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-rw-r--r--Documentation/mainboard/lenovo/Sandy_Bridge_series.md27
-rw-r--r--Documentation/mainboard/lenovo/flashlayout_Sandy_Bridge_stripped_me.svg74
-rw-r--r--Documentation/northbridge/intel/sandybridge/me_cleaner.md66
3 files changed, 163 insertions, 4 deletions
diff --git a/Documentation/mainboard/lenovo/Sandy_Bridge_series.md b/Documentation/mainboard/lenovo/Sandy_Bridge_series.md
index 0b833f5cc8..dbbbbeef30 100644
--- a/Documentation/mainboard/lenovo/Sandy_Bridge_series.md
+++ b/Documentation/mainboard/lenovo/Sandy_Bridge_series.md
@@ -33,9 +33,7 @@
usable by coreboot.
* ROM chip size should be set to 8MiB.
-```eval_rst
-Please also have a look at :doc:`../../flash_tutorial/index`.
-```
+Please also have a look at the [flashing tutorial]
## Flash layout
There's one 8MiB flash which contains IFD, GBE, ME and BIOS regions.
@@ -46,3 +44,26 @@ region. The update is then written into the EC once.
[fl]: flashlayout_Sandy_Bridge.svg
+## 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:**
+
+![][fl2]
+
+[fl2]: flashlayout_Sandy_Bridge_stripped_me.svg
+
+The overall size of the `gbe`, `me,` `ifd` region is less than 128KiB, leaving
+the remaining space for the `bios` partition.
+
+
+[me_cleaner]: ../../northbridge/intel/sandybridge/me_cleaner.md
+[external programmer]: ../../flash_tutorial/index.md
diff --git a/Documentation/mainboard/lenovo/flashlayout_Sandy_Bridge_stripped_me.svg b/Documentation/mainboard/lenovo/flashlayout_Sandy_Bridge_stripped_me.svg
new file mode 100644
index 0000000000..d8d8213d12
--- /dev/null
+++ b/Documentation/mainboard/lenovo/flashlayout_Sandy_Bridge_stripped_me.svg
@@ -0,0 +1,74 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/PR-SVG-20010719/DTD/svg10.dtd">
+<svg width="9cm" height="8cm" viewBox="268 -156 168 158" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+ <g>
+ <g>
+ <g>
+ <rect style="fill: #ffffff" x="307.888" y="-152.131" width="49.1438" height="30.4667"/>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #ffffff" x="307.888" y="-152.131" width="49.1438" height="30.4667"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #ffffff" x="307.888" y="-152.131" width="49.1438" height="30.4667"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #000000" x="307.888" y="-152.131" width="49.1438" height="30.4667"/>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:middle;font-family:sans-serif;font-style:normal;font-weight:normal" x="332.46" y="-134.831">
+ <tspan x="332.46" y="-134.831">IFD</tspan>
+ </text>
+ </g>
+ <g>
+ <g>
+ <rect style="fill: #ffffff" x="307.934" y="-56.9106" width="49.1438" height="56.1492"/>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 0.02; stroke: #ffffff" x="307.934" y="-56.9106" width="49.1438" height="56.1492"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 0.02; stroke: #ffffff" x="307.934" y="-56.9106" width="49.1438" height="56.1492"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #000000" x="308.096" y="-57.559" width="49.1438" height="57.2839"/>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:middle;font-family:sans-serif;font-style:normal;font-weight:normal" x="332.182" y="-24.0245">
+ <tspan x="332.182" y="-24.0245">BIOS</tspan>
+ </text>
+ <g>
+ <g>
+ <g>
+ <rect style="fill: #ffffff" x="308" y="-121.59" width="49.1438" height="30.4667"/>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #ffffff" x="308" y="-121.59" width="49.1438" height="30.4667"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #ffffff" x="308" y="-121.59" width="49.1438" height="30.4667"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #000000" x="308" y="-121.59" width="49.1438" height="30.4667"/>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:middle;font-family:sans-serif;font-style:normal;font-weight:normal" x="332.572" y="-104.29">
+ <tspan x="332.572" y="-104.29">GBE</tspan>
+ </text>
+ </g>
+ <text font-size="7.15705" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="268.961" y="-148.674">
+ <tspan x="268.961" y="-148.674">0x000000</tspan>
+ </text>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="269.152" y="-120.399">
+ <tspan x="269.152" y="-120.399">0x001000</tspan>
+ </text>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="269.155" y="-90.6472">
