Why I can not call function from address 0x00000000 or 0x08000000?

[sholojda]

I have created a pointer to function like void (*MyFun)(void); and I assigned first time 0x00000000 and the second time 0x08000000. in both cases after call MyFun(); I get HardFault error.

Why?

PS. This is simple project created in CubeIDE (default project for STM32F103) and I only add some lines of code to call MyFun();

[Muhammed Güler]

it represents the start of rom at two addresses. At the start of the rom, there is a vector table in the file called startup_stm32xxxxx.s, where you can see the contents. there is no executable code

[gbm]

Besides the above, the function address for any Cortex-M must be an odd number (real function address with bit 0 set to 1). Generally: do not hardcode any function addresses; use proper type cast when you have to.

[sholojda]

I tried to call this MyFun with address 0x00000001, 0x00000004, 0x08000001, and 0x08000004 and still the same -> HardFault

[Tesla DeLorean]

Is there actually CODE​ there, or ADDRESSES in a vector table?

The.processor can't execute​ addresses!

​

F​or those you'll need to do a 32-bit read and transfer control to that location, rather than the table.

[Muhammed Güler]

0x08000000 has stack end address in it

0x08000004 contains the address of the code to be processed after reset

0x08000008 contains the address of the NMI_Handler function

0x0800000c has the address of HardFault_Handler in it

...

the vector table continues to settle in this way.

These are defined in a file like startup_stm32h753xx.s

In order to work with these addresses, you need to define as pointer to pointer.

[sholojda]

Yes, You're right. I didn't think of it that way. :(

[sholojda]

Can you tell me how to create a pointer to pointer for fuction? Like in this example.

Address 0x08000004 holds address to code execute. How to use it?