diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/generic/armcm_boot.c | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/src/generic/armcm_boot.c b/src/generic/armcm_boot.c index 5631cb37..8d031c52 100644 --- a/src/generic/armcm_boot.c +++ b/src/generic/armcm_boot.c @@ -18,21 +18,40 @@ extern uint32_t _data_start, _data_end, _data_flash; extern uint32_t _bss_start, _bss_end, _stack_start; extern uint32_t _stack_end; - /**************************************************************** * Basic interrupt handlers ****************************************************************/ -// Initial code entry point - invoked by the processor after a reset -void -ResetHandler(void) +static void __noreturn +reset_handler_stage_two(void) { - // Disable SysTick irq (for some bootloaders that don't) + int i; + + // Clear all enabled user interrupts and user pending interrupts + for (i = 0; i < ARRAY_SIZE(NVIC->ICER); i++) { + NVIC->ICER[i] = 0xFFFFFFFF; + __DSB(); + NVIC->ICPR[i] = 0xFFFFFFFF; + } + + // Reset all user interrupt priorities + for (i = 0; i < ARRAY_SIZE(NVIC->IP); i++) + NVIC->IP[i] = 0; + + // Disable SysTick interrupt SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk; + __DSB(); - // Explicitly load the stack pointer (for some bootloaders that don't) - asm volatile("mov sp, %0" : : "r"(&_stack_end)); - barrier(); + // Clear pending pendsv and systick interrupts + SCB->ICSR = SCB_ICSR_PENDSVCLR_Msk | SCB_ICSR_PENDSTCLR_Msk; + + // Reset all system interrupt priorities + for (i = 0; i < ARRAY_SIZE(SCB->SHP); i++) + SCB->SHP[i] = 0; + + __DSB(); + __ISB(); + __enable_irq(); // Copy global variables from flash to ram uint32_t count = (&_data_end - &_data_start) * 4; @@ -53,6 +72,18 @@ ResetHandler(void) for (;;) ; } + +// Initial code entry point - invoked by the processor after a reset +// Reset interrupts and stack to take control from bootloaders +void +ResetHandler(void) +{ + __disable_irq(); + + // Explicitly load the stack pointer, jump to stage two + asm volatile("mov sp, %0\n bx %1" + : : "r"(&_stack_end), "r"(reset_handler_stage_two)); +} DECL_ARMCM_IRQ(ResetHandler, -15); // Code called for any undefined interrupts |