lbwww/site/docs/install/ivy_has_common.md

Well, if the blobs cannot be freely redistributed, then we can't provide them. So how do we handle that, in the context of Libreboot releases?

The solution

The answer is very simple: these blobs are NOT provided, at all! However, the very same logic used by the build system can be run standalone, to re-insert these binary blobs on release ROMs. The inject script detects what blobs are needed for your ROM image.

The script will detect what board you're inserting on, or you can manually tell it what board, and it will fetch them for you, inserting them, so that your board is ready to flash - flashing it without these required blobs may result in a brick.

Blob locations

During auto-download of blobs, they are saved to these locations within the Libreboot build system:

• ME firmware: blobs/*/me.bin - the * can be any given directory. Different ones will be used by given boards, but the directory name may not match the board target name.
• SMSC SCH5545 fan control firmware (for Dell T1650): blobs/t1650/sch5545ec.bin
• SMSC KBC1126 embedded controller firmware, on HP EliteBooks: ec/
• Intel MRC firmware, used for ram/peripheral init on Haswell machines such as thinkpad t440p/w541: mrc/

The above list refers to the non-redistributable blobs, and these are not directly included in releases. These are what blobutil auto-downloads. The me.bin files are produced by extracting them from vendor updates and neutering them with me_cleaner so that Intel ME is disabled during early boot.

Injecting Blobs into an Existing Rom

You must determine the correct board name, for your board, based on the list generated when running this command:

./build boot roms list

For example, t440pmrc_12mb corresponds to ThinkPad T440p with MRC firmware. Whereas t440plibremrc_12mb corresponds to T440p with libre MRC firmware. Another example: x230_12mb corresponds to Thinkpad X230.

In order to inject the necessary blobs into a rom image, run the script from the root of lbmk and point to the rom image.

If you only wish to flash a release rom then the process of injecting the necessary blobs is quite simple. Run the injection script pointing to the release archive you downloaded:

./update blobs inject /path/to/libreboot-20230319-18-g9f76c92_t440pmrc_12mb.tar.xz

The script can automatically detect the board as long as you do not change the file name. You can then find flash-ready ROMs in /bin/release/

Alternatively, you may patch only a single rom file, but you must supply the correct board target name as alluded to above. For example:

./update blobs inject -r x230_libreboot.rom -b x230_12mb

Optionally, you can use this script to modify the mac address of the rom with the -m flag. For example:

./update blobs inject -r x230_libreboot.rom -b x230_12mb -m 00:f6:f0:40:71:fd

Check that the blobs were inserted

You must ensure that the blobs were inserted.

Some examples of how to do that in lbmk:

./build module cbutils

Now you find cbutitls/default, which is a directory containing cbfstool and ifdtool. Do this on your ROM image (libreboot.rom in the example below):

./cbutils/default/cbfstool libreboot.rom print

You should check that the blobs were inserted in cbfs, if needed; for example, EC firmware or MRC firmware.

Next:

./cbutils/default/ifdtool -x libreboot.rom

This creates several .bin files, one of which says me in it (Intel ME). Run hexdump on it:

hexdump flashregion_2_intel_me.bin

Check the output. If it's all 0xFF (all ones) or otherwise isn't a bunch of code, then the Intel ME firmware wasn't inserted.

You'll note the small size of the Intel ME, e.g. 84KB on sandybridge platforms. This is because blobutil automatically neuters it, disabling it during early boot. This is done using me_cleaner, which lbmk imports.

Errata

NOTE: Haswell machines come with mrc.bin or without, depending on the ROM image configuration. These ROM configs have mrc.bin: t440pmrc_12mb and w541mrc_12mb. These ROM configs have libre MRC: t440p_12mb and w541_12mb - it is critical that you choose the right one, when using the -b flag in the blobutil inject command. For example, if you used -b t440p_12mb on a ROM image that actually corresponds to t440pmrc_12mb, then the required mrc.bin file would not be added and that ROM would not boot when flashed.

NOTE: In the Libreboot 20230319 src archive or git tag, the blobutil insert method is broken on Haswell configs that need mrc.bin, because it does not insert mrc.bin at the correct offset. This was fixed in revisions after the release, and will be available in the next release after that. Read the Libreboot 20230319 update announcement for more information.

NOTE: the MAC changer makes use of nvmutil, which you can read more about in the nvmutil documentation.

**WARNING: This is broken in Libreboot 20221214's src archive. It fails when attempting to use cbfstool, due to a faulty check in a script. This is fixed in recent Libreboot releases or revisions. The fix is as follows:

Edit line 137 in resources/scripts/blobs/inject. The line in 20221214 says this:

make -C cd coreboot/default/util/cbfstool || Fail 'could not build ifdtool'

Modify it to say this:

make -C coreboot/default/util/cbfstool || Fail 'could not build cbfstool'

ALSO:

When generating a MAC address, the same script tries to build nvmutil from /util/nvmutil, in Libreboot 20221214. This was discovered on 10 January 2023, based on user report on IRC. Fix it like so (already fixed, in latest Libreboot from Git):

Line 30, it says:

make -C /util/nvmutil || Fail 'failed to build nvmutil'

Change it to say:

make -C util/nvmutil || Fail 'failed to build nvmutil'

Until this is edited accordingly, the inject script will exit with non-zero status, and no blobs will be injected.

This has been fixed, following the Libreboot 20221214 release, but you must apply this fix yourself, if using that release.