POSIX Compliance (Getting started challenge for RTEMS beginners)

POSIX stands for Portable Operating System Interface for uni-X. POSIX Compliance allows us to port the source code that is running on one machine, can be run on another machine.

This Project deals with the implementation of a subset of functions that are defined in POSIX 1003_1 standard, Due to physical resource constraints, some real-time systems like the small embedded system needs a limited set of operating system functionality. For these type of system, it is necessary that the standards allow the implementation to support only a particular subset of POSIX functions. Real-Time Working Group addressed this subset of function.POSIX profiles defined in FACE Technical Standards, designed for avionics system versus POSIX in RTEMS where some functions are missing.

RTEMS Initial Setup:

Step 1: Install prerequisites

$ sudo apt-get install build-essential
$ sudo apt-get build-dep binutils gcc g++ gdb unzip git python2.7-dev
$ sudo apt-get install git

Step 2: RTEMS prefix and setting path

$ export PATH=$HOME/development/rtems/5/bin:$PATH

Step 3: RTEMS setup

$ mkdir development/rtems/src
$ cd development/rtems/src

2019-06-15-Fourth-Post Step 4: Clone RTEMS Source Builder git repository (within the src directory):-

$ git clone git://git.rtems.org/rtems-source-builder.git
$ cd rtems-source-builder

Step 5: Now we check whether the host is setup correctly or not using this command:-

$ source-builder/sb-check

If this message appeared in the terminal that means the host is set up correctly.

“RTEMS Source Builder environment is ok.”

Step 6: To check the list of architectures, supported by RTEMS

$ ./source-builder/sb-set-builder list-bsets

Step 7: For SPARC architecture :

$ cd rtems
$ ../source-builder/sb-set-builder --log=l-sparc.txt --prefix=$HOME/development/rtems/5 5/rtems-sparc

Note : If Building process is failed, then go to the directory /develeopment/rtems/src/rtems-source-builder/rtems and check the reason in log file sparc.txt file.

This command download, build and install the tool chain here :


Step 7: Now environment for SPARC is set up. We need to download rtems5.

$ cd
$ cd development/
$ git clone git://git.rtems.org/rtems rtems5
$ ls $HOME/development/rtems/5/bin

Step 8: Configuring and compiling RTEMS5:-

$ cd rtems5
$ export PATH=$HOME/development/rtems/5/bin:$PATH
$ ./bootstrap
$ cd ..
$ sudo rm -r b-sparc
$ mkdir b-sparc
$ cd b-sparc
$ ../rtems5/configure --target=sparc-rtems5 enable-rtemsbsp=erc32 --enable-tests=samples \ 
$ make
$ sudo PATH=$HOME/development/rtems/5/bin:$PATH make install

Step 9: To check whether the hello world.exe is generated or not, try this command :-

$ cd development/b-sparc

$ sparc-rtems5-gdb `find . -name ticker.exe`

Here, we can use path of .exe file within the testsuites instead of find command. I had modified the ticker application.

To modify any tests, one needs to go to the samples directory located at $HOME/ development/rtems5/testsuites/samples/

Go to any specific application directory and change the code.

After adding code or modifying any file, you need to run make and make install(use sudo with PATH) commands.

Above command find the hello.exe file.

$ tar sim

$ load

$ r

Done :) Send the output and patch on devel@rtems.org

Written on May 25, 2019