1.3. Extracting the Root Filesystem

After installing the toolchain, for some use cases you might need to separately extract a root filesystem:

To extract the root filesystem, first source the cross-development environment setup script to establish necessary environment variables. If you built the toolchain in the Build Directory, you will find the toolchain environment script in the tmp directory. If you installed the toolchain by hand, the environment setup script is located in /opt/poky/2.3.

After sourcing the environment script, use the runqemu-extract-sdk command and provide the filesystem image.

Following is an example. The second command sets up the environment. In this case, the setup script is located in the /opt/poky/2.3 directory. The third command extracts the root filesystem from a previously built filesystem that is located in the ~/Downloads directory. Furthermore, this command extracts the root filesystem into the qemux86-sato directory:

     $ cd ~
     $ source /opt/poky/2.3/environment-setup-i586-poky-linux
     $ runqemu-extract-sdk \
        ~/Downloads/core-image-sato-sdk-qemux86-2011091411831.rootfs.tar.bz2 \
        $HOME/qemux86-sato
        

You could now point to the target sysroot at qemux86-sato.