Understanding the Linux Kernel via Ftrace

Ftrace is an internal tracer designed to help out developers and designers of systems to find what is going on inside the kernel. It can be used for debugging or analyzing latencies and performance issues that take place outside of user-space. Although ftrace is typically considered the function tracer, it is really a frame work of several assorted tracing utilities. There's latency tracing to examine what occurs between interrupts disabled and enabled, as well as for preemption and from a time a task is woken to the task is actually scheduled in. One of the most common uses of ftrace is the event tracing. Through out the kernel is hundreds of static event points that can be enabled via the tracefs file system to see what is going on in certain parts of the kernel.

Installing Kali NetHunter on Nexus 7 Tablet

Making notes here regarding Kali NetHunter installed on a Nexus 7 tablet.  I noticed this was possible when looking on ebay for a Nexus 7 for a car computer installation.

Research Links

 

YouTube: How To Install Kali On Nexus 7 [2016] High Quality

Icarus CarPi CarBerry – CarPuter Informatic Devices to Replace your car radio

This effort has been superceded again as was the last because it appears the Chinese have made several variants of their own leaving this particular design orphaned by the originators.  I can not get a response from them regarding if the project is still active.  I have also seen a person in their forum that needs help getting his software installed complaining he can not reach anyone.

This effort has been superceded by:  Android Based Car Computers Carputers

There are several Raspberry Pi based computer design for cars.  

Research Links

Lintz’s Notes about Android Rooting and Unlocking

General point, all phones:  As I unlocked various phones over the years, i found xda-developers forums to be the best for knowledge and tools: 
I did not use them immediately time,which cost me some time. should have used the geeky way below
 
(samsung galaxy s vibrant (sgh-t959) xda-dev geeky way)

Quick Explanation:
xda page with unlock tools:
 
Samsung Galaxy S Vibrant sgh-t959 no brain, tools way, which i used. I now remember what messed me up was getting the kies usb drivers to work (i am on win7). threw away notes but my memory is:
– Was amazed it actually worked!
 
Good luck, xda-dev is your friend …

Adding Display Resolutions to Ubuntu Linux

I connected my Ubuntu laptop to an external 24 inch monitor.  I then tried to set the resolution to a level appropriate for a 24 inch monitor: 1920×1200.  However when I looked in the settings the highest resolution was quite low.  I had to add additional resolution levels manually. 

Research Links

I followed the procedures detailed in the linked articles.  When I tried 1920×1200 resolution with 60Hz frequency it did not show up in the configuration gui list.  It must have been illegal.  When I changed to 70Hz it did work.   Note that it is important to generate the mode line individually for each resolution/frequency combination.  I did a bonehead thing and reused the line for the 1280×1024 for the 1920×1200 mode and of course that did not work. 

The changes made are not permanent and upon reboot will be lost.