Question
Why do we need to explicitely set VTOR for dual bank if bank addresses are swapped?
My understanding is that when setting BFB2, Bank 2 is remapped to 0x0800 0000.
Why should we need to set VTOR on reset if thanks to remapping it should interact the same?
Meaning I expect the start of my vector table for app2 to be at the same address as app1 since I have not modified it.
I had to uncomment #define USER_VECT_TAB_ADDRESS so that
SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET;
would run during the SystemInit function at reset.
For context I am compiling two programs with little difference in code and with the same linker script.
/*!< Uncomment the following line if you need to relocate the vector table
anywhere in Flash or Sram, else the vector table is kept at the automatic
remap of boot address selected */
#define USER_VECT_TAB_ADDRESS
#if defined(USER_VECT_TAB_ADDRESS)
/*!< Uncomment the following line if you need to relocate your vector Table
in Sram else user remap will be done in Flash. */
/* #define VECT_TAB_SRAM */
#if defined(VECT_TAB_SRAM)
#define VECT_TAB_BASE_ADDRESS SRAM_BASE /*!< Vector Table base address field.
This value must be a multiple of 0x200. */
#else
#define VECT_TAB_BASE_ADDRESS FLASH_BASE /*!< Vector Table base address field.
This value must be a multiple of 0x200. */
#endif /* VECT_TAB_SRAM */
#if !defined(VECT_TAB_OFFSET)
#define VECT_TAB_OFFSET 0x00000000U /*!< Vector Table offset field.
This value must be a multiple of 0x200. */
void SystemInit(void)
{
/* FPU settings ------------------------------------------------------------*/
#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */
#endif
#if defined (DATA_IN_ExtSRAM) || defined (DATA_IN_ExtSDRAM)
SystemInit_ExtMemCtl();
#endif /* DATA_IN_ExtSRAM || DATA_IN_ExtSDRAM */
/* Configure the Vector Table location -------------------------------------*/
#if defined(USER_VECT_TAB_ADDRESS)
SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
#endif /* USER_VECT_TAB_ADDRESS */
}
Thank you!