Patrick Rudolph 0751d7bded Documentation: Add tutorial for me_cleaner on Lenovo devices

Add a tutorial how to use ME cleaner, and give some basic steps to
strip the ME. Update the Lenovo Sandy Bridge documentation that no
issues could be observed on X220 and give an example flash layout.

Tested on Lenovo X220 with stripped ME and found no issues:
commit: cbc5b99ac9

* Displayport
* VGA
* USB
* Bluetooth
* Wifi
* Wifi-kill switch
* libgfxinit
* SATA
* Audio
* SD-card
* Ethernet
* Keyboard
* Fn-Keys
* Display brightness
* ACPI S3 resume
* Battery events
* CPU temperature reporting
* FAN managment
* Stress test stable
  * Youtube videos over Wifi
  * stress -c 2 -m 1 -d 1
  * glxgears

Change-Id: I0b1d04f00b5dbb38cf04333f2b345749b740a375
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39129
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2020-03-02 11:39:05 +00:00

2.5 KiB

Raw Blame History

Lenovo Sandy Bridge series

Flashing coreboot

+---------------------+--------------------+
| Type                | Value              |
+=====================+====================+
| Socketed flash      | no                 |
+---------------------+--------------------+
| Size                | 8 MiB              |
+---------------------+--------------------+
| In circuit flashing | Yes                |
+---------------------+--------------------+
| Package             | SOIC-8             |
+---------------------+--------------------+
| Write protection    | No                 |
+---------------------+--------------------+
| Dual BIOS feature   | No                 |
+---------------------+--------------------+
| Internal flashing   | Yes                |
+---------------------+--------------------+

Installation instructions

Update the EC firmware, as there's no support for EC updates in coreboot.
Do NOT accidently swap pins or power on the board while a SPI flasher is connected. It will destroy your device.
It's recommended to only flash the BIOS region. In that case you don't need to extract blobs from vendor firmware. If you want to flash the whole chip, you need blobs when building coreboot.
The shipped Flash layout allocates 3MiB to the BIOS region, which is the space usable by coreboot.
ROM chip size should be set to 8MiB.

Please also have a look at the [flashing tutorial]

Flash layout

There's one 8MiB flash which contains IFD, GBE, ME and BIOS regions. On Lenovo's UEFI the EC firmware update is placed at the start of the BIOS region. The update is then written into the EC once.

Reducing Intel Managment Engine firmware size

It is possible to reduce the Intel ME firmware size to free additional space for the bios region. This is usually refered to as cleaning the ME or stripping the ME. After reducing the Intel ME firmware size you must modify the original IFD and then write a full ROM using an external programmer. Have a look at the me_cleaner for more information.

Tests on Lenovo X220 showed no issues with a stripped ME firmware.

Modified flash layout:

The overall size of the gbe, me, ifd region is less than 128KiB, leaving the remaining space for the bios partition.

2.5 KiB Raw Blame History