+ <tspan x="269.155" y="-90.6472">0x003000</tspan>
+ </text>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="269.461" y="-56.4289">
+ <tspan x="269.461" y="-56.4289">0x020000</tspan>
+ </text>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="270.008" y="0.198407">
+ <tspan x="270.008" y="0.198407">0x800000</tspan>
+ </text>
+ <path style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" d="M 380.877 -151.013 C 401.876,-151.013 379.377,-73.513 400.627,-72.513"/>
+ <path style="fill: none; fill-opacity:0; stroke-width: 1; stroke: #000000" d="M 381.377 -0.763268 C 395.238,-0.763268 387.016,-72.763 400.877,-72.763"/>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:start;font-family:sans-serif;font-style:normal;font-weight:normal" x="406.127" y="-68.513">
+ <tspan x="406.127" y="-68.513">Flash #0</tspan>
+ </text>
+ <g>
+ <g>
+ <g>
+ <rect style="fill: #ffffff" x="308.189" y="-90.5898" width="49.1438" height="33.4161"/>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #ffffff" x="308.189" y="-90.5898" width="49.1438" height="33.4161"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #ffffff" x="308.189" y="-90.5898" width="49.1438" height="33.4161"/>
+ </g>
+ <rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke: #000000" x="308.189" y="-90.5898" width="49.1438" height="32.8215"/>
+ <text font-size="6.77323" style="fill: #000000;text-anchor:middle;font-family:sans-serif;font-style:normal;font-weight:normal" x="331.572" y="-70.23">
+ <tspan x="331.572" y="-70.23">ME</tspan>
+ </text>
+ </g>
+</svg>
diff --git a/Documentation/northbridge/intel/sandybridge/me_cleaner.md b/Documentation/northbridge/intel/sandybridge/me_cleaner.md
index 1086e7e091..b457dcdd3c 100644
--- a/Documentation/northbridge/intel/sandybridge/me_cleaner.md
+++ b/Documentation/northbridge/intel/sandybridge/me_cleaner.md
@@ -5,7 +5,7 @@ from the ME firmware partition. In this state the ME errors out and doesn't
operate any more.
**Using a 'cleaned' ME partition may lead to issues and its use should be
-carefully evaulated.**
+carefully evaluated.**
## Observations with 'cleaned' ME
@@ -18,3 +18,67 @@ carefully evaulated.**
Always test with unmodified IFD and ME section before reporting bugs to the
coreboot project.
+
+## Tutorial reducing the Intel ME firmware size
+
+By default the cleaned ME firmware will still occupy the same space in
+the firmware image. It's possible to change the firmware partition layout
+and reclaim the space for the use by coreboot.
+With the reduced Intel ME firmware the `ifd`, `gbe` and `me` regions require
+less than 128 KiB of space in the ROM, which leaves the remaining for the
+`bios` region.
+
+This tutorial will guide you through the steps necessary.
+
+### 1. Obtain a full ROM
+
+You need a full and working ROM with a full Intel ME firmware.
+
+### 2. Running me_cleaner
+
+You need to run the *me_cleaner* on a full ROM, here called `fulldump.rom`:
+The full ROM contains:
+* IFD
+* fully working Intel ME
+* GbE (optional)
+* BIOS (any firmware)
+
+Running the command will generate two new files:
+```console
+./util/me_cleaner/me_cleaner.py -D patched_desciptor.bin -M stripped_me.bin fulldump.rom -t -r -S
+```
+
+The generated files are:
+* a patched IFD called `patched_desciptor.bin`
+* stripped Intel ME called `stripped_me.bin`
+
+The patched IFD has the *AltMeDisable* bit set and a modified flash layout.
+
+
+*Note:* coreboot allows to select `CONFIG_ME_CLEANER` as part of the
+build-process, but that doesn't rework the flash layout, it only removes
+files from ME and sets the *AltMeDisable*-bit.
+
+### 3. Build coreboot
+
+1. Now include the two new files from the previous step into coreboot's
+ build system.
+2. Make sure to also increase the CBFS size
+ * 0x7E0000 for a 8MiB ROM
+ * 0xBE0000 for a 12MiB ROM
+ * 0xFE0000 for a 16MiB ROM
+3. Make sure to **not** enable me_cleaner in Kconfig again as
+ you have already run it
+
+### 4. Flashing the ROM
+
+As you have modified the layout you need to write the **full ROM** to flash
+using an [external programmer].
+Make sure to include all partitions into the ROM:
+* IFD
+* EC (might be unused)
+* GbE (might be unused)
+* ME
+* BIOS
+
+[external programmer]: ../../../flash_tutorial/index.md