diff --git a/arch/arm/mach-tegra/tegra124/Kconfig b/arch/arm/mach-tegra/tegra124/Kconfig
index 6fa31ea0a1..fb016aa46c 100644
--- a/arch/arm/mach-tegra/tegra124/Kconfig
+++ b/arch/arm/mach-tegra/tegra124/Kconfig
@@ -19,6 +19,7 @@ config TARGET_JETSON_TK1
 
 config TARGET_CEI_TK1_SOM
 	bool "Colorado Engineering Inc Tegra124 TK1-som board"
+	select ARCH_SUPPORT_PSCI
 	select BOARD_LATE_INIT
 	select CPU_V7_HAS_NONSEC if !SPL_BUILD
 	select CPU_V7_HAS_VIRT if !SPL_BUILD
diff --git a/board/toradex/apalis_t30/pinmux-config-apalis_t30.h b/board/toradex/apalis_t30/pinmux-config-apalis_t30.h
index 49c2df7ab2..3a2cf4606e 100644
--- a/board/toradex/apalis_t30/pinmux-config-apalis_t30.h
+++ b/board/toradex/apalis_t30/pinmux-config-apalis_t30.h
@@ -11,7 +11,9 @@
 		.pingrp		= PMUX_PINGRP_##_pingrp,	\
 		.func		= PMUX_FUNC_##_mux,		\
 		.pull		= PMUX_PULL_##_pull,		\
+/* TRISTATE here means output driver is tri-stated */ \
 		.tristate	= PMUX_TRI_##_tri,		\
+/* INPUT here means input driver is enabled vs. OUTPUT where it is disabled */ \
 		.io		= PMUX_PIN_##_io,		\
 		.lock		= PMUX_PIN_LOCK_DEFAULT,	\
 		.od		= PMUX_PIN_OD_DEFAULT,		\
@@ -118,7 +120,8 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
 	DEFAULT_PINMUX(ULPI_DATA6_PO7, UARTA, NORMAL, NORMAL, INPUT),
 	DEFAULT_PINMUX(ULPI_DATA7_PO0, UARTA, NORMAL, NORMAL, OUTPUT),
 	DEFAULT_PINMUX(ULPI_CLK_PY0, UARTD, NORMAL, NORMAL, OUTPUT),
-	DEFAULT_PINMUX(ULPI_DIR_PY1, UARTD, NORMAL, NORMAL, INPUT),
+	/* UARTD RX, make sure we don't get input form a floating Pin */
+	DEFAULT_PINMUX(ULPI_DIR_PY1, UARTD, UP, NORMAL, INPUT),
 	DEFAULT_PINMUX(ULPI_NXT_PY2, UARTD, NORMAL, NORMAL, INPUT),
 	DEFAULT_PINMUX(ULPI_STP_PY3, UARTD, NORMAL, NORMAL, OUTPUT),
 	DEFAULT_PINMUX(DAP3_FS_PP0, I2S2, NORMAL, NORMAL, INPUT),
@@ -187,12 +190,14 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
 	LV_PINMUX(VI_MCLK_PT1, VI, NORMAL, NORMAL, OUTPUT, DISABLE, DISABLE),
 	LV_PINMUX(VI_PCLK_PT0, VI, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
 	LV_PINMUX(VI_VSYNC_PD6, VI, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
-	DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, NORMAL, NORMAL, INPUT),
+	/* UARTB RX, make sure we don't get input form a floating Pin */
+	DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, UP, NORMAL, INPUT),
 	DEFAULT_PINMUX(UART2_TXD_PC2, UARTB, NORMAL, NORMAL, OUTPUT),
 	DEFAULT_PINMUX(UART2_RTS_N_PJ6, UARTB, DOWN, TRISTATE, OUTPUT), /* NC */
 	DEFAULT_PINMUX(UART2_CTS_N_PJ5, UARTB, DOWN, TRISTATE, OUTPUT), /* NC */
 	DEFAULT_PINMUX(UART3_TXD_PW6, UARTC, NORMAL, NORMAL, OUTPUT),
-	DEFAULT_PINMUX(UART3_RXD_PW7, UARTC, NORMAL, NORMAL, INPUT),
+	/* UARTC RX, make sure we don't get input form a floating Pin */
+	DEFAULT_PINMUX(UART3_RXD_PW7, UARTC, UP, NORMAL, INPUT),
 	DEFAULT_PINMUX(UART3_CTS_N_PA1, UARTC, NORMAL, NORMAL, INPUT),
 	DEFAULT_PINMUX(UART3_RTS_N_PC0, PWM0, NORMAL, NORMAL, OUTPUT),
 	DEFAULT_PINMUX(PU0, RSVD1, DOWN, TRISTATE, OUTPUT),
diff --git a/board/toradex/colibri_t30/colibri_t30.c b/board/toradex/colibri_t30/colibri_t30.c
index c5562f6d57..20cbb75a36 100644
--- a/board/toradex/colibri_t30/colibri_t30.c
+++ b/board/toradex/colibri_t30/colibri_t30.c
@@ -57,6 +57,17 @@ void pinmux_init(void)
 				   ARRAY_SIZE(colibri_t30_padctrl));
 }
 
