synth/arm/app_init.cc

#include <cstdint>

extern "C" int main();
extern uint32_t _bss_begin, _bss_end, _initial_stack_pointer;

__attribute__((section(".app_init"), used)) void AppInit() {
    *(uint32_t*)(0x40000000) = 0;
    asm("mov sp, %0" : : "r"(&_initial_stack_pointer) :);

    // clear .bss
    for (uint32_t* ptr = &_bss_begin; ptr < &_bss_end; ptr++) {
        *ptr = 0;
    }

    main();

    while (true) {
    }
}