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Bug Software Linux

Linux Developers Consider On-Screen QR Codes For Kernel Panics 175

Posted by timothy
from the take-a-picture-it'll-last-longer dept.
An anonymous reader writes "Linux kernel developers are currently evaluating the possibility of using QR codes to display kernel oops/panic messages. Right now a lot of text is dumped to the screen when a kernel oops occurs, most of which isn't easily archivable by normal Linux end-users. With QR codes as Linux oops messages, a smart-phone could capture the display and either report the error string or redirect them to an error page on Kernel.org. The idea of using QR codes within the Linux kernel is still being discussed by upstream developers."
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Linux Developers Consider On-Screen QR Codes For Kernel Panics

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  • Re:Huh? (Score:5, Interesting)

    by ledow (319597) on Saturday April 05, 2014 @07:38PM (#46672973) Homepage

    You lose nothing.

    Anything that could have been logged to disk will have been.

    Anything that couldn't is probably FAR TOO LONG to even start taking down any other way and almost certainly will cut through the screen buffer limit anyway (every kernel panic I've had - which is about a dozen I think - was like that).

    Let's compare and contrast to, say, Windows. Bluescreen with minidump and error code that has 7 million potential causes.

    At least with a QR code, for those totally undumpable errors, you stand half a chance of snapping it and providing several kiloybytes of useful information for someone to work from - that they know hasn't been transcribed wrongly. And can be taken from even a completely hung machine.

    It's a good idea. Someone needs to make a patch for it. The biggest problem - as always - will be making sure you can get to the point that you can write to the video memory and do so with enough processing / storage to be able to write something useful into the QR code.

  • Re:Good idea (Score:2, Interesting)

    by Anonymous Coward on Saturday April 05, 2014 @11:09PM (#46673787)

    You just have to reprogram the VGA font table with 2 wide by 4 high bitmaps (because you can fit 256 such glyphs into the standard vga font table), and you now have 16000 pixels to work with instead of 2000, a bitmap display with a 160x100 pixel resolution; VGA text mode is 640x400 pixels, and each virtual pixel is 4x4 screen pixels, the standard VGA font is 8x16 pixels.

    BTW, you can't encode 2000 bits into a QR code with a 2000 bit bitmap, as it has parity and spatial clock recovery built in to the code.

    Since the system has crashed, there is no harm in replacing the vga font table, and it is so universal that you can do it on all hardware with VGA (the font table is always at a fixed memory address in PC architecture) without any interaction with device drivers.

    Of course you can also put the VGA into a standard graphics mode with no knowledge of the previous graphics card state, simply by programming known io ports with known values, this actually seems altogether more reliable than relying on the Linux framebuffer drivers which don't always work when X11 drivers are using the hardware, but could be considered reliable if KMS is used.

  • Just show smileys (Score:3, Interesting)

    by Anonymous Coward on Sunday April 06, 2014 @03:10AM (#46674415)

    Linux must be ubuntufied. We need to hide everything because it's way to complicated for the common user or his dog. We need more splash-screens to hide all the stuff that makes no sense anyway. Who want's to know if a module didn't get loaded? As a matter of fact, we should remove unnecessary logs (like message, dmesg, audit), because nobody gives a rats ass. Also: Why have a console? Or init-mode 3 ? People want the graphical stuff, let's get rid of all the ballast like command-line. Those few people still using ancient tools like 'make', 'vi' or (o my god) 'ifconfig' should go and find themselves something else to brag with. Linux MUST go mainstream.

What this country needs is a dime that will buy a good five-cent bagel.

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