+/*
+ * Disable RS232 serial transceiver ForceOFF# pins on Iris
+ */
+void gpio_early_init_uart(void)
+{
+	gpio_request(TEGRA_GPIO(X, 6), "Force OFF# X13");
+	gpio_direction_output(TEGRA_GPIO(X, 6), 1);
+	gpio_request(TEGRA_GPIO(X, 7), "Force OFF# X14");
+	gpio_direction_output(TEGRA_GPIO(X, 7), 1);
+}
+
 /*
  * Enable AX88772B USB to LAN controller
  */
diff --git a/board/toradex/colibri_t30/pinmux-config-colibri_t30.h b/board/toradex/colibri_t30/pinmux-config-colibri_t30.h
index bdbbf5e49a..5ac1a6da97 100644
--- a/board/toradex/colibri_t30/pinmux-config-colibri_t30.h
+++ b/board/toradex/colibri_t30/pinmux-config-colibri_t30.h
@@ -11,7 +11,9 @@
 		.pingrp		= PMUX_PINGRP_##_pingrp,	\
 		.func		= PMUX_FUNC_##_mux,		\
 		.pull		= PMUX_PULL_##_pull,		\
+/* TRISTATE here means output driver is tri-stated */ \
 		.tristate	= PMUX_TRI_##_tri,		\
+/* INPUT here means input driver is enabled vs. OUTPUT where it is disabled */ \
 		.io		= PMUX_PIN_##_io,		\
 		.lock		= PMUX_PIN_LOCK_DEFAULT,	\
 		.od		= PMUX_PIN_OD_DEFAULT,		\
@@ -178,14 +180,16 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
 	LV_PINMUX(VI_D7_PL5, SDMMC2, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
 	LV_PINMUX(VI_D10_PT2, RSVD1, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
 	LV_PINMUX(VI_MCLK_PT1, VI, UP, NORMAL, INPUT, DISABLE, DISABLE),
-	DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(UART2_TXD_PC2, UARTB, NORMAL, NORMAL, OUTPUT),
-	DEFAULT_PINMUX(UART2_RTS_N_PJ6, UARTB, NORMAL, NORMAL, OUTPUT),
-	DEFAULT_PINMUX(UART2_CTS_N_PJ5, UARTB, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(UART3_TXD_PW6, UARTC, NORMAL, NORMAL, OUTPUT),
-	DEFAULT_PINMUX(UART3_RXD_PW7, UARTC, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(UART3_CTS_N_PA1, UARTC, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(UART3_RTS_N_PC0, UARTC, NORMAL, NORMAL, OUTPUT),
+	/* UARTC RX, make sure we don't get input form a floating Pin */
+	DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, UP, NORMAL, INPUT),
+	DEFAULT_PINMUX(UART2_TXD_PC2, UARTB, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(UART2_RTS_N_PJ6, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(UART2_CTS_N_PJ5, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(UART3_TXD_PW6, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(UART3_RXD_PW7, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(UART3_CTS_N_PA1, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(UART3_RTS_N_PC0, GMI, NORMAL, NORMAL, INPUT),
+
 	DEFAULT_PINMUX(PU0, RSVD1, NORMAL, NORMAL, INPUT),
 	DEFAULT_PINMUX(PU1, RSVD1, NORMAL, NORMAL, OUTPUT),
 	DEFAULT_PINMUX(PU2, RSVD1, NORMAL, NORMAL, INPUT),
@@ -204,11 +208,11 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
 	DEFAULT_PINMUX(GMI_AD8_PH0, PWM0, NORMAL, NORMAL, OUTPUT), /* LCD1_BL_PWM */
 	DEFAULT_PINMUX(GMI_AD10_PH2, NAND, NORMAL, NORMAL, OUTPUT), /* LCD1_BL_EN */
 	DEFAULT_PINMUX(GMI_A16_PJ7, UARTD, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(GMI_A17_PB0, UARTD, NORMAL, NORMAL, INPUT),
+	/* UARTB RX, make sure we don't get input form a floating Pin */
+	DEFAULT_PINMUX(GMI_A17_PB0, UARTD, UP, NORMAL, INPUT),
 	DEFAULT_PINMUX(GMI_A18_PB1, UARTD, NORMAL, NORMAL, INPUT),
 	DEFAULT_PINMUX(GMI_A19_PK7, UARTD, NORMAL, NORMAL, INPUT),
 
