[ros-users] Ros on Gumstix: another way of doing it...

[Radu Bogdan Rusu]

Cedric,

Thanks for sharing your experiences with ROS on gumstix! There's a lot of valuable information here, and in order for it 
to "live on", would you mind setting up a wiki page? I know there's other people out there working on the same thing, so 
if we could centralize this information, that would be great! :) Thank you in advance.

Cheers,
Radu.

Cedric Pradalier wrote:
> Hi all,
> 
> I have been spending some effort on making ROS compiling for the gumstix 
> and I'd like to share the experience:
> 
> First of all, I have tried the approach listed on the wiki, and they are 
> not my favourite but they provide a good basis.
> 
> The first thing I have done is installing ubuntu on the gumstix (a guide 
> for that can be found on 
> http://johnwoconnor.blogspot.com/2009/04/installing-ubuntu-on-gumstix-overo.html)
> This simplifies a lot the process of getting all the 3rd party libraries 
> compiled (in particular boost, xmlrpc++, log4cxx, apr can then just be 
> obtained using an apt-get call).
> 
> Once you have installed ubuntu on the gumstix, you could in theory 
> install all the -dev packages and gcc/g++ and compile everything 
> natively. Needless to say that it might be a little bit long given the 
> performances of the gumstix. However, this is a working solution.
> 
> The second solution is to run a gumstix image using qemu and in 
> particular qemu-system-arm (package qemu-kvm-extras in ubuntu 9.10). To 
> this end, you first need to setup a disk image, mount it, copy the file 
> system created using the link above.
> #> qemu-img create overo-ros.img 2G
> #> mkdir overo-ros
> #> mount -o loop overo-ros.img overo-ros
> #> cd overo-ros
> #> sudo tar -zxvf /path/to/armel-rootfs-YYYYMMDDhhmm.tgz
> 
> At this point the file system can be umounted and launched with qemu 
> (get the kernel by following the instruction at 
> http://people.canonical.com/~ogra/arm/qemu/README)
> 
> #> umount overo-ros
> #> sudo qemu-system-arm -M versatilepb -kernel vmlinuz-2.6.28-versatile 
> -hda overo-ros.img -m 256M -append "root=/dev/sda" -net nic -net user
> 
> I have not tried booting the image while it is still mounted. I suspect 
> it does not work so well.
> 
> Once qemu has started the image, one can easily apt-get arm packages and 
> update the image to get all the -dev packages. It is also possible to 
> install gcc and compile all ros in the virtual gumstix. However, this 
> takes forever, even longer than on the real system.
> 
> However, getting qemu running is not a loss of time. Once all the -dev 
> packets have been installed, the ubuntu image can be used to 
> cross-compile. To this end, I first quit qemu, and remount overo-ros.
> 
> The following will assume you have a a cross compiler installed, for 
> instance through buildroot or open-embedded (check the gumstix wiki). We 
> can then use the -sysroot option of gcc to compile using the overo-ros 
> directory as the root of the filesystem (where /usr/include and /usr/lib 
> are looked for). However, at the time of this writing libtool is not 
> able to pass a -sysroot option to gcc, so I write a set of scripts for 
> gcc, g++ and cpp, respectively called gcc-sysroot, g++-sysroot, and 
> cpp-sysroot. The scripts are as follows:
>  
>  #!/bin/bash
>  if test -n "$ARM_SYSROOT"
>  then
>     SYSROOT=--sysroot=$ARM_SYSROOT
>  fi
>  exec ${0/-sysroot/} $SYSROOT $*
> 
> The same script can be used for all the executable as it find which 
> binary to call based on how it was called.
> 
> Once the scripts are defined, I have a special gumstix compilation 
> environment:
>  export GUMSTIXTOP=$HOME/overo-oe/
>  export OVEROROOT=$HOME/overobuntu/overo-ros
>  export 
> PKG_CONFIG_PATH=$OVEROROOT/usr/local/lib/pkgconfig:$OVEROROOT/usr/lib/pkgconfig
> 
>  export ARM_SYSROOT=$OVEROROOT
>  export CROSSBIN=$GUMSTIXTOP/tmp/cross/armv7a/arm-angstrom-linux-gnueabi/bin
>  export PATH=$CROSSBIN:$PATH
>  export AR=$CROSSBIN/ar
>  export CPP=$CROSSBIN/cpp-sysroot
>  export CXX=$CROSSBIN/g++-sysroot
>  export CC=$CROSSBIN/gcc-sysroot
> 
> 
> Once this is sourced in the current shell, you can call rosmake 
> normally, and everything should be able to compile. Obviously, rosdep 
> install does not work (you have to restart the qemu thing and call 
> apt-get from there, or at least that the easy solution I found). I have 
> all the laser and image processing stack working in particular, even 
> libdc1394 with the usb drivers for the pointgrey cameras.
> 
> Please note that you need to recall "cmake ." in all the directories. 
> This can be done for instance with a script such as: (not fully tested)
> 
>  roscd
>  find . -name "CMakeCache.txt" | while read line
>  do 
>      cd ${line/build\/CMakeCache.txt/}
>      cmake .
>      cd -
>  done
> 
> Beware that a couple of binary must be compiled native and crossed 
> (rospack, rosstack and rosmsg). To this end, compile them first native, 
> save them (for instance renaming it rospack.intel), then compile them 
> crossed, save the crossed compilation for later installation (for 
> instance renaming it rospack.arm), then make a link to the correct 
> executable for the current architecture, and mark these directory 
> ROS_NOBUILD (touch ROS_NOBUILD). This also applies to libraries such as 
> librospack.so and librosstack.so. I hope the WillowGarage team finds a 
> way to decouple these libraries for cross-compilation.
> 
> It might also be necessary to delete all the .la files installed with 
> the -dev package in ubuntu on the arm image. These files refers libtool 
> to some libraries in /usr/include and /usr/lib, without using the 
> -sysroot option. gcc/g++ sees the risk and does not accept to compile 
> then. This is a problem in particular for libjpeg (compressed image 
> transport).
> 
> Using all the above, I have ros working on both the gumstix overo and 
> verdex. On the overo, using wifi G, the gumstix can downstream telemetry 
> data and video data from an helicopter, using either raw images or 
> jpeg-compressed images (not much framerate gain).
> 
> On the verdex, I need to change the timeout in rospy/client.py (TBC) to 
> 20seconds as it is the time the systems needs to get roscore up and 
> running (The disk access performance are extremely bad on this older 
> board). If someone wants to run ROS on a verdex, please contact me, and 
> I'll check exactly what I had to change to make it happen. Not that the 
> file system mentioned above works for a verdex.
> 
> Check on http://support.skybotix.com/downloads.php for a full filesystem 
> for the gumstix overo, with ros pre-compiled (Skybotix is a company 
> selling micro-helicopter with an embedded gumstix, but the file system 
> should be a good starting point for any gumstix application)
> 
> I hope all this information helps...
> 

-- 
| Radu Bogdan Rusu | http://rbrusu.com/