in port/espressif/src/boot_serial_port.c [194:205]
static void boot_port_serial_write( const char *prt, int cnt )
{
uint32_t space = uart_ll_get_txfifo_len( &UART1 );
if( cnt > space )
{
BOOT_LOG_ERR("Unable to send full message. TX fifo would overflow");
}
/* TODO: Should wait for available space, or continuously chunk */
uart_ll_write_txfifo( &UART1, (const uint8_t *)prt, cnt );
BOOT_LOG_DBG("Response[%d]: %s", cnt, prt);
}