coreboot-x230

pre-built coreboot images and documentation on how to flash them for the Thinkpad X230

These images

• include SeaBIOS as coreboot payload, for maximum compatibility.
• are meant to be flashed externally
• are compatible with Windows and Linux

Latest build (config overview and version info)

See our releases

• Lenovo's proprietary VGA BIOS ROM is executed in "secure" mode

coreboot

• We simply take coreboot's current state in it's master branch at the time we build a release image. That's the preferred way to use coreboot. The git revision we use is always included in the release.

Intel microcode

• version 20180108
• in 20180108, for the X230's CPU ID (306ax) the latest update is 2015-02-26
• (not yet in coreboot upstream)

SeaBIOS

• version 1.11.0 from 2017-11-10
• (in coreboot upstream)

When do we do a release?

Either when

• There is a new SeaBIOS release,
• There is a new Intel microcode release (included in coreboot AND affecting our CPU ID),
• There is a coreboot issue that affects us (unlikely), or
• We need to change the config

TL;DR

Download a released image, connect your hardware SPI flasher to the "upper" 4MB chip in your X230, and do

 flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -w x230_coreboot_seabios_example_top.rom

Flashing for the first time

EC firmware (optional)

Enter Lenovo's BIOS with F1 and check the embedded controller (EC) version to be 1.14 and upgrade using the latest bootable CD if it isn't. The EC cannot be upgraded when coreboot is installed. (In case a newer version should ever be available (I doubt it), you could temporarily flash back your original Lenovo BIOS image)

me_cleaner (optional)

The Intel Management Engine resides on the 8MB chip. We don't need to touch it for coreboot-upgrades in the future, but while opening up the Thinkpad anyways, we can save it and run ifdtool and me_cleaner on it:

  flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -c "MX25L3206E/MX25L3208E" -r ifdmegbe.rom
  flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -c "MX25L3206E/MX25L3208E" -r ifdmegbe2.rom
  diff ifdmegbe.rom ifdmegbe2.rom
  git clone https://github.com/corna/me_cleaner.git && cd me_cleaner
  ./me_cleaner.py -S -O ifdmegbe_meclean.rom ifdmegbe.rom
  ifdtool -u ifdmegbe_meclean.rom
  flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -c "MX25L3206E/MX25L3208E" -w ifdmegbe_meclean.rom.new

save the 4MB chip

(internally, memory of the two chips is mapped together, the 8MB being the lower part, but we can essientially ignore that)

For the first time, we have to save the original image, just like we did with the 8MB chip. It's important to keep this image somewhere safe:

  flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -r top1.rom
  flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -r top2.rom
  diff top1.rom top2.rom

Flashing the coreboot / SeaBIOS image

When upgrading to a new version, for example when a new SeaBIOS version is available, only the "upper" 4MB chip has to be written.

Download the latest release image we provide here and flash it:

 flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -w x230_coreboot_seabios_example_top.rom

How to flash

We flash externally, using a "Pomona 5250 8-pin SOIC test clip". You'll find one easily. This is how the X230's SPI connection looks on both chips:

    Screen (furthest from you)
             __
      MOSI  5 --|  |-- 4  GND
       CLK  6 --|  |-- 3  N/C
       N/C  7 --|  |-- 2  MISO
       VCC  8 --|__|-- 1  CS

       Edge (closest to you)

Example: Raspberry Pi 3

We run Raspbian and have the following setup

• Serial connection using a "USB to Serial" Adapter and picocom or minicom

• in the SD Cards's /boot/config.txt file enable_uart=1 and dtparam=spi=on

• For flashrom we put spi_bcm2835 and spidev in /etc/modules

• Connect to a wifi or to network over ethernet.

• install flashrom

• connect the Clip to the Raspberry Pi 3:

       Edge of pi (furthest from you)
                   (UART)
     L           GND TX  RX                           CS
     E            |   |   |                           |
     F +---------------------------------------------------------------------------------+
     T |  x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x  |
       |  x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x   x  |
     E +----------------------------------^---^---^---^-------------------------------^--+
     D                                    |   |   |   |                               |
     G                                   3.3V MOSIMISO|                              GND
     E                                 (VCC)         CLK
       Body of Pi (closest to you)
  

Now you should be able to copy the image over to your Rasperry Pi and run the mentioned flashrom commands. One way to copy, is convertig it to ascii using uuencode (part of Debian's sharutils package) described below. Another way is of course using a USB Stick :)

    (convert)
host$ uuencode coreboot.rom coreboot.rom.ascii > coreboot.rom.ascii
    (transfer)
rpi$ cat > coreboot.rom.ascii
host$ pv coreboot.rom.ascii > /dev/ttyUSBX
    (wait)
rpi$ (CTRL-D)
    (convert back)
rpi$ uudecode -o coreboot.rom coreboot.rom.ascii
    (verify)
host$ sha1sum coreboot.rom
rpi$ sha1sum coreboot.rom

How we build

Everything necessary to build coreboot is included in this project and building coreboot is not hard at all. Please refer to coreboot's own documentation.

When building, testing and doing a release here, we always try to upload our result to coreboot's board status project.

Why does this work?

On the X230, there are 2 physical "BIOS" chips. The "upper" 4MB one holds the actual bios we can generate using coreboot, and the "lower" 8MB one holds the rest that you can modify yourself once, if you like, but strictly speaking, you don't need to touch it at all. What's this "rest"? Mainly a tiny binary used by the Ethernet card and the Intel Management Engine.