401c0882aa
This is of Broadwell platform, one generation above Haswell. Of note: this uses HP Sure Start. Although the flash is 16MB, our CBFS section (and IFD configuration) assumes 12MB flash, so the final 4MB will be left unflashed on installation, after blanking the private flash. The coreboot documents have more information about this. Some minor design changes in lbmk were made, to accomodate this port: Support for extracting refcode binaries added (pulled from Google recovery images). The refcode file is an ELF that initialises the MRC and the PCH. It is also responsible for enabling or disabling the Intel GbE device, where Google does not enable it, but lbmk modifies it per the instructions on the coreboot documentation, so as to enable Intel GbE. Google's recovery image stores the refcode as a stage file, but coreboot changed the format (for CBFS files) after 4.13 so coreboot 4.13's cbfstool is used to extract refcode. This realisation made me also change the script logic to use a cbfstool and ifdtool version matching the coreboot tree, for all parts of lbmk, whereas lbmk previously used only the default tree for cbfstool/ifdtool, on insertion and deletion of vendor files - it was 81dc20e744 that broke extraction of refcode on google's recovery images, where google used an older version of cbfstool to insert the files in their coreboot ROMs. A further backported patch has been added, copying coreboot revision f22f408956 which is a build fix from Nico Huber. Iru Cai submitted an ACPI bugfix after the revision lbmk currently uses, for coreboot/default, and this fix is needed for rebooting to work on Linux 6.1 or higher. This patch has been backported to lbmk, while it still uses the same October 2023 revision of coreboot. Broadwell MRC is inserted at the same offset as Haswell, so I didn't need to tweak that. Signed-off-by: Leah Rowe <leah@libreboot.org> |
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README.md
Libreboot
Find libreboot documentation at https://libreboot.org/
The libreboot
project provides
libre boot
firmware that initializes the hardware (e.g. memory controller, CPU,
peripherals) on specific Intel/AMD x86 and ARM targets, which
then starts a bootloader for your operating system. Linux/BSD are
well-supported. It replaces proprietary BIOS/UEFI firmware. Help is available
via #libreboot IRC
on Libera IRC.
Why use Libreboot?
Why should you use libreboot?
Libreboot gives you freedoms that you otherwise can't get with most other boot firmware. It's extremely powerful and configurable for many use cases.
You have rights. The right to privacy, freedom of thought, freedom of speech and the right to read. In this context, Libreboot gives you these rights. Your freedom matters. Right to repair matters. Many people use proprietary (non-libre) boot firmware, even if they use a libre OS. Proprietary firmware often contains backdoors (more info on the FAQ), and it and can be buggy. The libreboot project was founded in December 2013, with the express purpose of making coreboot firmware accessible for non-technical users.
The libreboot
project uses coreboot for hardware
initialisation.
Coreboot is notoriously difficult to install for most non-technical users; it
handles only basic initialization and jumps to a separate
payload program (e.g.
GRUB,
Tianocore), which must also be configured.
The libreboot software solves this problem; it is a coreboot distribution with
an automated build system (named lbmk) that builds complete ROM images, for
more robust installation. Documentation is provided.
How does Libreboot differ from coreboot?
In the same way that Debian is a GNU+Linux distribution, libreboot
is
a coreboot distribution. If you want to build a ROM image from scratch, you
otherwise have to perform expert-level configuration of coreboot, GRUB and
whatever other software you need, to prepare the ROM image. With libreboot,
you can literally download from Git or a source archive, and run make
, and it
will build entire ROM images. An automated build system, named lbmk
(Libreboot MaKe), builds these ROM images automatically, without any user input
or intervention required. Configuration has already been performed in advance.
If you were to build regular coreboot, without using libreboot's automated build system, it would require a lot more intervention and decent technical knowledge to produce a working configuration.
Regular binary releases of libreboot
provide these
ROM images pre-compiled, and you can simply install them, with no special
knowledge or skill except the ability to follow installation instructions
and run commands BSD/Linux.
Project goals
- Support as much hardware as possible! Libreboot aims to eventually have maintainers for every board supported by coreboot, at every point in time.
- Make coreboot easy to use. Coreboot is notoriously difficult to install, due to an overall lack of user-focused documentation and support. Most people will simply give up before attempting to install coreboot. Libreboot's automated build system and user-friendly installation instructions solves this problem.
Libreboot attempts to bridge this divide by providing a build system automating much of the coreboot image creation and customization. Secondly, the project produces documentation aimed at non-technical users. Thirdly, the project attempts to provide excellent user support via IRC.
Libreboot already comes with a payload (GRUB), flashrom and other needed parts. Everything is fully integrated, in a way where most of the complicated steps that are otherwise required, are instead done for the user in advance.
You can download ROM images for your libreboot system and install them without having to build anything from source. If, however, you are interested in building your own image, the build system makes it relatively easy to do so.
Not a coreboot fork!
Libreboot is not a fork of coreboot. Every so often, the project re-bases on the latest version of coreboot, with the number of custom patches in use minimized. Tested, stable (static) releases are then provided in Libreboot, based on specific coreboot revisions.
How to help
You can check bugs listed on the bug tracker.
If you spot a bug and have a fix, the website has instructions for how to send patches, and you can also report it. Also, this entire website is written in Markdown and hosted in a separate repository where you can send patches.
Any and all development discussion and user support are all done on the IRC channel. More information is on https://libreboot.org/contact.html.
LICENSE FOR THIS README
It's just a README file. This README file is released under the terms of the Creative Commons Zero license, version 1.0 of the license, which you can read here:
https://creativecommons.org/publicdomain/zero/1.0/legalcode.txt