% Binäre Blob Reduktions Richtlinie % Leah Rowe % 4 January 2022 (updated 15 November 2022)

Einleitung

Dieser Artikel beschreibt die Prinzipien die das Libreboot Projekt definieren. Für Informationen darüber wie diese Prinzipien in der Praxis angewendet werden, bitte lies diesen Artikel stattdessen: Software and hardware freedom status for each mainboard supported by Libreboot

Libreboot's Richtlinie ist für jeden Benutzer so viel Software Freiheit zu bieten wie möglich, auf jeglichem Bit von unterstützter Hardware, und so viel Hardware von Coreboot zu unterstützen wie möglich; was dies bedeutet ist, dass Du die Möglichkeit haben solltest, jeglichen Quelltext, jegliche Dokumentation oder jegliche andere Ressource die Libreboot zu dem machen was es ist, zu lesen, zu modifizieren und zu teilen. Einfach geasgt, Du solltest Kontrolle haben über deine eigene Computernutzung.

Das Ziel von Libreboot ist es genau dies zu ermöglichen, und möglichst vielen Benutzern zu helfen, mittels Automation der Konfiguration, Kompilierung und Installation von coreboot für technisch-unerfahrene Benutzer, und dies weiter zu vereinfachen für den durchschnittlichen Benutzer indem benutzerfreundliche Anleitungen für alles zur Verfügung gestellt werden. Grundsätzlich, Libreboot ist eine coreboot Distribution, ähnlich wie Alpine Linux eine Linux Distribution ist!

Der Zweck diese Dokuments ist, zu skizzieren wie dies erzielt wird, und wie das Projekt auf dieser Basis operiert. Dieses Dokument ist hauptsächlich über die Ideologie und ist daher (größtenteils) nicht-technisch; für technische Informationen schau in die Libreboot build system documentation.

Derzeitiger Projektrahmen

Das Libreboot Projekt ist besorgt um das was in den Haupt Boot Flash IC geht, aber es gibt andere Firmware Teile welche in Betracht gezogen werden sollten, wie erläutert im libreboot FAQ.

Die kritischsten hiervon sind:

Embedded controller firmware
HDD/SSD firmware
Intel Management Engine / AMD PSP firmware

Was ist ein binärer Blob?

Ein binärer Blob, in diesem Zusammenhang, ist jegliches Ausführbares für welches kein Quelltext existiert, welchen Du nicht in einer angemessenen Form lesen und modifizieren darfst. Per Definition sind all diese Blobs proprietärer Natur und sollten vermieden werden.

Bestimmte binäre Blobs sind ebenso problematisch, auf den meisten Coreboot Systemen, aber sie unterscheiden sich von Maschine zu Maschine. Lies mehr unter FAQ, oder auf dieser Seite wie wir mit diesen binären Blobs im Libreboot Projekt umgehen.

Für Informationen über die Intel Management Engine und AMD PSP, schau unter FAQ.

Blob reduction policy

Default configurations

Coreboot, upon which Libreboot is based, is mostly libre software but does require vendor files on some platforms. A most common example might be raminit (memory controller initialisation) or video framebuffer initialisation. The coreboot firmware uses certain vendor code for some of these tasks, on some mainboards, but some mainboards from coreboot can be initialised with 100% libre source code, which you can inspect, and compile for your use.

Libreboot deals with this situation in a strict and principled way. The nature of this is what you're about to read.

The libreboot project has the following policy:

If free software can be used, it should be used. For example, if VGA ROM initialization otherwise does a better job but coreboot has libre init code for a given graphics device, that code should be used in libreboot, when building a ROM image. Similarly, if memory controller initialization is possible with vendor code or libre code in coreboot, the libre code should be used in ROMs built by the Libreboot build system, and the vendor raminit code should not be used; however, if no libre init code is available for said raminit, it is permitted and Libreboot build system will use the vendor code.
Some nuance is to be observed: on some laptop or desktop configurations, it's common that there will be two graphics devices (for example, an nvidia and an intel chip, using nvidia optimus technology, on a laptop). It may be that one of them has libre init code in coreboot, but the other one does not. It's perfectly acceptable, and desirable, for libreboot to support both devices, and accomodate the required vendor code on the one that lacks native initialization.
An exception is made for CPU microcode updates: they are permitted, and in fact required as per libreboot policy. These updates fix CPU bugs, including security bugs, and since the CPU already has non-libre microcode burned into ROM anyway, the only choice is either x86 or broken x86. Thus, libreboot will only allow coreboot mainboard configurations where microcode updates are enabled, if available for the CPU on that mainboard. Releases after 20230423 will provide separate ROM images with microcode excluded, alongside the default ones that include microcode.
Intel Management Engine: in the libreboot documentation, words must be written to tell people how to neuter the ME, if possible on a given board. The me_cleaner program is very useful, and provides a much more secure ME configuration.
Vendor blobs should never be deleted, even if they are unused. In the coreboot project, a set of 3rdparty submodules are available, with vendor blobs for init tasks on many boards. These must all be included in libreboot releases, even if unused. That way, even if the Libreboot build system does not yet integrate support for a given board, someone who downloads libreboot can still make changes to their local version of the build system, if they wish, to provide a configuration for their hardware.

Generally speaking, common sense is applied. For example, an exception to the minimalization might be if vendor raminit and libre raminit are possible, but the libre one is so broken so as to be unusable. In that situation, the vendor one should be used instead, because otherwise the user might switch back to an otherwise fully proprietary system, instead of using coreboot (via libreboot). Some freedom is better than none.

Libreboot's pragmatic policies will inevitably result in more people becoming coreboot developers in the future, by acting as that crucial bridge between it and non-technical people who just need a bit of help to get started.

Configuration

The principles above should apply to default configurations. However, libreboot is to be configurable, allowing the user to do whatever they like.

It's natural that the user may want to create a setup that is less libre than the default one in libreboot. This is perfectly acceptable; freedom is superior, and should be encouraged, but the user's freedom to choose should also be respected, and accomodated.

In other words, do not lecture the user. Just try to help them with their problem! The goal of the libreboot project is simply to make coreboot more accessible for otherwise non-technical users.

FREEDOM CATALOG

A freedom status page should also be made available, educating people about the software freedom status on each machine supported by the Libreboot build system. Please read: Software and hardware freedom status for each mainboard supported by Libreboot.

It is desirable to see a world where all hardware and software is libre, under the same ideology as the Libreboot project. Hardware!?

Yes, hardware. RISC-V is a great example of a modern attempt at libre hardware, often called Open Source Hardware. It is a an ISA for the manufacture of a microprocessor. Many real-world implementations of it already exist, that can be used, and there will only be more.

Such hardware is still in its infancy. We should start a project that will catalog the status of various efforts, including at the hardware level (even the silicon level). Movements like OSHW and Right To Repair are extremely important, including to our own movement which otherwise will typically think less about hardware freedoms (even though it really, really should!)

One day, we will live in a world where anyone can get their own chips made, including CPUs but also every other type of IC. Efforts to make homemade chip fabrication a reality are now in their infancy, but such efforts do exist, for example, the work done by Sam Zeloof and the Libre Silicon project:

(Sam literally makes CPUs in his garage)

Why?

This next section previously existed in a less than diplomatic manner. It has been restored, as of August 2024, because the wisdom that it provides is important, yet being respectful of our friends in Massachussets is also a good thing to do, where feasible. This section was previously deleted, as a gesture of good will to those people, but it can't not be here, so without further ado:

Firstly, observe the following graphic:

Why does this policy page need to be written? Isn't it just describing basic common sense? The common sense that free software activism must demand all software to be free; why even talk about it?

This page has talked about Libreboot's blob reduction policy, but more context is needed. We need to talk about it, because there are many different interpretations for the exact same argument, depending on your point of view.

If you use a piece of hardware in Linux, and it works, you might see that it has free drivers and think nothing else. You will run free application software such as Firefox, Vim, KDE Plasma desktop, and everything is wonderful, right?

