this code do?

if (BootHoldRequest(&fnBoot))

        ldr     r0, .L6
        ldr     r3, .L6+4
        bx      r3
.L6:
        .word   .LANCHOR0
        .word   0x8000200

It loads the 4 bytes address from the BOOTBLOCK_ADD + 0x200 location and then next calls code located at this address. I do not know if you have the correct data there so you need to check it yourself.

If you use IDE (in my example Atollic - which is almost identical with STM32Cube IDE) you can easily check it.

Two methods: Set the breakpoint at this line.

1. Use the expression window to see what is at this address:
2. Enter the instruction debug mode

And follow the code one assembly instruction at the time. You will see if the code does what it is supposing to do. It is not your code. It is the code from my project I work on.