dpkg -l | grep gcc | awk '{print $2}'

First erased the current update-alternatives setup for gcc and g++: (not Neccesery)

# sudo update-alternatives --remove-all gcc
# sudo update-alternatives --remove-all g++

Install Packages

It seems that both gcc-4.3 and gcc-4.4 are installed after install build-essential. However, we can explicitly install the following packages:

sudo apt-get install gcc-6 g++-6

Install Alternatives

Symbolic links cc and c++ are installed by default. We will install symbol links for gcc and g++, then link cc and c++ to gcc and g++ respectively.

#sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 10
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-6 20

#sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 10
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-6 20

sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc 30
 sudo update-alternatives --set cc /usr/bin/gcc

sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++ 30
 sudo update-alternatives --set c++ /usr/bin/g++

Configure Alternatives

The last step is configuring the default commands for gcc, g++. It’s easy to switch between 4.3 and 4.4 interactively:

sudo update-alternatives --config gcc
 sudo update-alternatives --config g++


gcc -v
g++ -v

http://askubuntu.com/questions/26498/choose-gcc-and-g-version


Compile tinyos3

Download tinyos3.zip
unzip tinyos3.zip
sudo apt-get install valgrind

nano kernel_sched.c

--- Line 59 ---

//#define MMAPPED_THREAD_MEM

replace

#define MMAPPED_THREAD_MEM

touch .depend
 make

./validate_api basic_tests