mainboard/lenovo/t430s: Add ThinkPad T431s as a variant

The code is based on autoport and that for T430s

Tested:
- CPU i5-3337U
- Slotted DIMM 2GiB
- Soldered RAM 4GiB from samsung (There may be more models here)
- Camera
- pci-e and usb2 on M.2 slot with A key for wlan
- sata and usb2  (no superspeed components) on M.2 slot with B key for wwan
- On board SDHCI connected to pci-e
- USB3 ports
- libgfxinit-based graphic init
- NVRAM options for North and South bridges
- Sound
- Thinkpad EC
- S3
- TPM1 on LPC
- EHCI debug on SSP2 (USB3 port on the left)
- Linux 4.9.110-3 within Debian GNU/Linux stable, loaded from
  Linux payload (Heads), Seabios may also work.

Not tested:
- Fingerprint reader on USB2 (not present on mine)
- Keyboard backlight (not present on mine)
- "sticky_fn" flag in nvram

Not implemented yet:
- Fn locking in nvram (may not be identical to "sticky_fn")
- C-based native graphic init (since T431s has eDP instead of LVDS)
- Detecting the model of Soldered RAM at runtime, and loading the
  corresponding SPD datum (3 observed) from CBFS (the mechanism may be
  similar to that on x1_carbon_gen1 and s230u, but I do not know how
  to find gpio ports for that, and SPD data stored in vendor firmware.)

Change-Id: Ic8062cacf5e8232405bb5757e1b1d063541f354a
Signed-off-by: Bill XIE <persmule@gmail.com>
Reviewed-on: https://review.coreboot.org/c/30021
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/Documentation/mainboard/index.md b/Documentation/mainboard/index.md
index 128f0c1..356f203 100644
--- a/Documentation/mainboard/index.md
+++ b/Documentation/mainboard/index.md
@@ -60,6 +60,7 @@
 - [T530](lenovo/w530.md)
 - [W530](lenovo/w530.md)
 - [T430 / T530 / X230 / W530 common](lenovo/xx30_series.md)
+- [T431s](lenovo/t431s.md)
 
 ## SiFive
 
diff --git a/Documentation/mainboard/lenovo/t431s.md b/Documentation/mainboard/lenovo/t431s.md
new file mode 100644
index 0000000..146e1c12
--- /dev/null
+++ b/Documentation/mainboard/lenovo/t431s.md
@@ -0,0 +1,42 @@
+# Lenovo T431s
+
+## Disassembly Instructions
+
+You must remove the following parts before flipping the mainboard
+off the main frame:
+
+![t431s_bc_removed](t431s_bc_removed.jpg)
+
+* Base cover
+* Hard disk drive
+* Battery pack
+* Keyboard
+
+Its [Hardware Maintenance Manual](https://thinkpads.com/support/hmm/hmm_pdf/t431s_hmm_en_0c10894_02.pdf) could be used as a guidance of disassembly.
+
+![t431s_flash_chip](t431s_flash_chip.jpg)
+
+The WSON-8 flash chip (surrounded with red circle in the photo above)
+sits on the opposite side of the mainboard, under a piece of insulating
+tape. If solders between the chip and soldering pads fortunately
+overflows beside the chip as tiny tin balls attached to soldering pads,
+it will be possible to use a pomona 5250 clip to hold the chip, with
+its metal tips just attached to tin balls, thus connecting the chip to
+the programmer.
+
+![t431s_programming](t431s_programming.jpg)
+
+```eval_rst
+:doc:`../../flash_tutorial/ext_power`
+```
+
+Currently, detecting the model of soldered RAM at runtime and loading
+the corresponding SPD datum from CBFS is not implemented yet. You may
+have to dump the SPD data when running the vendor firmware with
+inteltool, and replace the content of the SPD hex with what is dumped.
+
+(the mechanism may be similar to that on x1_carbon_gen1 and s230u, but
+I do not know how to find gpio ports for that, and SPD data stored in
+vendor firmware.)
+
+[T420 / T520 / X220 / T420s / W520 common]: xx20_series.md
diff --git a/Documentation/mainboard/lenovo/t431s_bc_removed.jpg b/Documentation/mainboard/lenovo/t431s_bc_removed.jpg
new file mode 100644
index 0000000..4f8ddd6
--- /dev/null
+++ b/Documentation/mainboard/lenovo/t431s_bc_removed.jpg
Binary files differ
diff --git a/Documentation/mainboard/lenovo/t431s_flash_chip.jpg b/Documentation/mainboard/lenovo/t431s_flash_chip.jpg
new file mode 100644
index 0000000..48c861e
--- /dev/null
+++ b/Documentation/mainboard/lenovo/t431s_flash_chip.jpg
Binary files differ
diff --git a/Documentation/mainboard/lenovo/t431s_programming.jpg b/Documentation/mainboard/lenovo/t431s_programming.jpg
new file mode 100644
index 0000000..c49562a
--- /dev/null
+++ b/Documentation/mainboard/lenovo/t431s_programming.jpg
Binary files differ
diff --git a/src/mainboard/lenovo/t430s/Kconfig b/src/mainboard/lenovo/t430s/Kconfig
index f6096d8..e507ec8 100644
--- a/src/mainboard/lenovo/t430s/Kconfig
+++ b/src/mainboard/lenovo/t430s/Kconfig
@@ -1,4 +1,4 @@
-if BOARD_LENOVO_T430S
+if BOARD_LENOVO_T430S || BOARD_LENOVO_T431S
 
 config BOARD_SPECIFIC_OPTIONS
 	def_bool y
@@ -16,12 +16,12 @@
 	select HAVE_CMOS_DEFAULT
 	select HAVE_ACPI_RESUME
 	select INTEL_INT15
-	select SANDYBRIDGE_IVYBRIDGE_LVDS
+	select SANDYBRIDGE_IVYBRIDGE_LVDS if BOARD_LENOVO_T430S
 	select ENABLE_VMX
 	select MAINBOARD_HAS_LPC_TPM
 	select MAINBOARD_HAS_TPM1
 	select MAINBOARD_HAS_LIBGFXINIT
-	select GFX_GMA_INTERNAL_IS_LVDS
+	select GFX_GMA_INTERNAL_IS_LVDS if BOARD_LENOVO_T430S
 	select INTEL_GMA_HAVE_VBT
 