-
 	/* Multiplexed with KB_ROW10/KB_ROW11/KB_ROW12/KB_ROW15 */
 	DEFAULT_PINMUX(CAM_MCLK_PCC0, VI_ALT2, UP, TRISTATE, INPUT),
 	DEFAULT_PINMUX(PCC1, RSVD1, NORMAL, TRISTATE, INPUT),
@@ -268,10 +272,10 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
 	DEFAULT_PINMUX(DAP2_SCLK_PA3, I2S1, NORMAL, NORMAL, INPUT),
 
 	DEFAULT_PINMUX(SPI2_CS1_N_PW2, SPI2, UP, NORMAL, INPUT),
-	DEFAULT_PINMUX(SPI1_MOSI_PX4, SPI1, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(SPI1_SCK_PX5, SPI1, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(SPI1_CS0_N_PX6, SPI1, NORMAL, NORMAL, INPUT),
-	DEFAULT_PINMUX(SPI1_MISO_PX7, SPI1, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(SPI1_MOSI_PX4, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(SPI1_SCK_PX5, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(SPI1_CS0_N_PX6, GMI, NORMAL, NORMAL, INPUT),
+	DEFAULT_PINMUX(SPI1_MISO_PX7, RSVD4, NORMAL, NORMAL, INPUT),
 
 	/* LAN_RESET */
 	DEFAULT_PINMUX(PEX_L0_PRSNT_N_PDD0, RSVD2, NORMAL, NORMAL, OUTPUT),
diff --git a/configs/cei-tk1-som_defconfig b/configs/cei-tk1-som_defconfig
index a1b494ec0f..987e3ac8e9 100644
--- a/configs/cei-tk1-som_defconfig
+++ b/configs/cei-tk1-som_defconfig
@@ -7,6 +7,7 @@ CONFIG_ENV_OFFSET=0xFFFFE000
 CONFIG_SPL_TEXT_BASE=0x80108000
 CONFIG_TEGRA124=y
 CONFIG_TARGET_CEI_TK1_SOM=y
+CONFIG_ARMV7_PSCI_0_1=y
 CONFIG_DEFAULT_DEVICE_TREE="tegra124-cei-tk1-som"
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_CONSOLE_MUX=y
diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h
index ff29ef5a90..82a3a365c5 100644
--- a/include/config_distro_bootcmd.h
+++ b/include/config_distro_bootcmd.h
@@ -118,8 +118,10 @@
 	  "setenv efi_fdtfile ${soc}-${board}${boardver}.dtb; "           \
 	"fi; "
 #else
+#ifndef BOOTENV_EFI_SET_FDTFILE_FALLBACK
 #define BOOTENV_EFI_SET_FDTFILE_FALLBACK
 #endif
+#endif
 
