nodemcu-firmware/app/user/user_exceptions.h

#include "sections.h"
#include "rom.h"
#include <xtensa/corebits.h>

void load_non_32_wide_handler (struct exception_frame *ef, uint32_t cause) TEXT_SECTION_ATTR;
void __real__xtos_set_exception_handler (uint32_t cause, exception_handler_fn fn);