how dose the PC run to startup.s when the mcu reset

Hi,dear enginner:

    i want to know how the PC run to startup.s when mcu reset?

   The Definitive Guide to the ARM Cortex-M3 says address 0x00000000 is MSP‘,address 0x00000004 is ResetVector.

   But when I look at STM32F767, I find that 0x00000000 and 0x4 addresses are other instructions.

   Is there any reference material that can solve my confusion?

 Thanks.

Regards.

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  • Hi there,

    As 42Bastian Schick mentioned the disassembly tools doesn't know that the address 0x0 does not contain instructions and try to disassembly it even if the code doesn't make sense.

    Another thing you need to be aware is that the initial vector table address of Cortex-M7 is not fixed to address 0x0. This is different from Cortex-M3/Cortex-M4. If you want to know the initial vector table address you need to read the VTOR (Vector Table Offset Register) after the processor come out of reset.

    regards,

    Joseph

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