mainboard: Add Lenovo ThinkPad T440p

The code is based on autoport.

This port is tested on a T440p without a dGPU and can boot Arch Linux
from SATA disk with SeaBIOS payload. The tested components and issues
are in the documentation.

Change-Id: I56a6b94197789a83731d8b349b8ba6814bf57ca2
Signed-off-by: Iru Cai <mytbk920423@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34359
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

Documentation/mainboard/index.md

@@ -91,6 +91,10 @@ The boards in this section are not real mainboards, but emulators.
 - [T430 / T530 / X230 / W530 common](lenovo/xx30_series.md)
 - [T431s](lenovo/t431s.md)
 
+### Haswell series
+
+- [T440p](lenovo/t440p.md)
+
 ## Portwell
 
 - [PQ7-M107](portwell/pq7-m107.md)

Documentation/mainboard/lenovo/t440p.md

@@ -0,0 +1,66 @@
+# Lenovo ThinkPad T440p
+
+This page describes how to run coreboot on [Lenovo ThinkPad T440p].
+
+## Required proprietary blobs
+
+Please see [mrc.bin](../../northbridge/intel/haswell/mrc.bin).
+
+## Flashing instructions
+
+T440p has two flash chips, an 8MB W25Q64FV and a 4MB W25Q32FV. To flash
+coreboot, you just need to remove the big door according to the T440
+[Hardware Maintenance Manual] and flash the 4MB chip.
+
+![T440p flash chip](t440p_flash_chip.jpg)
+
+To access the 8MB chip, you need to remove the base cover.
+
+![T440p 8MB flash chip](t440p_all_flash_chips.jpg)
+
+The flash layout of the OEM firmware is as follows:
+
+    00000000:00000fff fd
+    00001000:00002fff gbe
+    00003000:004fffff me
+    00500000:00bfffff bios
+
+After flashing coreboot, you may need to re-plug the AC adapter to make
+the laptop able to power on.
+
+## Known Issues
+
+- No audio output when using a headphone
+- The touchpad is misconfigured, the 3 keys on top are all identified
+  as left button
+- Cannot get the mainboard serial number from the mainboard: the OEM
+  UEFI firmware gets the serial number from an "emulated EEPROM" via
+  I/O port 0x1630/0x1634, but it's still unknown how to make it work
+
+## Untested
+
+- the dGPU model
+
+## Working
+
+- boot Arch Linux with Linux 4.19.77 from SeaBIOS payload
+- integrated graphics init with libgfxinit
+- EHCI debug: the port is the non-charging USB2 port on the right
+- video output: internal (eDP), miniDP, dock DP, dock HDMI
+- ACPI support
+- keyboard and trackpoint
+- SATA
+- M.2 SATA SSD
+- USB
+- Ethernet
+- WLAN
+- WWAN
+- bluetooth
+- virtualization: VT-x and VT-d
+- dock
+- CMOS options: wlan, trackpoint, fn_ctrl_swap
+- internal flashing when IFD is unlocked
+- using `me_cleaner`
+
+[Lenovo ThinkPad T440p]: https://pcsupport.lenovo.com/us/zh/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t440p
+[Hardware Maintenance Manual]: https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/t440p_hmm_en_sp40a25467_04.pdf