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Comment: Re:Fedora can be annoying.. (Score 1) 116

by petermgreen (#47409781) Attached to: CentOS Linux Version 7 Released On x86_64

Do network drivers, serial drivers, input drivers, storage drivers, filesystem drivers and so-on belong in the kernel? microkernel advocates would say no, most designers of operating systems that actually get used have said yes.

I don't see how at least the low level part of a video driver is any different.

Comment: Re:Failsafe? (Score 1) 462

I'm sure people said the same about fly by wire when it was first suggested.

Yes it will likely take many years of experimentation, risk calculation, arguments with regulators and so-on to turn this from a concept into an actual product but I don't see any reason why it couldn't be delivered at an acceptable risk level.

Comment: Re: Failsafe? (Score 1) 462

Yes there is some risk of a total hydraulic or electrical failure but nevertheless the benefits from having larger planes than are practical with manual flight controls were deemed to outweigh those risks. Similarly the benefits from having a stronger more aerodynamic airframe and better visibility under normal conditions may be deemed to outweigh the risks of total camera system failure combined with a situation that prevents landing on instruments or a hazard that can only be spotted visually.

You will never reduce the risk of flying to zero, there always has to be some balance.

Comment: Re:Is it really a single board computer? (Score 1) 122

by petermgreen (#47397363) Attached to: New Single Board Computer Lets You Swap Out the CPU and Memory

The documentation for using the module on your own board is available from the B2B section of their site. The connectors are off the shelf parts from hirose.

However while desinging and making a carrier for this will be much easier than designing with the imx6 directly it's going to be beyond most hobbyists. The connectors have a pin spacing of 0.4mm and massive numbers of pins.

Comment: Re:So the Chinese have created a free market econo (Score 1) 131

by petermgreen (#47397289) Attached to: Oculus Suspends Oculus Rift Dev Kit Sales In China

laws in most countries would probably support the consumer if they tried to return an unopened product in a reasonable time window.

At least here in the UK there is a lot of protection for consumers but far less protection for people buying stuff for buisness reasons. The tricky bit of course is distinguishing real consumers from failed scalpers fraudulantly claiming to be consumers.

no idea if the same applies in other countries.

Comment: Re:Banana Pi, Cubieboard, ODroid, BeagleBone ... (Score 1) 122

by petermgreen (#47393667) Attached to: New Single Board Computer Lets You Swap Out the CPU and Memory

It's difficult to tell for sure without benchmarking individual applications. Having said that some general points

The odriod line like the Pi have USB based ethernet (though some odriod models have multiple USB busses from the SoC unlike the Pi) and no SATA ports, I'd avoid them for anything storage/network heavy. IIRC they are also lagging behind in terms of getting kernel support upstream. On the other hand when it comes to CPU power they are at the uppper end of what affordable arm boards offer.

The IMX6 based stuff (wandboard, cubox etc) seems like a pretty good all round choice, make sure you get a model with SATA if storage is important to you.

Most of the boards have some sort of GPIO but sometimes it's on awkward connectors or the software is immature. For some applications a board with a dedicated IO processor like the UDOO (or the arduino Tre when it's released) may be worth considering.

Comment: Re:Not impressed (Score 1) 122

by petermgreen (#47393565) Attached to: New Single Board Computer Lets You Swap Out the CPU and Memory

There is no such thing as a "generic arm board", there are a load of SoCs out there which while they share the CPU core design they are very different in pretty much every other way. The differences don't end at SoC level, there are many differences at the board level too. Most pins on a modern SoC are programable to multiple functions and if you want things to work then the important ones need to be programmed to match the hardware you have on the board. Enumeratable "plug and play" busses are they exception not the rule.

If you have documentation than porting the bootloader and kernel is likely to be hard work but doable, without documentation it is going to be extremely difficult. In my experiance kernels intended for andriod often have problems running regular linux userlands and vendor kernels are often way out of date. Also a serial console is needed to debug/troubleshoot this stuff and most phones/tablets don't have an easilly accessible serial console.

Once you have a usable bootloader and kernel then getting a generic linux system up and running is fairly easy. Of course if you want to use specific features of the chip (e.g. acceslerated graphics) then you will have more work to do.

Comment: Re:Sanitize crazyness (Score 1) 215

by petermgreen (#47337327) Attached to: Exploiting Wildcards On Linux/Unix

Take the C argument. The issue is really again one of input validation, buffer over flows happen ultimately because of of problems with input validation.

Sometimes they do, sometimes they happen because a series of inputs while valid individually nevertheless result when combined in a value too big for an internal buffer.

There have been plenty of exploits and injects in software written in Java, perl, Python, Ruby, BASIC, etc. It almost always comes down to input validation, and that is because input validation is *HARD* for any non trivial range of allowed inputs.

So you have three options
1: write a validator and assume the validator produces "safe" output
2: don't validate the data and treat it as potentially hostile whereever it passes in your system
3: write a validator but neverthless treat the data as potentially hostile even after passing through the validator. That way you have to screw TWO things up to get a serious exploit.

Then start mixing other technologies and it gets even more fun. So your C program is on a system using UTF-8, how big a buffer do you need to handle data from the database server with a VARCHAR(128) field? What character encoding is it using? What else writes data to that field what character encoding do those things use?

So you have three options
1: try to work out what the maximum size is and use a fixed buffer of that size with no bounds checking
2: do the above but put in checking so that if you screw things up you get an error instead of memory corruption.
3: use a buffer allocated on demand of the size that is actually needed.

Comment: Re:First post (Score 2) 274

by petermgreen (#47308781) Attached to: China Starts Outsourcing From<nobr> <wbr></nobr>... the US

Sometimes what they do is set up in the US but in a different part of the US. This allows them to sidestep protectionist import restrictions while also drawing from a different labour pool and avoiding existing unions.

Toyota has a number of factories in the US but none in detroit or even in mitchagan.

Comment: Re:Good luck with that (Score 1) 340

by petermgreen (#47288049) Attached to: Russia Wants To Replace US Computer Chips With Local Processors

Sure using a local design would be the ideal but that would require having a usable local design.

However local production has distinct advantages even if the design is imported. Firstly it makes it harder for other countries to cut off supply. Secondly it means that if a backdoor is to be slipped in it must be slipped in at a much earlier stage of the process making it harder to keep secret. Thirdly it means you are sending less money abroad.

"But this one goes to eleven." -- Nigel Tufnel

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