mainboard/lenovo/x230: Add ThinkPad x230s as a variant

The code is based on autoport and that for X230. Major differences are:
    - Only one DDR3 slot
    - HM77 PCH
    - M.2 socket instead of mini pci-e
    - no docking
    - no tpm

Tested:
    - CPU i5-3337U
    - Slotted DIMM 8GiB
    - 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
    - Linux 4.9 within Debian GNU/Linux stable, loaded from
      Seabios.

Untested:
    - Touch screen, which is said to work under ubuntu but not debian.

Change-Id: Ie537645d5ffaee799e79af2f821f80c3ebd2dfec
Signed-off-by: Bill XIE <persmule@hardenedlinux.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41168
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/mainboard/lenovo/x230/variants/x230/overridetree.cb b/src/mainboard/lenovo/x230/variants/x230/overridetree.cb
new file mode 100644
index 0000000000..8f1a97d9dd
--- /dev/null
+++ b/src/mainboard/lenovo/x230/variants/x230/overridetree.cb
@@ -0,0 +1,15 @@
+chip northbridge/intel/sandybridge
+	device domain 0x0 on
+		chip southbridge/intel/bd82x6x # Intel Series 6 Cougar Point PCH
+			register "docking_supported" = "1"
+			device pci 1c.2 on
+				smbios_slot_desc "7" "3" "ExpressCard Slot" "8"
+			end # PCIe Port #3 (expresscard)
+			device pci 1f.0 on # LPC bridge
+				chip ec/lenovo/h8
+					register "eventa_enable" = "0x01"
+				end
+			end # LPC Controller
+		end
+	end
+end