Leah Rowe
c829b45c17
See: https://edc.intel.com/content/www/us/en/design/ipla/software-development-platforms/client/platforms/alder-lake-mobile-p/intel-600-series-chipset-family-on-package-platform-controller-hub-pch-datash/spi0-for-flash/ The rules described there are universal, and replicated elsewhere for many other platforms. The rules are simply: * Flash descriptor is one block size, e.g. 4KB * GbE is two block sizes, so if IfD is 4KB, GbE is 8KB Intel defines 16KB and 128KB GbE files in specs, pertaining to 8KB and 64KB block sizes respectively. The minimum size is 4KB blocksize, for 8KB GbE files which we already supported. On larger block sizes, the same 4KB parts are observed: a single 4KB IfD area at the start of the block, and: 4KB GbE part at the start of the GbE region, and: 4KB GbE part at the start of GbE region plus block size The empty space inbetween is padding, and we ignore it, except when running swap/copy commands. The nvmutil code has been modified, to create a 128KB buffer in memory instead of 8KB, for loading GbE files. Partsize is set to GbE file size divided by 2, and only the area of memory we need to use is mapped; for example, if we're loading a 8KB GbE file into memory, we only touch the first 8KB part of the buffer, or first 16KB for 128KB files. In practise, we almost never see GbE files with sizes higher than 8KB, but *we have seen it*, *AND NOW IT'S SUPPORTED!" Signed-off-by: Leah Rowe <leah@libreboot.org>
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 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), flashprog 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