Using RTLinux
From Robots in everyday human environments
The CF card shipped with the Robotino® robot, contains a stripped Linux distribution, in the sense that the kernel source files and config have been removed. These are essential files, in order to be able to compile RTLinux modules for insertion in the kernel. Furthermore, since only about 8Mb of memory is available for the root user, if the original card is a 256Mb one, a larger card must be used in order to develop modules for the RTLinux environment. Assuming that a larger card is used, the packages listed in the Table below must be download and installed, using the same procedure as in Section Gaining root access to the operating system. Furthermore, the Kernel source files must be downloaded. On the Robotino® used in this project, the kernel installed from FESTO is the 2.4.29, which can be downloaded directly from http://www.kernel.org/pub/linux/kernel/v2.4/linux-2.4.29.tar.bz2. If other kernel sources are needed browse the kernel.org site.
RTLinux can be downloaded from rtlinuxfree.com (requires login),
the file is named rtlinux-3.2-rc1.tgz. Having downloaded the mentioned files, extract
them using the following commands from the terminal:
tar xzf /var/tmp/linux-2.4.29.tar.bz2 XXX tar xzf /var/tmp/rtlinux-3.1.tar.gz XXX
Now, copy the contents of the Linux source folder to the Robotino® by issuing:
scp -rf /var/tmp/linux/linux-2.4.29.tar.bz2 root@172.26.1.1:/usr/src/linux
and the RTLinux files as follows:
scp -rf /var/tmp/linux/linux-2.4.29.tar.bz2 root@172.26.1.1:/usr/proj/recsw/
The reason for these particular destinations, is that the partly installed RTLinux on the
robot previously used these paths (see /usr/src/rtserd/rtl.mk). Now, the kernel source
files must be patched in order for RTLinux to work. This is done by issuing the following
command:
patch -p1 < /usr/src/kernel /usr/proj/recsw/<rtlinux_dir>/patches/<kernel_matching_patch>
Having patched the kernel, it must now be configured. This is done by issuing the following command from within the Linux source folder:
cd /usr/src/linux make menuconfig
