Flashing the T400 with a BeagleBone Black

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Initial flashing instructions for T400.

This guide is for those who want libreboot on their ThinkPad T400 while they still have the original Lenovo BIOS present. This guide can also be followed (adapted) if you brick your T400, to know how to recover.

An “HMM” (Hardware Maintenance Manual) detailing the process of [dis]assembly is available for this model. Be careful when reassembling the laptop as the screws on page 114 (with title “1130 Keyboard bezel”) are swapped and if you follow the HMM you will punch a hole through the bezel in the upper right corner.

Serial port

EHCI debug might not be needed. It has been reported that the docking station for this laptop has a serial port, so it might be possible to use that instead.

A note about CPUs

ThinkWiki has a list of CPUs for this system. The Core 2 Duo P8400, P8600 and P8700 are believed to work in libreboot.

T9600, T9500, T9550 and T9900 are all compatible, as reported by users.

Quad-core CPUs

Very likely to be compatible, but requires hardware modification. Based on info from German forum post about installing Core Quad CPU on T500 found in coreboot mailing list. Currently work in progress and no guide available.

A note about GPUs

Some models have an Intel GPU, while others have both an ATI and an Intel GPU; this is referred to as “switchable graphics”. In the BIOS setup program for lenovobios, you can specify that the system will use one or the other (but not both).

Libreboot is known to work on systems with only the Intel GPU, using native graphics initialization. On systems with switchable graphics, the Intel GPU is used and the ATI GPU is disabled, so native graphics initialization works all the same.

CPU paste required

See #paste.

Flash chip size

Use this to find out:

# flashrom -p internal

MAC address

Refer to mac_address.html.

Initial BBB configuration

Refer to bbb_setup.html for how to configure the BBB for flashing.

The following shows how to connect clip to the BBB (on the P9 header), for SOIC-16 (clip: Pomona 5252):

POMONA 5252 (correlate with the BBB guide)
===  ethernet jack and VGA port ====
 NC              -       - 21
 1               -       - 17
 NC              -       - NC
 NC              -       - NC
 NC              -       - NC
 NC              -       - NC
 18              -       - 3.3V (PSU)
 22              -       - NC - this is pin 1 on the flash chip
===  SATA port ===
This is how you will connect. Numbers refer to pin numbers on the BBB, on the plugs near the DC jack.

The following shows how to connect clip to the BBB (on the P9 header), for SOIC-8 (clip: Pomona 5250):

POMONA 5250 (correlate with the BBB guide)
===  RAM slots ====
 18              -       - 1
 22              -       - NC
 NC              -       - 21
 3.3V (PSU)      -       - 17 - this is pin 1 on the flash chip
===  slot where the AC jack is connected ===

This is how you will connect. Numbers refer to pin numbers on the BBB, on the plugs near the DC jack.

The procedure

Remove all screws, placing them in the order that you removed them:

Remove those three screws then remove the rear bezel:

Remove the speakers:

Remove the wifi:

Remove this cable:

Unroute those antenna wires:

Remove the LCD assembly:

Disconnect the NVRAM battery:

Disconnect the fan:

Unscrew these:

Unscrew the heatsink, then lift it off:

Disconnect the power jack:

Loosen this:

Remove this:

Unscrew these:

Remove this:

Unscrew this:

Remove the motherboard (the cage is still attached) from the right hand side, then lift it out:

Remove these screws, placing the screws in the same layout and marking each screw hole (so that you know what ones to put the screws back into later):

Separate the motherboard:

Connect your programmer, then connect GND and 3.3V

A dedicated 3.3V PSU was used to create this guide, but at ATX PSU is also fine:

Of course, make sure to turn on your PSU:

Now, you should be ready to install libreboot.

Flashrom binaries for ARM (tested on a BBB) are distributed in libreboot_util. Alternatively, libreboot also distributes flashrom source code which can be built.

Log in as root on your BBB, using the instructions in bbb_setup.html#bbb_access.

Test that flashrom works:

# ./flashrom -p linux_spi:dev=/dev/spidev1.0,spispeed=512

In this case, the output was:

flashrom v0.9.7-r1854 on Linux 3.8.13-bone47 (armv7l)
flashrom is free software, get the source code at http://www.flashrom.org
Calibrating delay loop... OK.
Found Macronix flash chip "MX25L6405(D)" (8192 kB, SPI) on linux_spi.
Found Macronix flash chip "MX25L6406E/MX25L6436E" (8192 kB, SPI) on linux_spi.
Found Macronix flash chip "MX25L6445E/MX25L6473E" (8192 kB, SPI) on linux_spi.
Multiple flash chip definitions match the detected chip(s): "MX25L6405(D)", "MX25L6406E/MX25L6436E", "MX25L6445E/MX25L6473E"
Please specify which chip definition to use with the -c <chipname> option.

