On 6/29/14, Matthieu Herrb <matthieu.he...@laas.fr> wrote: > On Sun, Jun 29, 2014 at 12:31:16AM -0700, patrick keshishian wrote: >> On 6/29/14, Benjamin Baier <program...@netzbasis.de> wrote: >> > You can set the default securelevel in /etc/rc.securelevel. >> > The "logic behind that" is described in securelevel(7). >> >> locking down pins when/if another device driver is attached >> to them makes sense, but locking down idle pins ... i'm not >> too sure. especially since using them requires permission to >> the gpio device file in the first place. > > The difficulty is that from board to board supported by the same > kernel this wiring of the existing GPIO can vary. So you can't rely on > the kernel to know which pins are safe and wich are not. > > There are board design with really dangerous pins that are not > explicitely used by a given driver. Iirc on the armish Thecus N2000 > you can shut down the fans (and thus damage the disks insinde by > overheating) or cause an hard reboot.
Got it. Thanks. --patrick > So better safe than sorry, you really need to know what you're doing. > > Nothing prevents you to run permanently at securelevel 0 if you > need it and can afford the risk. > >> >> --patrick >> >> >> > On 06/29/14 06:18, patrick keshishian wrote: >> >> On 6/27/14, Raphael Graf <r...@undefined.ch> wrote: >> >>> On 06/27/14 06:58, patrick keshishian wrote: >> >>> >> >>> The direction of the pin has to be configured at securelevel 0. >> >>> You can put something like the following line in /etc/rc.securelevel: >> >>> gpioctl gpio1 23 set out >> >>> >> >>> Then you should be able to toggle the pin: >> >>> # gpioctl gpio1 23 on >> >>> pin 23: state 0 -> 1 >> >>> # gpioctl gpio1 23 off >> >>> pin 23: state 1 -> 0 >> >> >> >> Thanks for the hint! >> >> >> >> Though, this seems a rather painful way to play with those >> >> pins. Every time one wants to change a pin's direction or >> >> make use of a new pin, one has to reboot. >> >> >> >> Oh well... must be some logic behind that. >> >> >> >> --patrick >> > > -- > Matthieu Herrb