 	# Workaround for EC/KBC IRQ1.
@@ -31,9 +31,19 @@
 	string
 	default lenovo/t430s
 
+config VARIANT_DIR
+	string
+	default "t430s" if BOARD_LENOVO_T430S
+	default "t431s" if BOARD_LENOVO_T431S
+
 config MAINBOARD_PART_NUMBER
 	string
-	default "ThinkPad T430s"
+	default "ThinkPad T430s" if BOARD_LENOVO_T430S
+	default "ThinkPad T431s" if BOARD_LENOVO_T431S
+
+config OVERRIDE_DEVICETREE
+	string
+	default "variants/$(CONFIG_VARIANT_DIR)/overridetree.cb"
 
 config MAX_CPUS
 	int
@@ -57,10 +67,11 @@
 
 config MAINBOARD_PCI_SUBSYSTEM_DEVICE_ID
 	hex
-	default 0x21fb
+	default 0x21fb if BOARD_LENOVO_T430S
+	default 0x2208 if BOARD_LENOVO_T431S
 
 config ONBOARD_VGA_IS_PRIMARY
 	bool
 	default y
 
-endif # BOARD_LENOVO_T430S
+endif # BOARD_LENOVO_T430S || BOARD_LENOVO_T431S
diff --git a/src/mainboard/lenovo/t430s/Kconfig.name b/src/mainboard/lenovo/t430s/Kconfig.name
index f940249..85916b9 100644
--- a/src/mainboard/lenovo/t430s/Kconfig.name
+++ b/src/mainboard/lenovo/t430s/Kconfig.name
@@ -1,2 +1,5 @@
 config BOARD_LENOVO_T430S
 	bool "ThinkPad T430s"
+
+config BOARD_LENOVO_T431S
+	bool "ThinkPad T431s"
diff --git a/src/mainboard/lenovo/t430s/Makefile.inc b/src/mainboard/lenovo/t430s/Makefile.inc
index cb01f1c..d70c22e 100644
--- a/src/mainboard/lenovo/t430s/Makefile.inc
+++ b/src/mainboard/lenovo/t430s/Makefile.inc
@@ -14,5 +14,8 @@
 ##
 
 smm-$(CONFIG_HAVE_SMI_HANDLER) += smihandler.c
-romstage-y += gpio.c
+romstage-y += variants/$(VARIANT_DIR)/gpio.c
+romstage-y += variants/$(VARIANT_DIR)/romstage.c
+ramstage-y += variants/$(VARIANT_DIR)/hda_verb.c
 ramstage-$(CONFIG_MAINBOARD_USE_LIBGFXINIT) += gma-mainboard.ads
+subdirs-$(CONFIG_BOARD_LENOVO_T431S) += variants/$(VARIANT_DIR)/spd
diff --git a/src/mainboard/lenovo/t430s/board_info.txt b/src/mainboard/lenovo/t430s/board_info.txt
index 9dc9e19..703bf48 100644
--- a/src/mainboard/lenovo/t430s/board_info.txt
+++ b/src/mainboard/lenovo/t430s/board_info.txt
@@ -1,4 +1,5 @@
 Category: laptop
+Board name: ThinkPad T430s baseboard
 ROM package: SOIC-8 / WSON-8
 ROM protocol: SPI
 ROM socketed: n
diff --git a/src/mainboard/lenovo/t430s/devicetree.cb b/src/mainboard/lenovo/t430s/devicetree.cb
index b14d60c..56e7f63 100644
--- a/src/mainboard/lenovo/t430s/devicetree.cb
+++ b/src/mainboard/lenovo/t430s/devicetree.cb
@@ -65,8 +65,8 @@
 			register "gen4_dec" = "0x0c06a1"
 
 			register "pcie_hotplug_map" = "{ 0, 0, 1, 0, 0, 0, 0, 0 }"
-
-			register "xhci_switchable_ports" = "0xf"
+			# Wire port 4 (wwan usb) to ehci for it lacks superspeed components
+			register "xhci_switchable_ports" = "0x7"
 			register "superspeed_capable_ports" = "0xf"
 			register "xhci_overcurrent_mapping" = "0x4000201"
 
@@ -74,6 +74,7 @@
 			register "pcie_port_coalesce" = "1"
 			register "c2_latency" = "101"  # c2 not supported
 			register "p_cnt_throttling_supported" = "1"
+			register "docking_supported" = "1"
 