How to backup factory.rom (change the -c option as needed, for your flash chip):

# ./flashrom -p linux_spi:dev=/dev/spidev1.0,spispeed=512 -r factory.rom

# ./flashrom -p linux_spi:dev=/dev/spidev1.0,spispeed=512 -r factory1.rom

# ./flashrom -p linux_spi:dev=/dev/spidev1.0,spispeed=512 -r factory2.rom

Note: the -c option is not required in libreboot’s patched flashrom, because the redundant flash chip definitions in flashchips.c have been removed.

Now compare the 3 images:

# sha512sum factory*.rom

If the hashes match, then just copy one of them (the factory.rom) to a safe place (on a drive connected to another system, not the BBB). This is useful for reverse engineering work, if there is a desirable behaviour in the original firmware that could be replicated in coreboot and libreboot.

While there is a default MAC address inside the gbe region of flash image, it is not one you want to use. Make sure to change the MAC address to the one that is correct for your system, for later internal flash, but always remember to flash unmodfied txtmode image first as it is known to work and only this variant provides memtest. You can follow instructions at ../hardware/gm45_remove_me.html#ich9gen to change the MAC address inside the libreboot image.

Now flash it:

# ./flashrom -p linux_spi:dev=/dev/spidev1.0,spispeed=512 -w path/to/libreboot/rom/image.rom -V

You might see errors, but if it says Verifying flash... VERIFIED at the end, then it’s flashed and should boot. If you see errors, try again (and again, and again); the message Chip content is identical to the requested image is also an indication of a successful installation.

Example output from running the command (see above):

flashrom v0.9.7-r1854 on Linux 3.8.13-bone47 (armv7l)
flashrom is free software, get the source code at http://www.flashrom.org
Calibrating delay loop... OK.
Found Macronix flash chip "MX25L6405(D)" (8192 kB, SPI) on linux_spi.
Reading old flash chip contents... done.
Erasing and writing flash chip... FAILED at 0x00001000! Expected=0xff, Found=0x00, failed byte count from 0x00000000-0x0000ffff: 0xd716
Reading current flash chip contents... done. Looking for another erase function.
Erase/write done.
Verifying flash... VERIFIED.

Thermal paste (IMPORTANT)

Because part of this procedure involved removing the heatsink, you will need to apply new paste. Arctic MX-4 is ok. You will also need isopropyl alcohol and an anti-static cloth to clean with.

When re-installing the heatsink, you must first clean off all old paste with the alcohol/cloth. Then apply new paste. Arctic MX-4 is also much better than the default paste used on these systems.

NOTE: the photo above is for illustration purposes only, and does not show how to properly apply the thermal paste. Other guides online detail the proper application procedure.


The T400 typically comes with an Intel wifi chipset, which does not work without proprietary software. For a list of wifi chipsets that work without proprietary software, see ../hardware/#recommended_wifi.

Some T400 laptops might come with an Atheros chipset, but this is 802.11g only.

It is recommended that you install a new wifi chipset. This can only be done after installing libreboot, because the original firmware has a whitelist of approved chips, and it will refuse to boot if you use an ‘unauthorized’ wifi card.

The following photos show an Atheros AR5B95 being installed, to replace the Intel chip that this T400 came with:


If you have a WWAN/3G card and/or sim card reader, remove them permanently. The WWAN-3G card has proprietary firmware inside; the technology is identical to what is used in mobile phones, so it can also track your movements.

Not to be confused with wifi (wifi is fine).


In DDR3 machines with Cantiga (GM45/GS45/PM45), northbridge requires sticks that will work as PC3-8500 (faster PC3/PC3L sticks can work as PC3-8500). Non-matching pairs may not work. Single module (meaning, one of the slots will be empty) will currently only work in slot 0.

NOTE: according to users reports, non matching pairs (e.g. 1+2 GiB) might work in some cases.

Make sure that the RAM you buy is the 2Rx8 configuration when buying 4GiB sticks (In other words: maximum of 2GiB per rank, 2 ranks per card).

This page might be useful for RAM compatibility info (note: coreboot raminit is different, so this page might be BS)

The following photo shows 8GiB (2x4GiB) of RAM installed:

Boot it!

You should see something like this:

Now install GNU+Linux.

Copyright © 2015 Leah Rowe info@minifree.org

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License Version 1.3 or any later version published by the Free Software Foundation with no Invariant Sections, no Front Cover Texts, and no Back Cover Texts. A copy of this license is found in ../fdl-1.3.html

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