linux
LEDs on cubietruck / armboards
It can be configured, it’s just not enabled by default (mostly).
Try entering ls /sys/class/leds/ to check what LEDs are available,
cat /sys/class/leds/
cat /sys/class/leds/white:ph11:led3/trigger
[none] battery-charging-or-full battery-charging battery-full battery-charging-blink-full-solid ac-online usb-online mmc0 mmc1 timer disk-activity heartbeat backlight cpu0 cpu1 default-on rfkill0 rfkill1
and setting them manually, example:
echo “mmc0″ > /sys/class/leds/blue:ph21:led1/trigger
echo “heartbeat” > /sys/class/leds/green:ph07:led4/trigger
echo “cpu0″ > /sys/class/leds/orange:ph20:led2/trigger
echo “cpu1″ > /sys/class/leds/white:ph11:led3/trigger
You need to use root shell to test setting triggers, using sudo from non-privileged user won’t work.
To enable them at every boot, you can edit .fex file (and recompile it to bin afterwards) on old kernel, .dts file with dtc (it’s a little bit tricky) on mainline, or just put echo commands to /etc/rc.local.
ctags
ctags -R *
Ctrl+] – go to definition
Ctrl+T – Jump back from the definition.
Ctrl+W Ctrl+] – Open the definition in a horizontal split
Add these lines in vimrc
map <C-> :tab split
map <A-]> :vsp
Ctrl+\ – Open the definition in a new tab
Alt+] – Open the definition in a vertical split
Attach to process
create a pipe: mkfifo /tmp/fifo.
Use gdb to attach to the process: gdb -p PID
Then close stdin: call close (0); and open it again: call open (“/tmp/fifo”, 0600)
Finally, write away (from a different terminal, as gdb will probably hang):
echo blah > /tmp/fifo
========
view only:
cd /proc/PID/fd
tail -f 1..3