 			register "spi_uvscc" = "0x2005"
 			register "spi_lvscc" = "0x2005"
@@ -154,10 +155,6 @@
 					register "eventc_enable" = "0xff"
 					register "eventd_enable" = "0xff"
 					register "evente_enable" = "0x0d"
-
-					register "has_bdc_detection" = "1"
-					register "bdc_gpio_num" = "54"
-					register "bdc_gpio_lvl" = "0"
 				end
 			end # LPC Controller
 			device pci 1f.2 on
diff --git a/src/mainboard/lenovo/t430s/hda_verb.c b/src/mainboard/lenovo/t430s/hda_verb.c
index ee54874..2997587 100644
--- a/src/mainboard/lenovo/t430s/hda_verb.c
+++ b/src/mainboard/lenovo/t430s/hda_verb.c
@@ -1,127 +1 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
- * Copyright (C) 2014 Vladimir Serbinenko
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-/*	Vendor Name    : Realtek
- *	Vendor ID      : 0x10ec0269
- *	Subsystem ID   : 0x17aa21fb
- *	Revision ID    : 0x100203
- */
-
-
-#include <device/azalia_device.h>
-
-const u32 cim_verb_data[] = {
-	/* coreboot specific header */
-	0x10ec0269,	// Codec Vendor / Device ID: Realtek ALC269VC
-	0x17aa21fb,	// Subsystem ID
-	0x00000013,	// Number of 4 dword sets
-
-/* Bits 31:28 - Codec Address */
-/* Bits 27:20 - NID */
-/* Bits 19:8 - Verb ID */
-/* Bits 7:0  - Payload */
-
-/* NID 0x01 - NodeInfo */
-	AZALIA_SUBVENDOR(0x0, 0x17AA21FB),
-
-/* NID 0x0A - External Microphone Connector
- * Config=0x04A11020 (External,Right; MicIn,3.5mm; Black,JD; DA,Seq)
- */
-	AZALIA_PIN_CFG(0x0, 0x0A, 0x04A11020),
-
-/* NID 0x0B - Headphone Connector
- * Config=0x0421101F (External,Right; HP,3.5mm; Black,JD; DA,Seq)
- */
-	AZALIA_PIN_CFG(0x0, 0x0B, 0x0421101F),
-
-/* NID 0x0C - Not connected
- * Config=0x40F000F0 (N/A,N/A; Other,Unknown; Unknown,JD; DA,Seq)
- */
-	AZALIA_PIN_CFG(0x0, 0x0C, 0x40F000F0),
-
-/* NID 0x0D - Internal Speakers
- * Config=0x90170110 (Fixed,Int; Speaker,Other Analog; Unknown,nJD; DA,Seq)
- */
-	AZALIA_PIN_CFG(0x0, 0x0D, 0x90170110),
-
-/* NID 0x0F - Not connected
- * Config=0x40F000F0
- */
-	AZALIA_PIN_CFG(0x0, 0x0F, 0x40F000F0),
-
-/* NID 0x11 - Internal Microphone
- * Config=0xD5A30140 (Fixed internal,Top; Mic In,ATIPI; Unknown,nJD; DA,Seq)
- */
-	AZALIA_PIN_CFG(0x0, 0x12, 0x90A60140),
-	AZALIA_PIN_CFG(0x0, 0x14, 0x90170110),
-	AZALIA_PIN_CFG(0x0, 0x15, 0x03211020),
-	AZALIA_PIN_CFG(0x0, 0x17, 0x411111F0),
-	AZALIA_PIN_CFG(0x0, 0x18, 0x03A11830),
-	AZALIA_PIN_CFG(0x0, 0x19, 0x411111F0),
-
-	0x01970804,
-	0x01870803,
-	0x01470740,
-	0x00970600,
-
-	AZALIA_PIN_CFG(0x0, 0x1A, 0x411111F0),
-	AZALIA_PIN_CFG(0x0, 0x1B, 0x411111F0),
-	AZALIA_PIN_CFG(0x0, 0x1D, 0x40138205),
-	AZALIA_PIN_CFG(0x0, 0x1E, 0x411111F0),
-
-	/* Misc entries */
-	0x00370600,
-	0x00270600,
-	0x00B707C0, /* Enable PortB as Output with HP amp */
-	0x00D70740, /* Enable PortD as Output */
-	0x0017A200, /* Disable ClkEn of PortSenseTst */
-	0x0017C621, /* Slave Port - Port A used as microphone input for
-	                            combo Jack
-	               Master Port - Port B used for Jack Presence Detect
-	               Enable Combo Jack Detection */
-	0x0017A208, /* Enable ClkEn of PortSenseTst */
-	0x00170500, /* Set power state to D0 */
-
-	/* --- Next Codec --- */
-
-/*	Vendor Name    : Intel
- *	Vendor ID      : 0x80862806
- *	Subsystem ID   : 0x80860101
- *	Revision ID    : 0x100000
- */
-	/* coreboot specific header */
-	0x80862806,	// Codec Vendor / Device ID: Intel PantherPoint HDMI
-	0x80860101,	// Subsystem ID
-	0x00000004,	// Number of IDs
-
-	/* NID 0x01, HDA Codec Subsystem ID Verb Table: 0x80860101 */
-	AZALIA_SUBVENDOR(0x3, 0x80860101),
-
-	/* Pin Complex (NID 0x05) Digital Out at Int HDMI */
-	AZALIA_PIN_CFG(0x3, 0x05, 0x18560010),
-
-	/* Pin Complex (NID 0x06) Digital Out at Int HDMI */
-	AZALIA_PIN_CFG(0x3, 0x06, 0x18560020),
-
-	/* Pin Complex (NID 0x07) Digital Out at Int HDMI */
-	AZALIA_PIN_CFG(0x3, 0x07, 0x18560030)
-};
-
-const u32 pc_beep_verbs[] = {
-	0x02177a00, /* Digital PCBEEP Gain: 0h=-9db, 1h=-6db ... 4h=+3db, 5h=+6db */
-};
-
-AZALIA_ARRAY_SIZES;
+/* dummy */
diff --git a/src/mainboard/lenovo/t430s/romstage.c b/src/mainboard/lenovo/t430s/romstage.c
index cf7b3e8..ab2bb0a 100644
--- a/src/mainboard/lenovo/t430s/romstage.c
+++ b/src/mainboard/lenovo/t430s/romstage.c
@@ -15,13 +15,8 @@
  * GNU General Public License for more details.
  */
 
-#include <option.h>
-#include <arch/byteorder.h>
-#include <arch/io.h>
-#include <device/pci_def.h>
-#include <northbridge/intel/sandybridge/raminit_native.h>
+#include <northbridge/intel/sandybridge/sandybridge.h>
 #include <southbridge/intel/bd82x6x/pch.h>
-#include <ec/lenovo/pmh7/pmh7.h>
 
 void pch_enable_lpc(void)
 {
@@ -41,47 +36,6 @@
 {
 }
 
-const struct southbridge_usb_port mainboard_usb_ports[] = {
-	{ 1, 0,  0 }, /* P0:, OC 0 */
-	{ 1, 1,  1 }, /* P1: (EHCI debug), OC 1 */
-	{ 1, 1,  3 }, /* P2:  OC 3 */
-	{ 1, 0, -1 }, /* P3: no OC */
-	{ 1, 2, -1 }, /* P4: no OC */
-	{ 1, 1, -1 }, /* P5: no OC */
-	{ 1, 1, -1 }, /* P6: no OC */
-	{ 0, 1, -1 }, /* P7: empty, no OC */
-	{ 1, 1, -1 }, /* P8: smart card reader, no OC */
-	{ 1, 0,  5 }, /* P9:  (EHCI debug), OC 5 */
-	{ 1, 0, -1 }, /* P10: fingerprint reader, no OC */
-	{ 1, 1, -1 }, /* P11: bluetooth, no OC. */
-	{ 0, 0, -1 }, /* P12: wlan, no OC */
-	{ 1, 1, -1 }, /* P13: camera, no OC */
-};
-
-void mainboard_get_spd(spd_raw_data *spd, bool id_only) {
-	read_spd(&spd[0], 0x50, id_only);
-	read_spd(&spd[2], 0x51, id_only);
-}
-
-void mainboard_early_init(int s3resume) {
-	u8 enable_peg;
-	if (get_option(&enable_peg, "enable_dual_graphics") != CB_SUCCESS)
-		enable_peg = 0;
-
-	bool power_en = pmh7_dgpu_power_state();
-
-	if (enable_peg != power_en)
-		pmh7_dgpu_power_enable(!power_en);
-
-	if (!enable_peg) {
-		// Hide disabled dGPU device
-		u32 reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
-		reg32 &= ~DEVEN_PEG10;
-
-		pci_write_config32(PCI_DEV(0, 0, 0), DEVEN, reg32);
-	}
-}
-
 void mainboard_config_superio(void)
 {
 }
diff --git a/src/mainboard/lenovo/t430s/smihandler.c b/src/mainboard/lenovo/t430s/smihandler.c
index 8831e9d..d69f6b6 100644
--- a/src/mainboard/lenovo/t430s/smihandler.c
+++ b/src/mainboard/lenovo/t430s/smihandler.c
@@ -28,17 +28,17 @@
 
 static void mainboard_smi_brightness_up(void)
 {
-	u8 value;
+	u8 value = pci_read_config8(PCI_DEV(0, 2, 1), 0xf4);
 
-	if ((value = pci_read_config8(PCI_DEV(0, 2, 1), 0xf4)) < 0xf0)
+	if (value < 0xf0)
 		pci_write_config8(PCI_DEV(0, 2, 1), 0xf4, (value + 0x10) | 0xf);
 }
 
 static void mainboard_smi_brightness_down(void)
 {
-	u8 value;
+	u8 value = pci_read_config8(PCI_DEV(0, 2, 1), 0xf4);
 
