startup.c

// Copyright (c) 2022 Cesanta Software Limited
// All rights reserved

// Startup code
__attribute__((naked, noreturn)) void _reset(void) {
  // Initialise memory
  extern long _sbss, _ebss, _sdata, _edata, _sidata;
  for (long *src = &_sbss; src < &_ebss; src++) *src = 0;
  for (long *src = &_sdata, *dst = &_sidata; src < &_edata;) *src++ = *dst++;

  // Call main()
  extern void main(void);
  main();
  for (;;) (void) 0;  // Infinite loop
}

extern void SysTick_Handler(void);  // Defined in main.c
extern void _estack(void);          // Defined in link.ld

// 16 standard and 91 STM32-specific handlers
__attribute__((section(".vectors"))) void (*tab[16 + 91])(void) = {
    _estack, _reset, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, SysTick_Handler};