use get_random_int() to fix entropy depleting
patch from https://patchwork.kernel.org/patch/1745611/

Change-Id: Ifdbe05fab5849c151fdb95fc85a56045a03dd5c7
Fix build with linaro

Change-Id: I213ed58b0fbb00e4b27aba850e488127b6383165
Various performance tweaks

Change-Id: Ic6ef4a08f2ce637b4b251449e12637775597fa76
Fix wifi interruptions

Change-Id: I9d108bdd841625ae045a47a0921203b70f365fc4

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>