-	if ((value = pci_read_config8(PCI_DEV(0, 2, 1), 0xf4)) > 0x10)
+	if (value > 0x10)
 		pci_write_config8(PCI_DEV(0, 2, 1), 0xf4,
 				  (value - 0x10) & 0xf0);
 }
@@ -55,16 +55,16 @@
 	printk(BIOS_DEBUG, "EC event %02x\n", event);
 
 	switch (event) {
-		case 0x14:
-			/* brightness up */
-			mainboard_smi_brightness_up();
-			break;
-		case 0x15:
-			/* brightness down */
-			mainboard_smi_brightness_down();
-			break;
-		default:
-			break;
+	case 0x14:
+		/* brightness up */
+		mainboard_smi_brightness_up();
+		break;
+	case 0x15:
+		/* brightness down */
+		mainboard_smi_brightness_down();
+		break;
+	default:
+		break;
 	}
 }
 
@@ -77,25 +77,25 @@
 int mainboard_smi_apmc(u8 data)
 {
 	switch (data) {
-		case APM_CNT_ACPI_ENABLE:
-			/* use 0x1600/0x1604 to prevent races with userspace */
-			ec_set_ports(0x1604, 0x1600);
-			/* route EC_SCI to SCI */
-			gpi_route_interrupt(GPE_EC_SCI, GPI_IS_SCI);
-			/* discard all events, and enable attention */
-			ec_write(0x80, 0x01);
-			break;
-		case APM_CNT_ACPI_DISABLE:
-			/* we have to use port 0x62/0x66, as 0x1600/0x1604 doesn't
-			   provide a EC query function */
-			ec_set_ports(0x66, 0x62);
-			/* route EC_SCI to SMI */
-			gpi_route_interrupt(GPE_EC_SCI, GPI_IS_SMI);
-			/* discard all events, and enable attention */
-			ec_write(0x80, 0x01);
-			break;
-		default:
-			break;
+	case APM_CNT_ACPI_ENABLE:
+		/* use 0x1600/0x1604 to prevent races with userspace */
+		ec_set_ports(0x1604, 0x1600);
+		/* route EC_SCI to SCI */
+		gpi_route_interrupt(GPE_EC_SCI, GPI_IS_SCI);
+		/* discard all events, and enable attention */
+		ec_write(0x80, 0x01);
+		break;
+	case APM_CNT_ACPI_DISABLE:
+		/* we have to use port 0x62/0x66, as 0x1600/0x1604 doesn't
+		   provide a EC query function */
+		ec_set_ports(0x66, 0x62);
+		/* route EC_SCI to SMI */
+		gpi_route_interrupt(GPE_EC_SCI, GPI_IS_SMI);
+		/* discard all events, and enable attention */
+		ec_write(0x80, 0x01);
+		break;
+	default:
+		break;
 	}
 	return 0;
 }
diff --git a/src/mainboard/lenovo/t430s/variants/t430s/board_info.txt b/src/mainboard/lenovo/t430s/variants/t430s/board_info.txt
new file mode 100644
index 0000000..783d563
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t430s/board_info.txt
@@ -0,0 +1,7 @@
+Category: laptop
+Board name: ThinkPad T430s
+ROM package: SOIC-8 / WSON-8
+ROM protocol: SPI
+ROM socketed: n
+Flashrom support: n
+Release year: 2012
diff --git a/src/mainboard/lenovo/t430s/data.vbt b/src/mainboard/lenovo/t430s/variants/t430s/data.vbt
similarity index 100%
rename from src/mainboard/lenovo/t430s/data.vbt
rename to src/mainboard/lenovo/t430s/variants/t430s/data.vbt
Binary files differ
diff --git a/src/mainboard/lenovo/t430s/gpio.c b/src/mainboard/lenovo/t430s/variants/t430s/gpio.c
similarity index 100%
rename from src/mainboard/lenovo/t430s/gpio.c
rename to src/mainboard/lenovo/t430s/variants/t430s/gpio.c
diff --git a/src/mainboard/lenovo/t430s/variants/t430s/hda_verb.c b/src/mainboard/lenovo/t430s/variants/t430s/hda_verb.c
new file mode 100644
index 0000000..f73434d
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t430s/hda_verb.c
@@ -0,0 +1,128 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
+ * Copyright (C) 2014 Vladimir Serbinenko
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*	Vendor Name    : Realtek
+ *	Vendor ID      : 0x10ec0269
+ *	Subsystem ID   : 0x17aa21fb
+ *	Revision ID    : 0x100203
+ */
+
+
+#include <device/azalia_device.h>
+
+const u32 cim_verb_data[] = {
+	/* coreboot specific header */
+	0x10ec0269,	// Codec Vendor / Device ID: Realtek ALC269VC
+	0x17aa21fb,	// Subsystem ID
+	0x00000013,	// Number of 4 dword sets
+
+/* Bits 31:28 - Codec Address */
+/* Bits 27:20 - NID */
+/* Bits 19:8 - Verb ID */
+/* Bits 7:0  - Payload */
+
+/* NID 0x01 - NodeInfo */
+	AZALIA_SUBVENDOR(0x0, 0x17AA21FB),
+
+/* NID 0x0A - External Microphone Connector
+ * Config=0x04A11020 (External,Right; MicIn,3.5mm; Black,JD; DA,Seq)
+ */
+	AZALIA_PIN_CFG(0x0, 0x0A, 0x04A11020),
+
+/* NID 0x0B - Headphone Connector
+ * Config=0x0421101F (External,Right; HP,3.5mm; Black,JD; DA,Seq)
+ */
+	AZALIA_PIN_CFG(0x0, 0x0B, 0x0421101F),
+
+/* NID 0x0C - Not connected
+ * Config=0x40F000F0 (N/A,N/A; Other,Unknown; Unknown,JD; DA,Seq)
+ */
+	AZALIA_PIN_CFG(0x0, 0x0C, 0x40F000F0),
+
+/* NID 0x0D - Internal Speakers
+ * Config=0x90170110 (Fixed,Int; Speaker,Other Analog; Unknown,nJD; DA,Seq)
+ */
+	AZALIA_PIN_CFG(0x0, 0x0D, 0x90170110),
+
+/* NID 0x0F - Not connected
+ * Config=0x40F000F0
+ */
+	AZALIA_PIN_CFG(0x0, 0x0F, 0x40F000F0),
+
+/* NID 0x11 - Internal Microphone
