Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Hard, Not Soft, Kill Switches

puri.sm

Post reply on HN
Print view View original

11–20 of 82 posts

Re: Hard, Not Soft, Kill Switches

#11

Post by cnvogel »

slasaus wrote: post #10
cnvogel wrote: post #8

Ok, maybe I've been doing too much hardware development and more tinkering than the average guy, but this part here, to me, sounds way overblown: > As you can see, it is not a trivial matter to > manufacture these HKSes. A lot of research and > hard work went into the effort. I mean, compared to all the other things one has to get right to design a laptop computer, switching these few signals is indeed very, very tri…

It's even a bit worse when looking at it from a fail-safe point of view. To turn the bluetooth and wifi off , 3.3 Volt has to be put on the pins. Giving no power on the pins turns both devices on .

No, that's probably just by convention. If it's strictly an input then both directions are just the same in terms of safety. It's just sometimes more convenient to only pull things down or up and have a resistor provide the opposite pullup/pulldown current.

Maybe it was chosen because the "high" voltage isn't specified and the standard might say: "Pull down to GND to activate, leave open to keep card off." Then you don't have to think about the internal logic voltage of the circuit, you might fry the card if you pull up to 3v3 if the logic input is only 1.8V tolerant.

Re: Hard, Not Soft, Kill Switches

#12

Post by swalsh »

This is the first I've heard of Puri.sm. It seems like a very ambitious company. I'm not sure features like this are important enough to me to persuade my buying decision. However I love the idea of having another choice besides apple when it comes to hardware. I've just been really unhappy with everything else. I'm excited for another choice when looking for a high-end laptop!

Re: Hard, Not Soft, Kill Switches

#13

Post by mbrutsch »

slasaus wrote: post #10
cnvogel wrote: post #8

Ok, maybe I've been doing too much hardware development and more tinkering than the average guy, but this part here, to me, sounds way overblown: > As you can see, it is not a trivial matter to > manufacture these HKSes. A lot of research and > hard work went into the effort. I mean, compared to all the other things one has to get right to design a laptop computer, switching these few signals is indeed very, very tri…

It's even a bit worse when looking at it from a fail-safe point of view. To turn the bluetooth and wifi off , 3.3 Volt has to be put on the pins. Giving no power on the pins turns both devices on .

Devices that function when the power has been disconnected would be wonderful energy-saving devices.

Re: Hard, Not Soft, Kill Switches

#15

Post by throwaway7767 »

cnvogel wrote: post #8

Ok, maybe I've been doing too much hardware development and more tinkering than the average guy, but this part here, to me, sounds way overblown: > As you can see, it is not a trivial matter to > manufacture these HKSes. A lot of research and > hard work went into the effort. I mean, compared to all the other things one has to get right to design a laptop computer, switching these few signals is indeed very, very tri…

Agreed, they're way overstating the difficulty here. I think they just wanted to advertise that they do this, which is fair, and it's a feature I wish more laptops had.

Re: Hard, Not Soft, Kill Switches

#16

Post by mvdwoord »

I wonder if there would be any way to use some other component in a laptop as a microphone. Similar to the Funtenna stuff demoed by Ang Cui in several of his talks. https://www.blackhat.com/us-15/briefings.html#emanate-like-a...

I'm unsure on how that would perform practically with audible soundwaves or if any other research has been done in that area. It would however be hard to mitigate, if possible at all.

Re: Hard, Not Soft, Kill Switches

#17

Post by throwaway7767 »

toothbrush wrote: post #2

Great! Small point though, i would be in favour of a separate Bluetooth and Wifi kill switch. EDIT: They use i5 and i7 processors, which IIRC use black-box Intel microcode... Also, i wonder if they support Libreboot? My apologies if it turns out i cannot read. Otherwise they look quite nice. I'm excited to see more "alternatives" in the "free as in liberty" laptop space. EDIT 2: Some more information here: https://ww…

> EDIT: They use i5 and i7 processors, which IIRC use black-box Intel microcode... Also, i wonder if they support Libreboot? My apologies if it turns out i cannot read. Otherwise they look quite nice. I'm excited to see more "alternatives" in the "free as in liberty" laptop space.

They are going to use coreboot, which is free but includes some binary blobs from Intel. I don't think you can boot any modern x86 without a binary blob from the CPU manufacturer, unfortunately.

I also don't think it's possible to get any modern machine up without some device firmware blobs. The best-case is that all the blobs are provided onboard so the OS doesn't need to provide them, but they're still there and we have to trust them.

Purism seems to me an incremental improvement and I might buy one, but I really hope for a truly free machine someday.

Re: Hard, Not Soft, Kill Switches

#19

Post by witty_username »

throwaway7767 wrote: post #17
toothbrush wrote: post #2

Great! Small point though, i would be in favour of a separate Bluetooth and Wifi kill switch. EDIT: They use i5 and i7 processors, which IIRC use black-box Intel microcode... Also, i wonder if they support Libreboot? My apologies if it turns out i cannot read. Otherwise they look quite nice. I'm excited to see more "alternatives" in the "free as in liberty" laptop space. EDIT 2: Some more information here: https://ww…

> EDIT: They use i5 and i7 processors, which IIRC use black-box Intel microcode... Also, i wonder if they support Libreboot? My apologies if it turns out i cannot read. Otherwise they look quite nice. I'm excited to see more "alternatives" in the "free as in liberty" laptop space. They are going to use coreboot, which is free but includes some binary blobs from Intel. I don't think you can boot any modern x86 without…

AFAIK the microcode updates aren't mandatory, you can use your computer without them and use the stock microcode (though that's also proprietary).

Re: Hard, Not Soft, Kill Switches

#20

Post by throwaway7767 »

witty_username wrote: post #19
throwaway7767 wrote: post #17

Earlier quoted context omitted.

> EDIT: They use i5 and i7 processors, which IIRC use black-box Intel microcode... Also, i wonder if they support Libreboot? My apologies if it turns out i cannot read. Otherwise they look quite nice. I'm excited to see more "alternatives" in the "free as in liberty" laptop space. They are going to use coreboot, which is free but includes some binary blobs from Intel. I don't think you can boot any modern x86 without…

AFAIK the microcode updates aren't mandatory, you can use your computer without them and use the stock microcode (though that's also proprietary).

> AFAIK the microcode updates aren't mandatory, you can use your computer without them and use the stock microcode (though that's also proprietary).

Microcode is only one part of it. I was thinking of the ME firmware, and to a lesser extent the FSP. It's not possible to boot a modern Intel processor without ME. The ME has direct DMA access to all peripherals and can use the network interfaces directly, behind the operating systems back.

I believe AMD has similar things. They are all signed by the manufacturer and the hardware will refuse to load a replacement even if it existed.

Post reply on HN