bedc6b8f65
See, coreboot bug report: https://ticket.coreboot.org/issues/590 We hadn't noticed this for quite a while, since we always just booted with iomem=relaxed when needing to run cbmem, since in practise it was always combined with other tasks that require access to lower memory. GRUB currently matches coreboot's own mmap for cbmem, but for example SeaBIOS marks cbmem as E820 reserved. Therefore, this change replicates the SeaBIOS behaviour. Without this patch, Linux needs to boot with iomem=relaxed for cbmem access, for example when running ./cbmem -1 With this patch, cbmem is now accessible regardless. This patch also prevents Linux from overwriting parts of CBMEM. Thanks go to Paul Menzel, who wrote this GRUB patch. Thanks also go to Nicholas Chin, who provided testing, all the way from Coreboot 25.03 back to Coreboot 4.20. It seems that this is just something the payloads have to handle. This means that both SeaBIOS and GRUB no longer have this bug, in Libreboot; now what remains is to replicate the test with our U-Boot payload. Signed-off-by: Leah Rowe <leah@libreboot.org>
Libreboot
Documentation: libreboot.org
Support: #libreboot on
Libera IRC
Libreboot provides libre boot firmware on supported motherboards. It replaces proprietary vendor BIOS/UEFI implementations, by
- Using coreboot to initialize the hardware (e.g. memory controller, CPU, etc.) while minimizing unwanted functionality (e.g. backdoors such as the Intel Management Engine)
- ... which runs a payload such as SeaBIOS, GRUB, or U-Boot
- ... which loads your operating system's boot loader (BSD and Linux-based systems are supported).
Why use Libreboot, and what is coreboot?
A lot of users who use libre operating systems still use proprietary boot firmware, which often contain backdoors and bugs, hampering user freedom and right to repair.
coreboot provides libre boot firmware by initializing the hardware then running a payload. However, coreboot is notoriously difficult to configure and install for most non-technical users, requiring detailed technical knowledge of hardware.
Libreboot solves this by being a coreboot distribution (in the same way that Alpine Linux is a Linux distribution). It provides a fully automated build system that downloads and compiles pre-configured ROM images for supported motherboards, so end-users could easily fetch images to flash onto their devices.
Libreboot also produces documentation aimed at non-technical users and excellent user support via IRC.
Contribute
You can check bugs listed on the bug tracker.
You may use Codeberg pull requests to send patches with bug fixes or other improvements. This repository hosts the code for the main build system. The website lives in a separate repository.
Development is also done on the IRC channel.
License for this README
It's just a README file. It is released under Creative Commons Zero, version 1.0.