+ * Config=0xD5A30140 (Fixed internal,Top; Mic In,ATIPI; Unknown,nJD; DA,Seq)
+ */
+	AZALIA_PIN_CFG(0x0, 0x12, 0x90A60140),
+	AZALIA_PIN_CFG(0x0, 0x14, 0x90170110),
+	AZALIA_PIN_CFG(0x0, 0x15, 0x03211020),
+	AZALIA_PIN_CFG(0x0, 0x17, 0x411111F0),
+	AZALIA_PIN_CFG(0x0, 0x18, 0x03A11830),
+	AZALIA_PIN_CFG(0x0, 0x19, 0x411111F0),
+
+	0x01970804,
+	0x01870803,
+	0x01470740,
+	0x00970600,
+
+	AZALIA_PIN_CFG(0x0, 0x1A, 0x411111F0),
+	AZALIA_PIN_CFG(0x0, 0x1B, 0x411111F0),
+	AZALIA_PIN_CFG(0x0, 0x1D, 0x40138205),
+	AZALIA_PIN_CFG(0x0, 0x1E, 0x411111F0),
+
+	/* Misc entries */
+	0x00370600,
+	0x00270600,
+	0x00B707C0, /* Enable PortB as Output with HP amp */
+	0x00D70740, /* Enable PortD as Output */
+	0x0017A200, /* Disable ClkEn of PortSenseTst */
+	0x0017C621, /* Slave Port - Port A used as microphone input for
+		       combo Jack
+		       Master Port - Port B used for Jack Presence Detect
+		       Enable Combo Jack Detection */
+	0x0017A208, /* Enable ClkEn of PortSenseTst */
+	0x00170500, /* Set power state to D0 */
+
+	/* --- Next Codec --- */
+
+/*	Vendor Name    : Intel
+ *	Vendor ID      : 0x80862806
+ *	Subsystem ID   : 0x80860101
+ *	Revision ID    : 0x100000
+ */
+	/* coreboot specific header */
+	0x80862806,	// Codec Vendor / Device ID: Intel PantherPoint HDMI
+	0x80860101,	// Subsystem ID
+	0x00000004,	// Number of IDs
+
+	/* NID 0x01, HDA Codec Subsystem ID Verb Table: 0x80860101 */
+	AZALIA_SUBVENDOR(0x3, 0x80860101),
+
+	/* Pin Complex (NID 0x05) Digital Out at Int HDMI */
+	AZALIA_PIN_CFG(0x3, 0x05, 0x18560010),
+
+	/* Pin Complex (NID 0x06) Digital Out at Int HDMI */
+	AZALIA_PIN_CFG(0x3, 0x06, 0x18560020),
+
+	/* Pin Complex (NID 0x07) Digital Out at Int HDMI */
+	AZALIA_PIN_CFG(0x3, 0x07, 0x18560030)
+};
+
+const u32 pc_beep_verbs[] = {
+	/* Digital PCBEEP Gain: 0h=-9db, 1h=-6db ... 4h=+3db, 5h=+6db */
+	0x02177a00,
+};
+
+AZALIA_ARRAY_SIZES;
diff --git a/src/mainboard/lenovo/t430s/variants/t430s/overridetree.cb b/src/mainboard/lenovo/t430s/variants/t430s/overridetree.cb
new file mode 100644
index 0000000..ff30702
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t430s/overridetree.cb
@@ -0,0 +1,13 @@
+chip northbridge/intel/sandybridge
+	device domain 0 on
+		chip southbridge/intel/bd82x6x # Intel Series 7 Panther Point PCH
+			device pci 1f.0 on
+				chip ec/lenovo/h8
+					register "has_bdc_detection" = "1"
+					register "bdc_gpio_num" = "54"
+					register "bdc_gpio_lvl" = "0"
+				end
+			end # LPC Controller
+		end
+	end
+end
diff --git a/src/mainboard/lenovo/t430s/variants/t430s/romstage.c b/src/mainboard/lenovo/t430s/variants/t430s/romstage.c
new file mode 100644
index 0000000..1b1c4b2
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t430s/romstage.c
@@ -0,0 +1,67 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2007-2010 coresystems GmbH
+ * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
+ * Copyright (C) 2014 Vladimir Serbinenko
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <option.h>
+#include <arch/byteorder.h>
+#include <arch/io.h>
+#include <device/pci_def.h>
+#include <northbridge/intel/sandybridge/raminit_native.h>
+#include <southbridge/intel/bd82x6x/pch.h>
+#include <ec/lenovo/pmh7/pmh7.h>
+
+const struct southbridge_usb_port mainboard_usb_ports[] = {
+	{ 1, 0,  0 }, /* P0:, OC 0 */
+	{ 1, 1,  1 }, /* P1: (EHCI debug), OC 1 */
+	{ 1, 1,  3 }, /* P2:  OC 3 */
+	{ 1, 0, -1 }, /* P3: no OC */
+	{ 1, 2, -1 }, /* P4: no OC */
+	{ 1, 1, -1 }, /* P5: no OC */
+	{ 1, 1, -1 }, /* P6: no OC */
+	{ 0, 1, -1 }, /* P7: empty, no OC */
+	{ 1, 1, -1 }, /* P8: smart card reader, no OC */
+	{ 1, 0,  5 }, /* P9:  (EHCI debug), OC 5 */
+	{ 1, 0, -1 }, /* P10: fingerprint reader, no OC */
+	{ 1, 1, -1 }, /* P11: bluetooth, no OC. */
+	{ 0, 0, -1 }, /* P12: wlan, no OC */
+	{ 1, 1, -1 }, /* P13: camera, no OC */
+};
+
+void mainboard_get_spd(spd_raw_data *spd, bool id_only)
+{
+	read_spd(&spd[0], 0x50, id_only);
+	read_spd(&spd[2], 0x51, id_only);
+}
+
+void mainboard_early_init(int s3resume)
+{
+	u8 enable_peg;
+	if (get_option(&enable_peg, "enable_dual_graphics") != CB_SUCCESS)
+		enable_peg = 0;
+
+	bool power_en = pmh7_dgpu_power_state();
+
+	if (enable_peg != power_en)
+		pmh7_dgpu_power_enable(!power_en);
+
+	if (!enable_peg) {
+		// Hide disabled dGPU device
+		u32 reg32 = pci_read_config32(PCI_DEV(0, 0, 0), DEVEN);
+		reg32 &= ~DEVEN_PEG10;
+
+		pci_write_config32(PCI_DEV(0, 0, 0), DEVEN, reg32);
+	}
+}
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/board_info.txt b/src/mainboard/lenovo/t430s/variants/t431s/board_info.txt
new file mode 100644
index 0000000..bf05400
