On the 16KB and 128KB files, we still only need to operate on 4KB at the start of each block, where the block size is larger than 4KB. The reason we deal with the entire 4KB block is because the nvm words (in the 128 byte section) can define an extended nvm area anywhere after 128 bytes, within the 128 byte block. We could systematically read where that is being handled, and handle it; we could then allocate less memory, and read/write fewer bytes, but many block devices like SSDs and flash drives have at least a 4KB erase block anyway, so it's kinda pointless. saving memory would be nice, but I don't really want to bloat the code. This is a nice easy optimisation, to avoid wasting an additional 8KB of memory when handling 16KB files, and additional 120KB if handling 128KB files, since nf is what determines how much memory will be allocated. the alternative would be to use an mmap, and then we could reasonably handle the idea above for only writing, surgically, what we need: nvm words and extended nvm words. 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