# Pastebin tcnf1WsA
void board_debug_uart_init(void)
{
	/* Enable early UART on the RK3288 */
	struct rk3288_grf * const grf = (void *)GRF_BASE;

	rk_clrsetreg(&grf->gpio7ch_iomux, GPIO7C7_MASK << GPIO7C7_SHIFT |
		     GPIO7C6_MASK << GPIO7C6_SHIFT,
		     GPIO7C7_UART2DBG_SOUT << GPIO7C7_SHIFT |
		     GPIO7C6_UART2DBG_SIN << GPIO7C6_SHIFT);
}