Where drivers and applications (and your operating system) are concerned, this is much clearer, because it's software that you're running on your main CPU, that you installed yourself. What of firmware?

Libreboot is not the only firmware that exists on your machine, when you have Libreboot. Look at these articles, which cover other firmwares:

You may ask: should the other firmwares be free too? The answer is yes, but it's complicated: it's not always practical to even study those firmwares. For example, there are so many webcams out there, so many SSDs, so many devices all doing the same thing, but implemented differently. Coreboot is already hard enough, and there are so many mainboards out there.

For example: every SSD has its own controller, and it has to do a lot of error correction at great speed, to mitigate the inherent unreliability of NAND flash. This firmware is highly specialised, and tailored to that SSD; not merely that SSD product line, but that SSD, because it often has to be tweaked per SSD; ditto SD cards, which fundamentally use the same technology. Would it be practical for something like Linux to provide firmware for absolutely every SSD? No. Absolutely not; and this is actually an example of where it makes more sense to bake the firmware into the hardware, rather than supply it as a firmware in Linux (even if the firmware is updateable, which it is on some SSDs).

Another example: your wireless card implements a software defined radio, to implement all of the various WiFi protocols, which is what your WiFi drivers make use of. The drivers themselves are also quite complicated. However, the same driver might be able to operate multiple wireless cards, if there is some standard interface (regardless of whether it's documented), that the same driver can use between all the cards, even if those cards are all very different; this is where firmware comes in.

Coreboot only covers the main boot firmware, but you will have other firmware running on your machine. It's simply a fact.

Historically, a lot of hardware has firmware baked into it, which does whatever it does on that piece of hardware (e.g. software defined radio on a wifi device, firmware implementing an AHCI interface for your SATA SSD).

In some cases, you will find that this firmware is not baked into the device. Instead, a firmware is provided in Linux, uploaded to the device at boot time, and this must be performed every time you boot or every time you plug in that device.

Having firmware in Linux is good. Proprietary software is also bad, so why is having more proprietary firmware in Linux good? Surely, free firmware would be better, but this firmware has never been free; typically, most firmware has been non-free, but baked into the hardware so you just didn't see it. We can demand that the vendors release source code, and we do; in some cases, we even succeed (for example ath9k_htc WiFi dongles have free firmware available in Linux).

The reason vendors put more firmware in Linux nowadays is it's cheaper. If the device itself has firmware baked in, then more money is spent on the EEPROM that stores it, and it makes research/development more expensive; having an easy software update mechanism allows bugs to be fixed more quickly, during development and post-release, thus reducing costs. This saves the industry billions, and it is actually of benefit to the free software community, because it makes reverse engineering easier, and it makes actually updating the firmware easier, so more proprietary software can actually be replaced with free software. If some standard interface exists, for the firmware, then that makes reverse engineering easier across many devices, instead of just one.

Hardware is also very complex, more so now than in the past; having the hardware be flexible, configured by firmware, makes it easier to work around defects in the hardware. For example, if a circuit for a new feature is quite buggy on a bit of hardware, but could be turned off without ill consequence, a firmware update might do exactly that.

The existence of such firmware also reminds more people of that fact, so more people are likely to demand free software. If the firmware is hidden in the hardware, fewer people are likely to raise a stink about it. We in the Libreboot project want all firmware to be free, and we've known of this problem for years.

Some people take what we call the head in the sand approach, where any and all software in Linux must be excluded; certain distros out there do this, and it is an entirely misguided approach. It is misguided, precisely because it tells people that compatible hardware is more free, when it isn't; more likely, any hardware that works (without firmware in Linux) likely just has that same firmware baked into it; in other words, hidden from the user. Hence the head in the sand approach - and this approach would result in far less hardware being supported.

Libreboot previously had its head in the sand, before November 2022. Since November 2022, Libreboot has been much more pragmatic, implementing the policy that you read now, instead of simply banning all proprietary firmware; the result is increased hardware support, and in practise many of the newer machines we support are still entirely free in coreboot (including memory controller initialisation), right up to Intel Haswell generation.