 
 #define BOOTENV_SHARED_EFI                                                \
diff --git a/include/configs/apalis_t30.h b/include/configs/apalis_t30.h
index bf0aefda2a..f0c003d2fe 100644
--- a/include/configs/apalis_t30.h
+++ b/include/configs/apalis_t30.h
@@ -12,7 +12,14 @@
 
 #include "tegra30-common.h"
 
-/* Board-specific serial config */
+/*
+ * Board-specific serial config
+ *
+ * Apalis UART1: NVIDIA UARTA
+ * Apalis UART2: NVIDIA UARTD
+ * Apalis UART3: NVIDIA UARTB
+ * Apalis UART4: NVIDIA UARTC
+ */
 #define CONFIG_TEGRA_ENABLE_UARTA
 #define CONFIG_SYS_NS16550_COM1		NV_PA_APB_UARTA_BASE
 
diff --git a/include/configs/cei-tk1-som.h b/include/configs/cei-tk1-som.h
index dd3bdacc2c..2c406d3186 100644
--- a/include/configs/cei-tk1-som.h
+++ b/include/configs/cei-tk1-som.h
@@ -28,8 +28,6 @@
 #include "tegra-common-usb-gadget.h"
 #include "tegra-common-post.h"
 
-#define CONFIG_ARMV7_PSCI			1
-#define CONFIG_ARMV7_PSCI_NR_CPUS		4
 /* Reserve top 1M for secure RAM */
 #define CONFIG_ARMV7_SECURE_BASE		0xfff00000
 #define CONFIG_ARMV7_SECURE_RESERVE_SIZE	0x00100000
diff --git a/include/configs/colibri_t30.h b/include/configs/colibri_t30.h
index fa0fa93b03..94802a66f7 100644
--- a/include/configs/colibri_t30.h
+++ b/include/configs/colibri_t30.h
@@ -14,7 +14,13 @@
 
 /* High-level configuration options */
 
-/* Board-specific serial config */
+/*
+ * Board-specific serial config
+ *
+ * Colibri UART-A: NVIDIA UARTA
+ * Colibri UART-B: NVIDIA UARTD
+ * Colibri UART-C: NVIDIA UARTB
+ */
 #define CONFIG_TEGRA_ENABLE_UARTA
 #define CONFIG_SYS_NS16550_COM1		NV_PA_APB_UARTA_BASE
 
diff --git a/include/configs/tegra-common.h b/include/configs/tegra-common.h
index 2b968917d3..432eceaf35 100644
--- a/include/configs/tegra-common.h
+++ b/include/configs/tegra-common.h
@@ -49,6 +49,12 @@
 /* Boot Argument Buffer Size */
 #define CONFIG_SYS_BARGSIZE		(CONFIG_SYS_CBSIZE)
 