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/board_info.txt
@@ -0,0 +1,7 @@
+Category: laptop
+Board name: ThinkPad T431s baseboard
+ROM package: SOIC-8 / WSON-8
+ROM protocol: SPI
+ROM socketed: n
+Flashrom support: n
+Release year: 2013
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/data.vbt b/src/mainboard/lenovo/t430s/variants/t431s/data.vbt
new file mode 100644
index 0000000..e59ee83
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/data.vbt
Binary files differ
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/gpio.c b/src/mainboard/lenovo/t430s/variants/t431s/gpio.c
new file mode 100644
index 0000000..5e0684c
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/gpio.c
@@ -0,0 +1,206 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2008-2009 coresystems GmbH
+ * Copyright (C) 2014 Vladimir Serbinenko
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <southbridge/intel/common/gpio.h>
+
+static const struct pch_gpio_set1 pch_gpio_set1_mode = {
+	.gpio0 = GPIO_MODE_NATIVE,
+	.gpio1 = GPIO_MODE_GPIO,
+	.gpio2 = GPIO_MODE_NATIVE,
+	.gpio3 = GPIO_MODE_GPIO,
+	.gpio4 = GPIO_MODE_GPIO,
+	.gpio5 = GPIO_MODE_GPIO,
+	.gpio6 = GPIO_MODE_NATIVE,
+	.gpio7 = GPIO_MODE_NATIVE,
+	.gpio8 = GPIO_MODE_GPIO,
+	.gpio9 = GPIO_MODE_NATIVE,
+	.gpio10 = GPIO_MODE_GPIO,
+	.gpio11 = GPIO_MODE_NATIVE,
+	.gpio12 = GPIO_MODE_NATIVE,
+	.gpio13 = GPIO_MODE_GPIO,
+	.gpio14 = GPIO_MODE_NATIVE,
+	.gpio15 = GPIO_MODE_GPIO,
+	.gpio16 = GPIO_MODE_NATIVE,
+	.gpio17 = GPIO_MODE_NATIVE,
+	.gpio18 = GPIO_MODE_NATIVE,
+	.gpio19 = GPIO_MODE_NATIVE,
+	.gpio20 = GPIO_MODE_NATIVE,
+	.gpio21 = GPIO_MODE_GPIO,
+	.gpio22 = GPIO_MODE_NATIVE,
+	.gpio23 = GPIO_MODE_NATIVE,
+	.gpio24 = GPIO_MODE_GPIO,
+	.gpio25 = GPIO_MODE_NATIVE,
+	.gpio26 = GPIO_MODE_GPIO,
+	.gpio27 = GPIO_MODE_GPIO,
+	.gpio28 = GPIO_MODE_GPIO,
+	.gpio29 = GPIO_MODE_GPIO,
+	.gpio30 = GPIO_MODE_NATIVE,
+	.gpio31 = GPIO_MODE_GPIO,
+};
+
+static const struct pch_gpio_set1 pch_gpio_set1_direction = {
+	.gpio1 = GPIO_DIR_INPUT,
+	.gpio3 = GPIO_DIR_OUTPUT,
+	.gpio4 = GPIO_DIR_INPUT,
+	.gpio5 = GPIO_DIR_OUTPUT,
+	.gpio8 = GPIO_DIR_INPUT,
+	.gpio10 = GPIO_DIR_OUTPUT,
+	.gpio13 = GPIO_DIR_INPUT,
+	.gpio15 = GPIO_DIR_INPUT,
+	.gpio21 = GPIO_DIR_INPUT,
+	.gpio24 = GPIO_DIR_OUTPUT,
+	.gpio26 = GPIO_DIR_INPUT,
+	.gpio27 = GPIO_DIR_INPUT,
+	.gpio28 = GPIO_DIR_OUTPUT,
+	.gpio29 = GPIO_DIR_OUTPUT,
+	.gpio31 = GPIO_DIR_INPUT,
+};
+
+static const struct pch_gpio_set1 pch_gpio_set1_level = {
+	.gpio3 = GPIO_LEVEL_HIGH,
+	.gpio5 = GPIO_LEVEL_LOW,
+	.gpio10 = GPIO_LEVEL_HIGH,
+	.gpio24 = GPIO_LEVEL_HIGH,
+	.gpio28 = GPIO_LEVEL_LOW,
+	.gpio29 = GPIO_LEVEL_HIGH,
+};
+
+static const struct pch_gpio_set1 pch_gpio_set1_reset = {
+	.gpio24 = GPIO_RESET_RSMRST,
+};
+
+static const struct pch_gpio_set1 pch_gpio_set1_invert = {
+	.gpio1 = GPIO_INVERT,
+	.gpio13 = GPIO_INVERT,
+};
+
+static const struct pch_gpio_set1 pch_gpio_set1_blink = {
+};
+
+static const struct pch_gpio_set2 pch_gpio_set2_mode = {
+	.gpio32 = GPIO_MODE_NATIVE,
+	.gpio33 = GPIO_MODE_NATIVE,
+	.gpio34 = GPIO_MODE_GPIO,
+	.gpio35 = GPIO_MODE_GPIO,
+	.gpio36 = GPIO_MODE_GPIO,
+	.gpio37 = GPIO_MODE_GPIO,
+	.gpio38 = GPIO_MODE_GPIO,
+	.gpio39 = GPIO_MODE_GPIO,
+	.gpio40 = GPIO_MODE_NATIVE,
+	.gpio41 = GPIO_MODE_NATIVE,
+	.gpio42 = GPIO_MODE_NATIVE,
+	.gpio43 = GPIO_MODE_GPIO,
+	.gpio44 = GPIO_MODE_GPIO,
+	.gpio45 = GPIO_MODE_GPIO,
+	.gpio46 = GPIO_MODE_NATIVE,
+	.gpio47 = GPIO_MODE_GPIO,
+	.gpio48 = GPIO_MODE_GPIO,
+	.gpio49 = GPIO_MODE_GPIO,
+	.gpio50 = GPIO_MODE_GPIO,
+	.gpio51 = GPIO_MODE_NATIVE,
+	.gpio52 = GPIO_MODE_NATIVE,
+	.gpio53 = GPIO_MODE_NATIVE,
+	.gpio54 = GPIO_MODE_NATIVE,
+	.gpio55 = GPIO_MODE_NATIVE,
+	.gpio56 = GPIO_MODE_GPIO,
+	.gpio57 = GPIO_MODE_GPIO,
+	.gpio58 = GPIO_MODE_NATIVE,
+	.gpio59 = GPIO_MODE_NATIVE,
+	.gpio60 = GPIO_MODE_NATIVE,
+	.gpio61 = GPIO_MODE_NATIVE,
+	.gpio62 = GPIO_MODE_NATIVE,
+	.gpio63 = GPIO_MODE_NATIVE,
+};
+
+static const struct pch_gpio_set2 pch_gpio_set2_direction = {
+	.gpio34 = GPIO_DIR_INPUT,
+	.gpio35 = GPIO_DIR_INPUT,
+	.gpio36 = GPIO_DIR_INPUT,
+	.gpio37 = GPIO_DIR_INPUT,
+	.gpio38 = GPIO_DIR_INPUT,
+	.gpio39 = GPIO_DIR_INPUT,
+	.gpio43 = GPIO_DIR_OUTPUT,
+	.gpio44 = GPIO_DIR_INPUT,
+	.gpio45 = GPIO_DIR_INPUT,
+	.gpio47 = GPIO_DIR_INPUT,
+	.gpio48 = GPIO_DIR_INPUT,
+	.gpio49 = GPIO_DIR_INPUT,
+	.gpio50 = GPIO_DIR_INPUT,
+	.gpio56 = GPIO_DIR_INPUT,
+	.gpio57 = GPIO_DIR_INPUT,
+};
+
+static const struct pch_gpio_set2 pch_gpio_set2_level = {
+	.gpio43 = GPIO_LEVEL_HIGH,
+};
+
+static const struct pch_gpio_set2 pch_gpio_set2_reset = {
+};
+
+static const struct pch_gpio_set3 pch_gpio_set3_mode = {