You are advised not to put your head in the sand. Better to see the world as it is, and here is the actual world as it is:

These firmwares are required. In some cases, hardware might have firmware baked in but provide an update mechanism, e.g. CPU microcode update mechanism. These firmware updates fix security bugs, reliability issues, and in some cases even safety issues (e.g. thermal safety on a CPU fixed by a microcode update).

Baking firmware into the device means that the firmware is less likely to be seen by the user, so fewer people are likely to raise a fuss about it; if the main boot firmware for example was baked into the PCH on your Intel system, completely non-replaceable or even inaccessible, fewer people would demand free boot firmware and a project like coreboot (and by extension Libreboot) may not even exist!

Such is the paradox of free firmware development. Libreboot previously took a much more hardline approach, banning absolutely all proprietary firmware whatsoever; the result was that far fewer machines could be supported. A more pragmatic policy, the one you've just read, was introduced in November 2022, in an effort to support more hardware and therefore increase the number of coreboot users; by extension, this will lead to more coreboot development, and more proprietary firmware being replaced with free software.

Facts are facts; how you handle them is where the magic happens, and Libreboot has made its choice. The result since November 2022 has indeed been more coreboot users, and a lot more hardware supported; more hardware has been ported to coreboot, that might not have even been ported in the first place, e.g. more Dell Latitude laptops are supported now (basically all of the IvyBridge and SandyBridge ones).

The four freedoms are absolute, but the road to freedom is never a straight line. Libreboot's policies are laser-focused on getting to that final goal, but without being dogmatic. By being flexible, while pushing for more firmware to be freed, more firmware is freed. It's as simple as that. We don't want proprietary software at all, but in order to have less of it, we have to have more - for now.

Let's take an extreme example: what if coreboot was entirely binary blobs for a given mainboard? Coreboot itself only initialises the hardware, and jumps to a payload in the flash; in this case, the payload (e.g. GNU GRUB) would still be free software. Surely, all free firmware would be better, but this is still an improvement over the original vendor firmware. The original vendor firmware will have non-free boot firmware and its analog of a coreboot payload (typically a UEFI implementation running various applications via DXEs) would be non-free. Coreboot does in fact do this on many newer Intel and AMD platforms, all of which Libreboot intends to accomodate in the future, and doing so would absolutely comply with this very policy that you are reading now, namely the Binary Blob Reduction Policy.

You can bet we'll tell everyone that Intel FSP is bad and should be replaced with free software, and we do; many Intel blobs have in fact been replaced with Free Software. For example, Libreboot previously provided Intel MRC which is a raminit blob, on Intel Haswell machines. Angel Pons reverse engineered the MRC and wrote native memory controller initialisation (raminit) on this platform, which Libreboot now uses instead of MRC.

This is a delicate balance, that a lot of projects get wrong - they will accept blobs, and not talk about them. In Libreboot, it's the exact opposite: we make sure you know about them, and tell you that they are bad, and we say that they should be fully replaced.

Unlike some in the community, we even advocate for free software in cases where the software can't actually be replaced. For example: the RP2040 Boot ROM is free software, with public source code:

https://github.com/raspberrypi/pico-bootrom-rp2040

This is the boot ROM source code for RP2040 devices such as Raspberry Pi Pico. It is a reprogrammable device, and we even use it as a cheap SPI flasher running pico-serprog. The main firmware is replaceable, but the boot ROM is read-only on this machine; there are some people would would not insist on free software at that level, despite being free software activists, because they would regard the boot ROM as "part of the hardware" - in Libreboot, we insist that all such software, including this, be free. Freedom merely to study the source code is still an important freedom, and someone might make a replica of the hardware at some point; if they do, that boot ROM source code is there for them to use, without having to re-implement it themselves. Isn't that great?

I hope that these examples might inspire some people to take more action in demanding free software everywhere, and to enlighten more people on the road to software freedom. The road Libreboot takes is the one less traveled, the one of pragmatism without compromise; we will not lose sight of our original goals, namely absolute computer user freedom.

The article will end here, because anything else would be more rambling.

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