+#ifdef CONFIG_ARM64
+#define FDTFILE "nvidia/" CONFIG_DEFAULT_DEVICE_TREE ".dtb"
+#else
+#define FDTFILE CONFIG_DEFAULT_DEVICE_TREE ".dtb"
+#endif
+
 /*-----------------------------------------------------------------------
  * Physical Memory Map
  */
diff --git a/include/configs/tegra114-common.h b/include/configs/tegra114-common.h
index d3a7045697..9d751b6740 100644
--- a/include/configs/tegra114-common.h
+++ b/include/configs/tegra114-common.h
@@ -50,6 +50,7 @@
 	"scriptaddr=0x90000000\0" \
 	"pxefile_addr_r=0x90100000\0" \
 	"kernel_addr_r=" __stringify(CONFIG_LOADADDR) "\0" \
+	"fdtfile=" FDTFILE "\0" \
 	"fdt_addr_r=0x83000000\0" \
 	"ramdisk_addr_r=0x83100000\0"
 
diff --git a/include/configs/tegra124-common.h b/include/configs/tegra124-common.h
index 522993b958..0eb8f92809 100644
--- a/include/configs/tegra124-common.h
+++ b/include/configs/tegra124-common.h
@@ -52,6 +52,7 @@
 	"scriptaddr=0x90000000\0" \
 	"pxefile_addr_r=0x90100000\0" \
 	"kernel_addr_r=" __stringify(CONFIG_LOADADDR) "\0" \
+	"fdtfile=" FDTFILE "\0" \
 	"fdt_addr_r=0x83000000\0" \
 	"ramdisk_addr_r=0x83100000\0"
 
diff --git a/include/configs/tegra186-common.h b/include/configs/tegra186-common.h
index b4936cc731..d5f21e0907 100644
--- a/include/configs/tegra186-common.h
+++ b/include/configs/tegra186-common.h
@@ -20,6 +20,12 @@
 /* Generic Interrupt Controller */
 #define CONFIG_GICV2
 
+#undef FDTFILE
+#define BOOTENV_EFI_SET_FDTFILE_FALLBACK                                  \
+        "if test -z \"${fdtfile}\" -a -n \"${soc}\"; then "               \
+          "setenv efi_fdtfile ${vendor}/${soc}-${board}${boardver}.dtb; "           \
+        "fi; "
+
 /*
  * Memory layout for where various images get loaded by boot scripts:
  *
diff --git a/include/configs/tegra20-common.h b/include/configs/tegra20-common.h
index 1e31d82574..fdd8996955 100644
--- a/include/configs/tegra20-common.h
+++ b/include/configs/tegra20-common.h
@@ -51,6 +51,7 @@
 	"scriptaddr=0x10000000\0" \
 	"pxefile_addr_r=0x10100000\0" \
 	"kernel_addr_r=" __stringify(CONFIG_LOADADDR) "\0" \
+	"fdtfile=" FDTFILE "\0" \
 	"fdt_addr_r=0x03000000\0" \
 	"ramdisk_addr_r=0x03100000\0"
 
diff --git a/include/configs/tegra210-common.h b/include/configs/tegra210-common.h
index 1b8e94b60c..2226effe16 100644
--- a/include/configs/tegra210-common.h
+++ b/include/configs/tegra210-common.h
@@ -46,6 +46,7 @@
 	"scriptaddr=0x90000000\0" \
 	"pxefile_addr_r=0x90100000\0" \
 	"kernel_addr_r=" __stringify(CONFIG_LOADADDR) "\0" \
+	"fdtfile=" FDTFILE "\0" \
 	"fdt_addr_r=0x83000000\0" \
 	"ramdisk_addr_r=0x83200000\0"
 
diff --git a/include/configs/tegra30-common.h b/include/configs/tegra30-common.h
index 54bc6756ab..6c5dc24b26 100644
--- a/include/configs/tegra30-common.h
+++ b/include/configs/tegra30-common.h
@@ -47,6 +47,7 @@
 	"scriptaddr=0x90000000\0" \
 	"pxefile_addr_r=0x90100000\0" \
 	"kernel_addr_r=" __stringify(CONFIG_LOADADDR) "\0" \
+	"fdtfile=" FDTFILE "\0" \
 	"fdt_addr_r=0x83000000\0" \
 	"ramdisk_addr_r=0x83100000\0"