Kernel coding standard

Kernel coding standard published on kernel.org differs from others by style which is used there. It made me smiled during reading, following lines are copied from it :

"However, if you have a complex function, and you suspect that a
less-than-gifted first-year high-school student might not even
understand what the function is all about"

Overall, there are many "weak" points highlighted there which should be considered.

Coding style [kernel.org]

Reciprocal multiplication

I have posted here links which were dedicated to the multiplication and division. I had to get back to it today because was not sure what does constant mean in one assembly code (0x199A).

Reciprocal Multiplication [homepage.cs.uiowa.edu/~jones]
Here was the answer to that constant, why to use fixed point arithmetic on dividing, also explanation why 0xCCCD is used to calculate 1/10 of a value.

I am glad it brought up the topic back and I had to revise it.

Sublime Text 2 for C/C++ development

I've decided to use VIM for my development. Although I installed it long time ago, I have not gave it a shot. On the other hand, I started using Sublime. The beginning was like notepad++ feeling, what does sublime offer more, I marveled. That's been itching my conscience and therefore I watched few tutorials and opened Sublime Text Cheat Sheet. Since that moment, I've pleasantly been using it with much more effectivity. Here I present most used shortcuts which makes my development faster ( take it as is, because I am still learning).

This document covers a lot, but I recommend to watch tutorials
Tutplus.com Sublime [tutsplus.com]

After you complete it, check this and write down (memorize) which you consider important.
Sublime Text Cheat [pastebin.com]

Plugins make sublime powerful, I use so far these - Linter (with cppcheck), CodeIntel, Bracket Highlighter.

The only problem I had, was to set up cppcheck in Linter, paste this into user settings for Linter (path to cppcheck)

{

"sublimelinter": "load-save",

"sublimelinter_executable_map": {

"c" : "C:/Program Files/Cppcheck/cppcheck.exe",

"c++" : "C:/Program Files/Cppcheck/cppcheck.exe"

},

"sublimelinter_gutter_marks": true,

"sublimelinter_popup_errors_on_save": true,

"sublimelinter": "save-only"

}

Happy coding and don't use a mouse, use a keyboard with shortcuts!

ARM compiler (armcc) and ARM archiver (armar)

I usually create libraries with an extension .a or .lib. As I glanced at mbed, their own library has extension .ar. KEIL comes with ARM Compilation Tools [www.keil.com]), which is used also for embed library, as I believe.

To compile files from which we want to create a library (target is Cortex-M0+).

armcc --cpu=Cortex-M0plus --no_debug -c file1 file2 fileXY

To create static library from object files

armar --rv archive_name object_file1 object_file2 object_fileXY

I successfully imported small static library to mbed and run it on my mbed board. There are many options to select. To read more here are the links:

Creating static software libraries with armar (pdf) [infocenter.arm.com/help]
Getting Started with the Compiler [keil.com]

Optimalization + aliasing in C programs (bookmark)

An article about pointer aliasing, using local variables over global and few more tips.

Optimizing C programs [eetimes.com]

GNUplot

There was a demand to process all testing data and generate graphs. There was a perl script to process everything but was outdated. To plot the graphs it used GNUplot. I found lack of documentation, although everything I found on the internet (blogs, stackoverflow). What my parser required was to use multiplot to generate 3 rows and 2 colums graphs, read data from files.  The each column has to have own title above them.

GNUplot is really powerful and I will be happy to use it once again.