# Lenovo Ivy Bridge series

This information is valid for all supported models, except T430s, [T431s](t431s.md) and [X230s](x230s.md).

## Flashing coreboot
```{eval-rst}
+---------------------+--------------------------------+
| Type                | Value                          |
+=====================+================================+
| Socketed flash      | no                             |
+---------------------+--------------------------------+
| Size                | 8 MiB + 4MiB                   |
+---------------------+--------------------------------+
| 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** accidentally swap pins or power on the board while a SPI flasher
  is connected. It will permanently brick 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 *Flash layout* shows that by default 7MiB of space are available for
  the use with coreboot.
* In that case you only want to use a part of the BIOS region that must not
  exceed 4MiB in size, which means CONFIG_CBFS_SIZE must be smaller than 4MiB.
* ROM chip size should be set to 12MiB.

```{eval-rst}
Please also have a look at :doc:`../../tutorial/flashing_firmware/index`.
```

## Splitting the coreboot.rom

To split the coreboot.rom into two images (one for the 8MiB and one for the
4 MiB flash IC), run the following commands:

```bash
dd of=top.rom bs=1M if=build/coreboot.rom skip=8
dd of=bottom.rom bs=1M if=build/coreboot.rom count=8
```

That gives one ROM for each flash IC, where *top.rom* is the upper part of the
flash image, that resides on the 4 MiB flash and *bottom.rom* is the lower part
of the flash image, that resides on the 8 MiB flash.

## Dumping a full ROM

If you flash externally you need to read both flash chips to get two images
(one for the 8MiB and one for the 4 MiB flash IC), and then run the following
command to concatenate the files:

```bash
cat bottom.rom top.rom > firmware.rom
```

## Flash layout
There's one 8MiB and one 4 MiB flash which contains IFD, GBE, ME and
BIOS region. These two flash ICs appear as a single 12MiB when flashing
internally.
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.

![][fl]

[fl]: flashlayout_Ivy_Bridge.svg

## Reducing Intel Management Engine firmware size

It is possible to reduce the Intel ME firmware size to free additional
space for the `bios` region. This is usually referred to as *cleaning the ME* or
*stripping the ME*.
After reducing the Intel ME firmware size you must modify the original IFD,
[split the resulting coreboot ROM](#splitting-the-corebootrom) and then write
each ROM using an [external programmer].
Have a look at [me_cleaner] for more information.

Tests on Lenovo W530 showed no issues with a stripped and shrunken ME firmware.


[me_cleaner]: ../../northbridge/intel/sandybridge/me_cleaner.md
[external programmer]: ../../tutorial/flashing_firmware/index.md