Librem 14's ME disabled but not neutralized

Not quite true, in the last couple of years there was quite detailed dissection of psp. The problem with psp is just that it’s fully signed so you cannot tamper with it (eg neutralize) as it would change signature. But you can still read it for offline analysis and tamper with runtime.


just disabled

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Okey’s who’s gonna bet with me, that I recieve one ping packet, and that management engine from intel is going to rebounce to main loop again?

Network card is from intel? How do you want to disable it?

Abandon intel developement while it’s time, and go workstation AMD processors.
Or ARM based notebook.

Since you can’t disable it and you can’t trust it … you don’t connect it i.e. no network cable connected to the wired network usable via the humunculus CPU (aka the Intel ME), or indeed not even connected internally. Not much is exfiltrated via ethernet when it’s not connected. (Probably different on the L14 c.f. the L13 and L15 but the idea is the same.)

The built-in WiFi in more recent Intel CPUs is more of a worry, albeit not quite a 100% problem yet.

Abandon x86. At the current time, neither of them allows you to build a fully satisfactory computer.


abandon SHIP !!! what ? abandon x86 ? what madness is this ?

I just got a mini desktop ( not a NUC ) with an AMD Ryzen 5 cpu and 16gb ram. What qualifies as a fully satisfactory computer?

Ryzen has the PSP, which functions like the Intel ME, but it can’t be disabled, so it is actually worse than the ME from our perspective.

It can run on 100% free/open source software, like the RaptorCS computers using POWER9 processors. The MNT Reform is pretty close, but it requires a small blob for the DDR timing. Olimex and Pine64 also sell some models that are close to the ideal.

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What a downer. Just when you think you’re starting to get free. It has Mint 20.1 Cinnamon on it. Does that help?

Forgot to ask but what is the PSP?

Like this one Amos?

So, POWER9 processors don’t have backdoors, like Intel ME and AMD PSP?


POWER9 processors don’t have anything like the ME and PSP, but a lot of software hasn’t been compiled for the POWER ISA architecture. Don’t expect to have an up-to-date web browser. I might consider buying a RaptorCS Talos II system for a server, but I don’t think I’d consider it for a personal computer. Honestly, the MNT Reform, OLIMEX TERES I and PINE64 PineBook Pro all look like better choices for most people, and they all publish their schematics, but they are underpowered compared to a standard x86 laptop.


maybe so but even if that AMD APU of yours has the PSP enabled it still has out-of-the-box support for the linux-kernel-amd-iGPU-driver (NOT libre and GNU yet but still open-source enough to just-work)

imo if you are running a GNU/Linux distribution that has support for that APU (debian+non-free/ubuntu/mint/popOS/arch/gentoo/etc.) it’s still better than any M$0S variant.

To be fair, we don’t know that the ME / PSP is a backdoor.

The failure to be fully satisfactory is that there is no way of knowing. It might be a backdoor. It might not be.

You can’t change the code that runs on the homunculus CPU.
You can’t fully disable it.
The homunculus CPU has all-powerful control over the main CPUs, completely bypassing the operating system.
It has network access.

(What’s not to hate? :wink:)

Whether it is a backdoor, I don’t know, but it has good attributes for being a backdoor even if it is not intentionally a backdoor.

Security flaws have been found in the homunculus CPU and that is a very dangerous place to have a security flaw.


Sorry but I’ve got another stupid question. What is a “homunculus” CPU ?


I would like to hear that to. There is a kind of figure, sculpture or statue in medicine. It map the size of parts of the body / organs to the size the corresponding organ takes in brain. Example: the lips are represented by relative big parts of the brain compared to other organs. So the lips of the homunculus sculpture are pretty big. This results in unordinary proportions of organs of the homunculus and the sculpture does look a bit scary. I don’t know where the word has its origin. Probably Greece or Latin.

Wikipedia says it means something like little human. Humanly / humanlet. They talk of an artificial human. It’s used in different contexts.

In relation to ME / PSP it is an interesting philosophical usage. An artificial little processor? Why do we need them if we already have processors (even if they are also artificial).

Opening paragraph of:

Intel’s ME and AMD’s PSP are both examples of a homunculus CPU.

A nasty little miniature CPU that is sucking the security life out of the main CPU.

Well that’s great. I can’t afford and wouldn’t spend the kind of money the Raptor Talos II commands unless I win Powerball or find a briefcase full of new $100 bills.
They are quite the machine though. Linus’s personal computer is pretty cool too. Little pricey but very cool.