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Re:I Love Arch, but GNU Guix Is My New Distro by fsflover on Saturday November 20, 2021 @09:53AM (#29288576)
I do not trust my CPU provider. Where do I find an alternative based exclusively on free software?
Re:I Love Arch, but GNU Guix Is My New Distro by marcan_42 on Saturday November 20, 2021 @10:26PM (#29293941)
If you do not trust your CPU provider, your only option is a design that assumes an adversarial manufacturer. The only credible design I've seen for this scenario is Precursor, which works because generic backdoors for FPGAs (i.e. those that work with arbitrary randomized designs) are arguably impractical, since you'd need a huge amount of compute power to attempt to analyze the design and figure out how to backdoor it. It's likely even an unsolvable problem in the general case.

https://www.crowdsupply.com/sutajio-kosagi/precursor

Of course, then you get a RISC-V running at 100MHz. If you want something faster, you need to trust your CPU provider. There's no way around that; silicon is not end-user introspectable.

Re:I Love Arch, but GNU Guix Is My New Distro by marcodiego on Saturday November 20, 2021 @10:18AM (#29288813)
Re:I Love Arch, but GNU Guix Is My New Distro by marcan_42 on Saturday November 20, 2021 @10:19PM (#29293906)
Every single laptop in the RYF list includes proprietary unauditable microcode. So do many of the other products there, e.g. that Bluetooth dongle which probably has about half a megabyte of proprietary firmware.
Re:I Love Arch, but GNU Guix Is My New Distro by nix23 on Saturday November 20, 2021 @10:17AM (#29288798)
Re:I Love Arch, but GNU Guix Is My New Distro by marcan_42 on Saturday November 20, 2021 @10:29PM (#29293967)
There is no reason to trust IBM not to include a silicon backdoor in POWER9 more than Intel not to include a silicon or microcode backdoor in their x86 chips. TALOS is a lot freer than most designs, but you still need to trust every manufacturer whose silicon went into that motherboard.
Re:I Love Arch, but GNU Guix Is My New Distro by nix23 on Sunday November 21, 2021 @06:10AM (#29295481)
>There is no reason to trust IBM not to include a silicon backdoor

Yeah ok now we are in the religion side of things, since you cannot check the silicon...well i stop here, not worth my time.

BTW: The power microcode is opensource.

Re:I Love Arch, but GNU Guix Is My New Distro by marcan_42 on Monday November 22, 2021 @12:23AM (#29303058)
You can backdoor silicon just as well as you can backdoor software or microcode. Why do you only care about trusting the latter?
Re:I Love Arch, but GNU Guix Is My New Distro by fsflover on Monday November 22, 2021 @10:00AM (#29306956)
Because the perfect is the enemy of the good: https://news.ycombinator.com/item?id=27897975.
Re:I Love Arch, but GNU Guix Is My New Distro by nix23 on Monday November 22, 2021 @03:33AM (#29304151)
>>since you cannot check the silicon...

READ.

The microcode is opensource..

Re:I Love Arch, but GNU Guix Is My New Distro by marcan_42 on Monday November 22, 2021 @09:38AM (#29306704)
The silicon - the rest of the logic that makes the CPU - isn't. There's more to CPUs than microcode. Besides, how can you audit that the open source microcode is what the manufacturer actually put into the CPU? Microcode is usually ROM-based with only runtime patches.

Open source microcode does not change the fact that you need to trust the CPU manufacturer not to backdoor your CPU. There is literally no way around that that does not involve using FPGAs and restricting yourself to 100MHz CPUs.

By the way, I googled POWER9 microcode and was not able to find any source or reference to it. The source code for the firmware running on various auxiliary cores is open source. However, the CPU cores do contain microcode for executing more complex instructions, and I am not finding any reference to this being open source.

Re:I Love Arch, but GNU Guix Is My New Distro by nix23 on Monday November 22, 2021 @03:46PM (#29311405)
I understand that you have problems reading so i repeat it for you the third time:

>>>since you cannot check the silicon...

And since you have problems using google too:

https://www.sbir.gov/node/1620879

>>A small business has already shown that a completely open source solution (to include CPU firmware, CPU Microcode, Baseboard Management Controller (BMC), BIOS boot code, power management, etc.) based on a high performance CPU is possible.

Imagine who that "small business" is?

Re:I Love Arch, but GNU Guix Is My New Distro by marcan_42 on Monday November 22, 2021 @10:29PM (#29314300)
Where's the link to the source?

FYI, IBM loves to use the term "microcode" to include side CPU firmware and such. This is different from Intel "microcode" which strictly refers to the instruction dispatch part. Is the instruction dispatch microcode in POWER9 open source or not?

None of these are it: https://wiki.raptorcs.com/wiki/OpenPOWER_Firmware

Re:I Love Arch, but GNU Guix Is My New Distro by nix23 on Tuesday November 23, 2021 @10:43AM (#29319113)
https://git.raptorcs.com/git/

>>CPU Internal Firmware

>>CPU External Firmware

Re:I Love Arch, but GNU Guix Is My New Distro by marcan_42 on Tuesday November 23, 2021 @12:39PM (#29320668)
SBE, OCC, HCODE. Those are from the list I linked. None of them are the instruction dispatch microcode.

Maybe it's time for you to have the realization that POWER9 has proprietary microcode just like Intel. At least it seems they probably have less of it, and they do vaguely document it in the CPU manual (they have micro-op classes and counts) but it's there, and I don't see any real source code anywhere. They also have patch registers, so you can't even say it's not updatable. The POWER9 manual mentions six Instruction Mask Registers per core, but these registers are documented nowhere (I just spent a good 30 minutes digging through the giant register documentation PDFs and HCODE source, but I couldn't find anything).

Is this better than Intel? Yes. Is it "fully free"? No. Nothing's fully free. Which is why we need nuanced analysis, not the nonsense arbitrary lines the FSF draws in the sand.