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Embedded Linux 1-Second Cold Boot To QT
An anonymous reader writes "The blog post shows an embedded device cold booting Linux to a QT application all in just one second. This post also includes a link which describes what modifications were made to achieve this."
If the first thing that enters your mind when reading "QT" is QuickTime, you're on the wrong website I'm afraid.
If he came here for abuse, it's definitely the right website!
If the first thing that enters your mind when reading "QT" is QuickTime, you're on the wrong website I'm afraid.
It's usually rendered as Q t not Q T .
The have a slideshow here: http://www.slideshare.net/andrewmurraympc/elce-the , it's interesting starting at slide 19. Especially the executable reordering to defer loading of UI event handling code is impressive.
NB: The message above might reflect my opinion right now, but not necessarily tomorrow or next year.
...booted in about 5 seconds, and that was to a general desktop.
And my toy homebrew OS boots to a primitive UI in under 2 seconds after BIOS, and much of that is running interpreted bytecode.
The fact is that a full BIOS + Linux / Windows system is a horrible fucking mess of bloat, but part of it is the price you pay finding and initialising all those millions of third party devices your old/embedded device isn't going to need to worry about.
Still, as always, I believe any engineer's claim not before I get to test it myself.
I had the same reaction. The answer lies in the wikipedia, not in the unhelpful intermediate posts:
http://en.wikipedia.org/wiki/Qt_(framework)
Qt "is a cross-platform application framework that is widely used for developing application software with graphical user interface (GUI) (in which case Qt is referred to as a widget toolkit when used as such), and also used for developing non-GUI programs such as command-line tools and consoles for servers"
This is the NSA, we're gonna geet U h@x0r5! Also, what is a h@x0r5?
Its good to see a fun tech article like this on /. I haven't seen any in a while (maybe its just me).
I assume that during boot time, the Qt UI and low level hardware modules are loaded immediately. Then other modules and services can be loaded later on such as networking, video capture drivers and other lower priority services. I also assume the UI is not based on X but a Qt implementation that is directly drawing to the frame buffer.
Lately I have been on a bit of an embedded systems kick playing around with PLC's and embedded micro controllers. This is a great article.
I have to say, the most impressive/innovative tweak, to me, was the re-ordering of required functions in the compiled binary. Doing so allowed them to reduce load time, by making it that only two blocks had to be demand-read off the flash filesystem, instead of four.
That's some crazy, use-the-drum-spin-as-timing, innovative thinking right there. Serious kudos.
That's actually common practice in profile guided optimization, put commonly used code close together in the image to minimize the number of pages loaded.
This is the year of Linux on the de- wow, that was quick.
"We live in a global world" - Harvey Pitt, former Securities and Exchange Commission Chairman
as a corallary to OP: If the first thing that enters your mind when reading "QT" is QuickTime, you have a problem.
if you go to wikipedia for help? Now you have 2 problems.
can we please get back to arguing now?
Another optimization that was common old Mac compilers was "dead-stripping", where they avoided linking in any functions that were never called. Apparently this isn't commonly done and instead if a single function in a file is called, then ALL are linked in, at least when I looked into it for Linux a while back.
can we please get back to arguing now?
Yeah, right after I finish beating Doom III by "I.D." software running on my "MAC".
I wouldn't be surprised if the poster pronounces daemon as "daymon" either. The geek ego sure seems to get in the way of learning how to pronounce things. It looks like devs these days will have to provide audio files to show how to pronounce their work.
*shakes his head at correct pronunciation deniers*
Um. This capability has been around since FOREVER. I worked at MS 'beside' the group that created exactly such a tool, called BBT. This was ~2000.
It was the most used, but not the only result of a tool suite called Vulcan. This would allow you to pull apart and re-assemble a binary, either for re-ordering (optimization) or to add instrumentation for other optimization projects (like the one I worked on).
I know I'm going to get modded "off-topic", but this is getting too silly.
Spork.
P.S. Spork.
The Story of Mel! http://foldoc.org/The+Story+of+Mel (That's not the original, that's the "free verse" version which is better IMHO.) It might even be a true story! http://en.wikipedia.org/wiki/Mel_Kaye
You forgot to mention the performance died when marketing made you link in ie.h .
Got Code?
I came here to meet lonely singles in my area.
You are welcome on my lawn.
Um. This capability has been around since FOREVER. I worked at MS 'beside' the group that created exactly such a tool, called BBT. This was ~2000.
It was the most used, but not the only result of a tool suite called Vulcan. This would allow you to pull apart and re-assemble a binary, either for re-ordering (optimization) or to add instrumentation for other optimization projects (like the one I worked on).
You deliberately seem to miss one really important point.
These guys do not have to pull apart binaries they can mod them from source if they feel like it. You have let the cat out of the bag and admitted that Microsoft uses disassemble technique on other peoples binaries all the time. No wonder it was so easy for you guys to clone closed functions in IBM's Lotus Suite and com SQL framework, then pretend that you did not know what was going on when all of a sudden their binaries were slower and less reliable than yours!
So you guys have been doing what you say others have no business do to your software FOREVER. Face it... considering the fact that embedded Linux runs most TVs, BD players and other really popular devices on the market today, you are just mouthing a party line and not making a real valid argument why MS is losing out in the embedded products market!
There is also a PDF of the slides on the elinux.org web site under the 'Boot Time' page.
My thoughts exactly, I don't want to use non-free adobe flash and slideshare does not work with gnash. Fortunately a very similar looking PDF does seem to be available at
http://elinux.org/images/f/f7/RightApproachMinimalBootTimes.pdf