+	.gpio64 = GPIO_MODE_GPIO,
+	.gpio65 = GPIO_MODE_GPIO,
+	.gpio66 = GPIO_MODE_GPIO,
+	.gpio67 = GPIO_MODE_GPIO,
+	.gpio68 = GPIO_MODE_NATIVE,
+	.gpio69 = GPIO_MODE_GPIO,
+	.gpio70 = GPIO_MODE_GPIO,
+	.gpio71 = GPIO_MODE_GPIO,
+	.gpio72 = GPIO_MODE_NATIVE,
+	.gpio73 = GPIO_MODE_NATIVE,
+	.gpio74 = GPIO_MODE_NATIVE,
+	.gpio75 = GPIO_MODE_NATIVE,
+};
+
+static const struct pch_gpio_set3 pch_gpio_set3_direction = {
+	.gpio64 = GPIO_DIR_INPUT,
+	.gpio65 = GPIO_DIR_INPUT,
+	.gpio66 = GPIO_DIR_INPUT,
+	.gpio67 = GPIO_DIR_INPUT,
+	.gpio69 = GPIO_DIR_INPUT,
+	.gpio70 = GPIO_DIR_INPUT,
+	.gpio71 = GPIO_DIR_INPUT,
+};
+
+static const struct pch_gpio_set3 pch_gpio_set3_level = {
+};
+
+static const struct pch_gpio_set3 pch_gpio_set3_reset = {
+};
+
+const struct pch_gpio_map mainboard_gpio_map = {
+	.set1 = {
+		.mode		= &pch_gpio_set1_mode,
+		.direction	= &pch_gpio_set1_direction,
+		.level		= &pch_gpio_set1_level,
+		.blink		= &pch_gpio_set1_blink,
+		.invert		= &pch_gpio_set1_invert,
+		.reset		= &pch_gpio_set1_reset,
+	},
+	.set2 = {
+		.mode		= &pch_gpio_set2_mode,
+		.direction	= &pch_gpio_set2_direction,
+		.level		= &pch_gpio_set2_level,
+		.reset		= &pch_gpio_set2_reset,
+	},
+	.set3 = {
+		.mode		= &pch_gpio_set3_mode,
+		.direction	= &pch_gpio_set3_direction,
+		.level		= &pch_gpio_set3_level,
+		.reset		= &pch_gpio_set3_reset,
+	},
+};
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/hda_verb.c b/src/mainboard/lenovo/t430s/variants/t431s/hda_verb.c
new file mode 100644
index 0000000..179fba0
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/hda_verb.c
@@ -0,0 +1,76 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2008-2009 coresystems GmbH
+ * Copyright (C) 2014 Vladimir Serbinenko
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <device/azalia_device.h>
+
+const u32 cim_verb_data[] = {
+	0x10ec0269, /* Codec Vendor / Device ID: Realtek */
+	0x17aa2208, /* Subsystem ID */
+
+	0x0000000b, /* Number of 4 dword sets */
+	/* NID 0x01: Subsystem ID.  */
+	AZALIA_SUBVENDOR(0x0, 0x17aa2208),
+
+	/* NID 0x12.  */
+	AZALIA_PIN_CFG(0x0, 0x12, 0x90a60140),
+
+	/* NID 0x14.  */
+	AZALIA_PIN_CFG(0x0, 0x14, 0x90170110),
+
+	/* NID 0x15.  */
+	AZALIA_PIN_CFG(0x0, 0x15, 0x03211020),
+
+	/* NID 0x17.  */
+	AZALIA_PIN_CFG(0x0, 0x17, 0x40008000),
+
+	/* NID 0x18.  */
+	AZALIA_PIN_CFG(0x0, 0x18, 0x03a11030),
+
+	/* NID 0x19.  */
+	AZALIA_PIN_CFG(0x0, 0x19, 0x411111f0),
+
+	/* NID 0x1a.  */
+	AZALIA_PIN_CFG(0x0, 0x1a, 0x411111f0),
+
+	/* NID 0x1b.  */
+	AZALIA_PIN_CFG(0x0, 0x1b, 0x411111f0),
+
+	/* NID 0x1d.  */
+	AZALIA_PIN_CFG(0x0, 0x1d, 0x40f38205),
+
+	/* NID 0x1e.  */
+	AZALIA_PIN_CFG(0x0, 0x1e, 0x411111f0),
+	0x80862806, /* Codec Vendor / Device ID: Intel */
+	0x80860101, /* Subsystem ID */
+
+	0x00000004, /* Number of 4 dword sets */
+	/* NID 0x01: Subsystem ID.  */
+	AZALIA_SUBVENDOR(0x3, 0x80860101),
+
+	/* NID 0x05.  */
+	AZALIA_PIN_CFG(0x3, 0x05, 0x18560010),
+
+	/* NID 0x06.  */
+	AZALIA_PIN_CFG(0x3, 0x06, 0x18560020),
+
+	/* NID 0x07.  */
+	AZALIA_PIN_CFG(0x3, 0x07, 0x18560030),
+};
+
+const u32 pc_beep_verbs[0] = {};
+
+AZALIA_ARRAY_SIZES;
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/overridetree.cb b/src/mainboard/lenovo/t430s/variants/t431s/overridetree.cb
new file mode 100644
index 0000000..e69f727
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/overridetree.cb
@@ -0,0 +1,75 @@
+chip northbridge/intel/sandybridge
+	# Enable DisplayPort Hotplug with 6ms pulse
+	register "gpu_dp_b_hotplug" = "4"
+	register "gpu_dp_c_hotplug" = "4"
+	register "gpu_dp_d_hotplug" = "4"
+
+	# Enable Panel as eDP and configure power delays
+	register "gpu_panel_port_select" = "1"			# eDP
+	register "gpu_panel_power_up_delay" = "2000"		# 200ms
+	register "gpu_panel_power_down_delay" = "500"		# 50ms
+	register "gpu_panel_power_backlight_on_delay" = "1"	# 0.1ms
+	register "gpu_panel_power_backlight_off_delay" = "1"	# 0.1ms
+	register "gpu_cpu_backlight" = "0x03d2"
+
+	device domain 0 on
+		device pci 00.0 on
+			subsystemid 0x17aa 0x2208
+		end # host bridge
+		device pci 01.0 off end # PCIe Bridge for discrete graphics
+		device pci 02.0 on
+			subsystemid 0x17aa 0x2208
+		end # Integrated Graphics Controller
+		chip southbridge/intel/bd82x6x # Intel Series 7 Panther Point PCH
+			# Enable SATA ports 0 (HDD bay) & 1 (WWAN M.2 SATA) & 4 (dock)
+			register "sata_port_map" = "0x13"
+			# T431s has no Express Card slot.
+			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
+			device pci 14.0 on
+				subsystemid 0x17aa 0x2208
+			end # USB 3.0 Controller
+			device pci 1a.0 on
+				subsystemid 0x17aa 0x2208
