cnvogel

47 ms·

391.
by cnvogel 12y ago
Probably something along the lines of... (...) writing legacysystem_firmware.hex (387123 bytes) Build finished successfully, with 71245 warnings. Good look, finding the "unsigned short x = floatval;" line, that d
392.
by cnvogel 12y ago
Attempt at an explanation: To get a C-program to run, even an empty "int main(){ return 0;}" needs some supplemental code to set things up the way your main() function expects. This supplemental code is what the github repository
393.
by cnvogel 12y ago
Just a remark: If you find it confusing to scatter your code over too many small files with only one function each, look up "-ffunction-sections" on the gcc manual.
394.
by cnvogel 12y ago
... with nss-modules being a major culprit, ironically... (on which gethostbyname relies greatly)...
395.
by cnvogel 12y ago
In Europe (also including UK ;-) ), the joint Europe electrical grid is maintained according to the mechanism outlined in this technical document. https://www.entsoe.eu/fileadmin/user_upload/_library/publica..
396.
by cnvogel 12y ago
There must be a reference temperature sensor near the "cold junction", where the NiCr-Ni thermocouple wires are terminated. Remark: The external temperature probe is always called "hot", the reference junction always &qu
397.
by cnvogel 12y ago
According to the API, clock_gettime() can only error out for two reasons: EFAULT when the 2nd argument points to invalid memory or EINVAL when the clock is not supported on the system. The first thing is ensured in the code, the 2nd thing c
398.
by cnvogel 12y ago
Obviously, when comparing different methods of computation with negligible cache/memory footprint, I'd run it on hot caches to maximize the visible effect on the implementation. File here was about 1.5 GB on a 4GB RAM machine, and
399.
by cnvogel 12y ago
It's a nice trick, but it's not too "blazingly" fast. In [73]: cProfile.run('for i,v in enumerate(open(fn)): pass\nprint(i)') 15496799 406215 function calls in 10.998 seconds If you really
400.
by cnvogel 12y ago
Probably this stems from the typical C-way of error-reporting out of a for-loop, which is to terminate earlier than the "regular loop condition", and hence a second test for the loop-condition can easily be used to check for abnor
401.
by cnvogel 12y ago
I had to deinfect a adware infested computer of a colleague recently. In my oppinion, most adware is very eager to include some proper way of uninstalling, just to not be classified as a trojan/virus/... Even if this is complete
402.
by cnvogel 12y ago
Some people might remember from really old DOS games, but... You can even use the PC speaker as a "soundcard" (Actually as a 1-bit DAC. Here's the function called a few thousand times per second when using the Linux audio su
403.
by cnvogel 12y ago
You should point out that typical jitter on the digital interface will be in the order of few 100 PICOSECONDS...
404.
by cnvogel 12y ago
But here's the thing: The clock source that goes into your DAC isn't influenced by the pattern of packets arriving from your storage system, it's typically a standalone oscillator sitting in the vincinity of the DAC and its c
405.
by cnvogel 12y ago
An extreme example for this kind of approach might be found in the history of the Enigma cipher and the British/Allied successful attempts in decryping German communications during the war. If it would have been obvious that informatio
406.
by cnvogel 12y ago
Unfortunately the ssh-key (probably not the verbatim file, but of course the parts comprising the mathematical key) will have to stay in the sshd process' memory. If one wants to make it impossible for a "offline thief" (e.g.
407.
by cnvogel 12y ago
Even better, GPS itself is sending out the exact UTC offset (and start of validity/moment of insertion of leap seconds)... http://www.losangeles.af.mil/shared/media/document/AFD-10081... §20.3.3.5.2.4
408.
by cnvogel 12y ago
Workload is pretty low in either case... Here's the function in the Linux-Kernel that's counting the seconds. It's actually not specified if this function is called exactly every second, or more often, or less often. It just
409.
by cnvogel 12y ago
Appearing to do something against cyber terrorism, as some list of usernames, passwords and credit card numbers have shown up there in the past.
410.
by cnvogel 12y ago
Lawyers... the photographed piece of paper mentions, that the following URLs ought to be blocked, then lists URLs specifying a particular protocol and listing only the empty/top-level resource e.g. https://www.example.com&#
411.
by cnvogel 12y ago
So, what's the deal with just clicking away the warning, then? Still provides secrecy against a passive listener, better than plain http...
412.
by cnvogel 12y ago
Most PC sound cards employ so-called single-supply designs running their chips only between Ground and a single positive supply, e.g. 5V or 3.3V. So typically for a headphone output the amplifier will swing around 1.5 or 2.5V or so. To get
413.
by cnvogel 12y ago
Oh, yes. My pain exactly. I think word is, given the huge functionality made very accessible to pretty much anyone who can point at things with the mouse, quite impressive software. But let a few people edit a Word document in turn, on diff
414.
by cnvogel 12y ago
The ATMega128... parts are the second-to-largest 8-bit micro that Atmel sells, I think they already have a strange combination of a lot of flash & RAM (for a 8-bit CPU), but not that many, or that complex, peripherals. So they might onl
415.
by cnvogel 12y ago
> But what do you think that we can get out of this? One can learn that sometimes it's worthwhile, or even the prudent thing to do, to emulate the hardware instead of porting code. Emulating a 32bit CPU on a 8bit µC is certainly a l
416.
by cnvogel 12y ago
Contiki already runs natively on AVR. https://github.com/contiki-os/contiki/wiki/Avr-platforms
417.
by cnvogel 12y ago
Indeed, fascinating! The CPU will have to wait thousands of waitstates for each bytes from the SPI-flash, but who cares in the first few ms of booting ;-). Thanks for pointing me in that direction! There's quite some information also i
418.
by cnvogel 12y ago
> the first instruction after a reset is fetched from FFFF:FFF0 I trust you that this logically will certainly be true, but: what memory will that access to ffff:fff0 be mapped to if the "bios" in my PC is stored in a SPI flash
419.
by cnvogel 12y ago
Out of curiosity: Can anyone point me where to find how a recent x86-cpu actually boots? Where's the code that gets executed in the first few CPU cycles? The bulk of the firmware, that's clear, nowadays will be fetched from a seri
420.
by cnvogel 12y ago
Hey arbesfeld, I really like that project, and the nice writeup really presents it well. But especially as people might use it for inspiration for their own temperature-controlled cooking projects, I think the lack of a proper isolation of

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