As /dev/mem gives you uncontrolled access to the entire memory, you need administrative rights to open the device. If you are concerned about security, it should possible to drop privileges after opening the device; However, the program has to be started as root, either from root account, or as suid root.
j. On Wed, Feb 4, 2015 at 6:27 AM, Julian Gold <[email protected]> wrote: > This - like several solutions - tries to open /dev/mem for read and write. > On my Rev C debian BBB, this operation fails, I suspect due to access rights > as it seems like it may need root access privilege? (Similarly for the sysfs > method, you can't write to sys/class/gpio/export unless you're root, making > it easy from a shell using sudo, and a PITA from C++). Is that correct? > > On Thursday, 11 July 2013 06:05:09 UTC+1, Jacek Radzikowski wrote: >> >> I wrapped the code up and posted the library on github. It is more of >> a framework, which allows to write applications that can be easily >> ported between different platforms. The GPIO access is just a small >> part of the library. >> Currently I have only implementation for Beaglebone, but RPI port >> should be trivial to make. I'm also thinking about a version for >> Cortex MCUs. >> Please check out, clone and comment at https://github.com/piranha32/IOoo >> >> j. >> >> >> On Tue, Jun 18, 2013 at 2:58 AM, Jacek Radzikowski >> <[email protected]> wrote: >> > I'm pretty close to having some code ready for release. All what is >> > left is to get rid of the most obvious bugs, clean up the code a bit, >> > add simple makefile and I think I will be ready to post it. My current >> > biggest headache is the crosscompiler. I've been using pre-compiled >> > g++ from Angstrom, but it adds some memory leaks to the compiled >> > programs. Running valgrind on a trivial cross-compiled "Hello world" >> > shows big allocation and memory corruption problems localized >> > somewhere around main(). The same code compiled natively on beaglebone >> > passes all the checks. I'm building right now new cross-toolchain with >> > angstrom and I hope it will work better and will fix most of the >> > memory-related problems I was observing. >> > I will definitely need testers, so I'll post information to the list >> > as soon as the library will be ready for download. >> > >> > j. >> > >> > >> > >> > On Tue, Jun 18, 2013 at 2:21 AM, MH <[email protected]> wrote: >> >> Jacek, >> >> >> >> so after some experimenting with the libraries and using sysfs to >> >> control >> >> the GPIO pins. I have found that this method of toggling gpio pins is >> >> extremely slow. It is great for simple applications, yet is really >> >> limiting. I think the best case on-off time toggling the pins is about >> >> .1 >> >> milliseconds on the BBB. How is your library progressing? Is there >> >> anything you are particularly stuck with? >> >> >> >> Thanks, >> >> >> >> Mark >> >> >> >> -- >> >> For more options, visit http://beagleboard.org/discuss >> >> --- >> >> You received this message because you are subscribed to the Google >> >> Groups >> >> "BeagleBoard" group. >> >> To unsubscribe from this group and stop receiving emails from it, send >> >> an >> >> email to [email protected]. >> >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> >> >> > >> > >> > >> > -- >> > Given a choice between two theories, take the one which is funnier >> >> >> >> -- >> Given a choice between two theories, take the one which is funnier > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- Given a choice between two theories, take the one which is funnier -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