+			end # USB Enhanced Host Controller #2
+			device pci 1b.0 on
+				subsystemid 0x17aa 0x2208
+			end # High Definition Audio Controller
+			device pci 1c.0 on # PCIe Port #1
+				subsystemid 0x17aa 0x2208
+				chip drivers/ricoh/rce822 # Ricoh cardreader
+					register "disable_mask" = "0x87"
+					register "sdwppol" = "0"
+					device pci 00.0 on # Ricoh SD card reader
+						subsystemid 0x17aa 0x2208
+					end
+				end
+			end
+			device pci 1c.1 on
+				subsystemid 0x17aa 0x2208
+			end # PCIe Port #2 Integrated Wireless LAN
+			device pci 1c.2 off end # PCIe Port #3
+			device pci 1d.0 on
+				subsystemid 0x17aa 0x2208
+			end # USB Enhanced Host Controller #1
+			device pci 1e.0 off end # PCI bridge
+			device pci 1f.0 on
+				subsystemid 0x17aa 0x2208
+				chip ec/lenovo/h8
+					register "config0" = "0xa6"
+					register "config1" = "0x09"
+					register "config3" = "0xc0"
+					register "evente_enable" = "0x1d"
+					# T431s only has BT on wlan card
+					register "has_bdc_detection" = "0"
+				end
+			end # LPC Controller
+			device pci 1f.2 on
+				subsystemid 0x17aa 0x2208
+			end # 6 port SATA AHCI Controller
+			device pci 1f.3 on
+				subsystemid 0x17aa 0x2208
+			end # SMBus Controller
+			device pci 1f.6 off end # Thermal
+		end
+	end
+end
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/romstage.c b/src/mainboard/lenovo/t430s/variants/t431s/romstage.c
new file mode 100644
index 0000000..66e28ad
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/romstage.c
@@ -0,0 +1,61 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2007-2010 coresystems GmbH
+ * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
+ * Copyright (C) 2014 Vladimir Serbinenko
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <option.h>
+#include <arch/byteorder.h>
+#include <arch/io.h>
+#include <device/pci_def.h>
+#include <console/console.h>
+#include <cbfs.h>
+#include <northbridge/intel/sandybridge/raminit_native.h>
+#include <southbridge/intel/bd82x6x/pch.h>
+#include <ec/lenovo/pmh7/pmh7.h>
+
+const struct southbridge_usb_port mainboard_usb_ports[] = {
+	{ 1, 0, 0 },  /* SSP1: right */
+	{ 1, 0, 1 },  /* SSP2: left, EHCI Debug */
+	{ 1, 1, 3 },  /* SSP3: dock usb3 */
+	{ 1, 1, -1 }, /* B0P4: wwan usb */
+	{ 1, 1, 2 },  /* B0P5: dock usb2 */
+	{ 0, 0, -1 }, /* B0P6 */
+	{ 0, 0, -1 }, /* B0P7 */
+	{ 1, 2, -1 }, /* B0P8: unknown */
+	{ 1, 0, -1 }, /* B1P1: smart card reader */
+	{ 0, 2, 5 },  /* B1P2 */
+	{ 1, 1, -1 }, /* B1P3: fingerprint reader */
+	{ 0, 0, -1 }, /* B1P4 */
+	{ 1, 1, -1 }, /* B1P5: wlan usb */
+	{ 1, 1, -1 }, /* B1P6: Camera */
+};
+
+void mainboard_get_spd(spd_raw_data *spd, bool id_only)
+{
+	/* C1S0 is a soldered RAM with no real SPD. Use stored SPD.  */
+	size_t spd_file_len = 0;
+	void *spd_file = cbfs_boot_map_with_leak("spd.bin", CBFS_TYPE_SPD,
+		&spd_file_len);
+
+	if (!spd_file || spd_file_len < sizeof(spd_raw_data))
+		die("SPD data for C1S0 not found.");
+
+	memcpy(&spd[0], spd_file, spd_file_len);
+	read_spd(&spd[2], 0x51, id_only);
+}
+
+void mainboard_early_init(int s3resume)
+{
+}
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/spd/Makefile.inc b/src/mainboard/lenovo/t430s/variants/t431s/spd/Makefile.inc
new file mode 100644
index 0000000..4b9ef55
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/spd/Makefile.inc
@@ -0,0 +1,31 @@
+##
+## This file is part of the coreboot project.
+##
+## Copyright (C) 2016 Alexander Couzens <lynxis@fe80.eu>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; version 2 of the License.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+
+SPD_BIN = $(obj)/spd.bin
+
+SPD_SOURCES  = samsung_4gb  # 0b0010 4GiB
+SPD_DEPS := $(foreach f, $(SPD_SOURCES), src/mainboard/$(MAINBOARDDIR)/variants/$(VARIANT_DIR)/spd/$(f).spd.hex)
+
+# Include spd ROM data
+$(SPD_BIN): $(SPD_DEPS)
+	for f in $+; \
+	  do for c in $$(cat $$f | grep -v ^#); \
+	    do printf $$(printf '\%o' 0x$$c); \
+	  done; \
+	done > $@
+
+cbfs-files-y += spd.bin
+spd.bin-file := $(SPD_BIN)
+spd.bin-type := spd
diff --git a/src/mainboard/lenovo/t430s/variants/t431s/spd/samsung_4gb.spd.hex b/src/mainboard/lenovo/t430s/variants/t431s/spd/samsung_4gb.spd.hex
new file mode 100644
index 0000000..544d576
--- /dev/null
+++ b/src/mainboard/lenovo/t430s/variants/t431s/spd/samsung_4gb.spd.hex
@@ -0,0 +1,16 @@
+92 11 0b 03 04 00 00 01 03 52 01 08 0a 00 80 00
+6e 78 6e 32 6e 11 18 81 20 08 3c 3c 00 f0 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 65 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 b6 3b
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00