in port/espressif/src/boot_wdt_port.c [5:11]
void boot_port_wdt_feed( void )
{
wdt_hal_context_t rtc_wdt_ctx = {.inst = WDT_RWDT, .rwdt_dev = &RTCCNTL};
wdt_hal_write_protect_disable(&rtc_wdt_ctx);
wdt_hal_feed(&rtc_wdt_ctx);
wdt_hal_write_protect_enable(&rtc_wdt_ctx);
}