diff --git a/arch/arm/mach-rockchip/rk3368/rk3368.c b/arch/arm/mach-rockchip/rk3368/rk3368.c
index 1ed06c5352..f06d27717d 100644
--- a/arch/arm/mach-rockchip/rk3368/rk3368.c
+++ b/arch/arm/mach-rockchip/rk3368/rk3368.c
@@ -124,6 +124,46 @@ void board_debug_uart_init(void)
 		     GPIO2D0_MASK, GPIO2D0_UART0_SIN);
 	rk_clrsetreg(&grf->gpio2d_iomux,
 		     GPIO2D1_MASK, GPIO2D1_UART0_SOUT);
+#elif defined(CONFIG_DEBUG_UART_BASE) && (CONFIG_DEBUG_UART_BASE == 0xff1c0000)
+	struct rk3368_pmu_grf * const pmugrf __maybe_unused =
+		(struct rk3368_pmu_grf * const)0xff738000;
+
+	enum {
+		/* UART4 */
+		GPIO0D2_MASK		= GENMASK(5, 4),
+		GPIO0D2_GPIO		= 0,
+		GPIO0D2_UART4_SOUT	= (3 << 4),
+
+		GPIO0D3_MASK		= GENMASK(7, 6),
+		GPIO0D3_GPIO		= 0,
+		GPIO0D3_UART4_SIN	= (3 << 6),
+	};
+
+	/* Enable early UART4 on the PX5 */
+	rk_clrsetreg(&pmugrf->gpio0d_iomux,
+		     GPIO0D2_MASK | GPIO0D3_MASK,
+		     GPIO0D2_UART4_SOUT | GPIO0D3_UART4_SIN);
+#elif defined(CONFIG_DEBUG_UART_BASE) && (CONFIG_DEBUG_UART_BASE == 0xff690000)
+	struct rk3368_grf * const grf =
+		(struct rk3368_grf * const)0xff770000;
+
+	enum {
+		GPIO2A6_SHIFT           = 12,
+		GPIO2A6_MASK            = GENMASK(13, 12),
+		GPIO2A6_GPIO            = 0,
+		GPIO2A6_UART2_SIN       = (2 << GPIO2A6_SHIFT),
+
+		GPIO2A5_SHIFT           = 10,
+		GPIO2A5_MASK            = GENMASK(11, 10),
+		GPIO2A5_GPIO            = 0,
+		GPIO2A5_UART2_SOUT      = (2 << GPIO2A5_SHIFT),
+	};
+
+	/* Enable early UART2 on the RK3368 */
+	rk_clrsetreg(&grf->gpio2a_iomux,
+		     GPIO2A6_MASK, GPIO2A6_UART2_SIN);
+	rk_clrsetreg(&grf->gpio2a_iomux,
+		     GPIO2A5_MASK, GPIO2A5_UART2_SOUT);
 #endif
 }
 #endif