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How to become the sole owner of your PC [pdf]

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Re: How to become the sole owner of your PC [pdf]

#81

Post by userbinator »

4ad wrote: post #72
13of40 wrote: post #64

Earlier quoted context omitted.

> they really intended it to be a backdoor-ish sort of thing Occam's razor says they really just sell a ton of CPUs to huge datacenters and wanted to solve the problem of having to have some tech go out and physically reset a machine when it misbehaves. If you've ever accidentally powered down a machine that's sitting in some lights-out facility in Northern Alabraska, this kind of technology is a godsend. Now I'm not…

No, Occam razor says that if all you you want to do is LOM, you put an embedded computer running Linux and ssh, connected only to to power and to the console, and nothing else, not a SPARC (?!?) core running proprietary code that does way, way more than just implement support for LOM, and which has access to all memory and CPU state.

That's exactly my thoughts --- the lack of much official information about ME beyond the fact that it exists and can do some stuff is troubling, plus the information gleaned from reverse-engineering it shows a much-obfuscated design. If they had documented it clearly and perhaps even released source for the software, we wouldn't be having this discussion.

http://recon.cx/2014/slides/Recon%202014%20Skochinsky.pdf

SPARC and Java(!) are present in this system. It gives a whole new meaning to the "3 billion devices run Java" advert...

Re: How to become the sole owner of your PC [pdf]

#84

Post by userbinator »

spash wrote: post #18
Samis2001 wrote: post #17

While I wait patiently for more open hardware designs to become more popular / actually used (Be it SPARC, RISC-V or something else), I wonder what AMD's equivalent functionality is like in comparison to this - I strongly doubt that no equivalent exists for AMD CPUs.

From https://libreboot.org/faq/#amd # Why is the latest AMD hardware unsupported in libreboot? It is extremely unlikely that any post-2013 AMD hardware will ever be supported in libreboot, due to severe security and freedom issues; so severe, that the libreboot project recommends avoiding all modern AMD hardware. If you have an AMD based system affected by the problems described below, then you should get rid of it a…

The PSP is an ARM core with TrustZone technology, built onto the main CPU die.

That sounds even worse than ME:

Intel Management Engine (ME) is a separate computing environment physically located in the (G)MCH chip.

Theoretically, if a third-party can figure out how to make a compatible MCH they can use Intel CPUs without ME, but that is impossible with AMD's design.

Then again, developing a compatible MCH would be nontrivial too --- the last truly "open" x86 bus interface was probably Socket 370 (still in use by VIA and others), and the later bus interfaces are such high speed that they require some very expensive signal analysers to even see the communications properly.

Re: How to become the sole owner of your PC [pdf]

#86

Post by 4ad »

userbinator wrote: post #81
4ad wrote: post #72

Earlier quoted context omitted.

No, Occam razor says that if all you you want to do is LOM, you put an embedded computer running Linux and ssh, connected only to to power and to the console, and nothing else, not a SPARC (?!?) core running proprietary code that does way, way more than just implement support for LOM, and which has access to all memory and CPU state.

That's exactly my thoughts --- the lack of much official information about ME beyond the fact that it exists and can do some stuff is troubling, plus the information gleaned from reverse-engineering it shows a much-obfuscated design. If they had documented it clearly and perhaps even released source for the software, we wouldn't be having this discussion. http://recon.cx/2014/slides/Recon%202014%20Skochinsky.pdf SPAR…

Pretty much. No engineer will decide to port Java to an embedded OS running on a foreign CPU when tasked with implementing a LOM system! The requirements are dictated by some other party. We don't know who the other party is, and we don't know what are the requirements. It's very normal to be skeptical of all this magic technology.

They even changed the CPU at some point. It used to be ARC, now it's SPARC. The LOM aspect of it didn't change. It worked just fine with ARC before. So why did it change?

There is no technical reason why implementing the LOM function is easier or better with one CPU compared with another. In fact, there's no technical reason why implementing anything is easier with one CPU or some other CPU. The new CPU seems even less power-efficient than their old one. The only reason why you'd want a particular CPU architecture is if you want to run some particular code for that particular CPU. And apparently running this secret code is so important, that it was worth the huge expense of porting all the other already-existing, already-working firmware they had before.

Re: How to become the sole owner of your PC [pdf]

#87

Post by Zardoz84 »

kryptiskt wrote: post #75
4ad wrote: post #72

Earlier quoted context omitted.

No, Occam razor says that if all you you want to do is LOM, you put an embedded computer running Linux and ssh, connected only to to power and to the console, and nothing else, not a SPARC (?!?) core running proprietary code that does way, way more than just implement support for LOM, and which has access to all memory and CPU state.

It's not a SPARC, it's an ARC. It's a very different processor.

ARC not was a simplified SPARC for CPU architecture teaching ? I had to build it on VHDL on my first year.

Re: How to become the sole owner of your PC [pdf]

#88

Post by lucb1e »

imtringued wrote: post #68
lucb1e wrote: post #54

Earlier quoted context omitted.

Yeah, really. It's relatively well known among free software enthusiasts. The trouble is, what do you do about it?

You stop using phones.

Yeah same with those, I'm quite aware, but I do enjoy the benefits of having wireless internet during the 1.5h commute by public transport every day.

Re: How to become the sole owner of your PC [pdf]

#89

Post by 4ad »

Zardoz84 wrote: post #87
kryptiskt wrote: post #75

Earlier quoted context omitted.

It's not a SPARC, it's an ARC. It's a very different processor.

ARC not was a simplified SPARC for CPU architecture teaching ? I had to build it on VHDL on my first year.

Well I have no idea how ARC came into existence, but looking at the ISA, it has nothing in common with SPARC (I write SPARC compilers for a living, so I know the ISA pretty well).

Re: How to become the sole owner of your PC [pdf]

#90

Post by aexaey »

4ad wrote: post #72
13of40 wrote: post #64

Earlier quoted context omitted.

> they really intended it to be a backdoor-ish sort of thing Occam's razor says they really just sell a ton of CPUs to huge datacenters and wanted to solve the problem of having to have some tech go out and physically reset a machine when it misbehaves. If you've ever accidentally powered down a machine that's sitting in some lights-out facility in Northern Alabraska, this kind of technology is a godsend. Now I'm not…

No, Occam razor says that if all you you want to do is LOM, you put an embedded computer running Linux and ssh, connected only to to power and to the console, and nothing else, not a SPARC (?!?) core running proprietary code that does way, way more than just implement support for LOM, and which has access to all memory and CPU state.

Completely agree with your sentiment. Just one small nit-pick: Intel doesn't use SPARC, but a much more obscure, less documented, and very proprietary ARC core [1, 2 & 3]. Ostensibly it was chosen due to having some excellent low-power modes.

[1] http://en.wikipedia.org/wiki/ARC_%28processor%29

[2] http://www.eetimes.com/document.asp?doc_id=1248611

[3] http://blog.invisiblethings.org/2015/10/27/x86_harmful.html

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