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Comment Re:Try Stack Overflow and --synclines (Score 3) 91

Besides devKitARM, there is the collection of toolchains mentioned here. I am getting most of my clues from the Emcraft toolchain, which is the only one for the SmartFusion. And we're great friends with Emcraft, but I want something a bit newer and a different build-tree style.

My last approach to the libstdc++ mailing list, here, was left unanswered. I figured out the problem behind that one, but it would have been nice to get some advice.

Autoconf doesn't have a --synclines flag, but I might be able to pass it in the M4 environment variable. I'll give it a try.

Comment autotools is no fun (Score 5, Insightful) 91

I've been configuring a toolchain for Algoram's programmable radio transceiver, which has a SmartFusion 2 containing a Cortex M3. Until today, I've been working with GCC 5.1. Building GCC for cross-compilation on a no-MMU, no-FP processor and a software platform that doesn't support shared libraries isn't trivial, though it should be. GCC has many configure scripts, one for each library that it builds and at least one for the compiler. You run across many configure issues which are difficult to debug. For example, the configure file, a macro-expanded shell script, doesn't have source code line numbers from its configure.ac file. Error messages do not in general indicate the actual problem, and are difficult to trace. Figuring out what to fix is far from trivial. I ended up not being able to use multilibs (which would have allowed me to build for FP processors like Cortex M4F as well), couldn't link in ISL, couldn't build libjava.

Some of these are beginner problems - I'm new to building cross-toolchains and have avoided autotools as much as possible before this project. But not all of them.

One would think that we could build a better system today than such voluminous M4 and shell. Perhaps basing it on a test framework might be the right approach.

Comment Only good for "Near Space", not orbital re-entry (Score 1) 62

First of all, this is really old news. SpaceShip One no longer flies and has been a museum piece for years, and Virgin's burned their bridges with Scaled Composites and thus made it a lot less likely that they will be able to mount a near space effort with the SpaceShip Two design.

Second, this is not an orbital re-entry system, because it's not well-suited for a heat shield and thus can't do the necessary atmospheric braking. It's just a system to get you back from high altitude suborbital flights.

Comment Re:By comparision (Score 1) 274

You make a good emotional appeal, but the reality is that someone just casually sharing a song isn't likely to be subject to these penalties at all.

That's sort of like saying the penalty against burglary would only be used against someone who steals the Crown Jewels.

If the law specifies a minimum offense at all, you can be sure that anyone reaching that minimum is at risk. We've had very many documented civil copyright trolls going after otherwise un-notable individuals, and thus abuse of criminal law is certain.

Comment Re: Not even a link to the article (Score 1) 171

It would have to be many farads, this isn't a car stereo. The problem is how to gate the power after such a large capacitor. You're right that it could increase the momentary current. But that's also the problem. Their "contactor", a mechanical switch, has had to be upgraded with exotic alloy to deal with heating. And if you try to gate the power before it, you end up feeding what is very close to a short circuit while it charges.

Comment Fun, But Useless (Score 3, Funny) 148

This is a fun device that can show you what can be done with 3D printed plastic. That said, it's useless. It would be really cool if I could apply 1 pound of force to the crank, turn it a Million times, and have it apply a Million pounds of rotational force at the other end. But it's made of plastic, so it won't do that. Indeed, the fast-rotating parts would wear out before the slow-rotating part made a single turn. So it's not even good as a kind of clock.

All that said, it's a good conversation piece, and probably worth the price for that.

Comment iOS users feel it (Score 1, Insightful) 311

I currently have a web radio transceiver front panel application that works on Linux, Windows, MacOS, Android, Amazon Kindle Fire, under Chrome, Firefox, or Opera. No porting, no software installation. See blog.algoram.com for details of what I'm writing.

The one unsupported popular platform? iOS, because Safari doesn't have the function used to acquire the microphone in the web audio API (and perhaps doesn't have other parts of that API), and Apple insists on handicapping other browsers by forcing them to use Apple's rendering engine.

I don't have any answer other than "don't buy iOS until they fix it".

Comment Re:Randomness can't come from a computer program (Score 1) 64

Most of us do have a need to transmit messages privately. Do you not make any online purchases?

Yes, but those have to use public-key encryption. I am sure of my one-time-pad encryption because it's just exclusive-OR with the data, and I am sure that my diode noise is really random and there is no way for anyone else to predict or duplicate it. I can not extend the same degree of surety to public-key encryption. The software is complex, the math is hard to understand, and it all depends on the assumption that some algorithms are difficult to reverse - which might not be true.

Comment Re:Bad RNG will make your crypto predictable (Score 2) 64

The problem with FM static is that you could start receiving a station, and if you don't happen to realize you are now getting low-entropy data, that's a problem.

There are many well-characterized forms of electronic noise: thermal noise, shot noise, avalanche noise, flicker noise, all of these are easy to produce with parts that cost a few dollars.

Comment Randomness can't come from a computer program (Score 2, Interesting) 64

True randomness comes from quantum mechanical phenomena. Linux /dev/random is chaotic, yes, enough to seed a software "R"NG. But we can do better and devices to do so are cheap these days.

I wouldn't trust anything but diode noise for randomness. If I had a need to transmit messages privately, I'd only trust a one-time pad.

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