=== Download a prepared Image ===

You can download the finished images here: [[ChumbyImageDownload]].

=== Build an Image on your own ===

Some daemons need to be compiled on another host machine, since the Chumby is not powerful enough for this task (and has not enough memory). Here are my notes:
====== Install Scratchbox ======
[[http://wiki.chumby.com/mediawiki/index.php/Scratchbox|as described here.]] This greatly simplifies cross-compiling things. It also provides you a way to run the compiled ruby interpreter on a bigger host machine using QEMU. This is essential because I rely on rubygems, and the Chumby is too small to execute the gem install commands. Besides, at least for the sqlite3-ruby and mongrel gems, I need to compile native code.

The CMake tool does not compile in a Scratchbox environment, see [[http://www.staerk.de/thorsten/Nokia_N810#cmake]]:
the error msg is
<code>
make[2]: *** No rule to make target `Source/CMakeFiles/CMakeLib.dir/link.txt', needed by `Source/libCMakeLib.a'.  Stop.
</code>
Workaround: I took link.txt from another computer and copied it => cmake is installed on the N810

The complete command sequence is:
<code>
mkdir build
cd build
../bootstrap --prefix=/mnt/storage/usr && make
# make install also fails, so:
cp bin/* /mnt/storage/usr/bin
</code>

====== Install dependencies ======
I found the following libraries necessary:
    - OpenSSL 0.9.8n – avoid the 1.0.0 version, it causes problems with the Ruby interpreter.
    - Zlib 1.5.3 – same as installed on the Chumby.
    - Readline 6.1
    - A recent version of sqlite, since I need it for my gems later on.
    Compile the libraries and install them into /mnt/storage (use –-prefix where necessary). 
====== Adjust the environment ======
to use the new libraries:
<code>
BASEDIR=/mnt/storage/usr
export PATH=$PATH:$BASEDIR/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$BASEDIR/lib
</code>
====== Install Ruby and rubygems ======
 I was not able to compile Ruby 1.8.7, but Ruby 1.8.6-p399 works nice. To configure everything, I use the following commands:
<code>
export ac_cv_func_getpgrp_void=yes
export ac_cv_func_setpgrp_void=yes
./configure --target=arm-linux --host=arm-linux --disable-pthread --enable-wide-getaddrinfo --enable-zlib --with-zlib-dir=/mnt/storage/usr --enable-readline --with-readline-dir=/mnt/storage/usr --prefix=/mnt/storage/usr --with-openssl-dir=/mnt/storage/usr && make && make install
</code>
Install rubygems:
<code>
/mnt/storage/usr/bin/ruby setup.rb --prefix=/mnt/storage/usr
mkdir -p /mnt/storage/usr/lib/ruby/gems/1.8
</code>
Afterwards, the necessary gems can be installed using the gem command. It might be necessary to provide additonal path information to the gems that compile native extensions, for example
<code>
gem install sqlite3-ruby -- --with-sqlite3-dir=/mnt/storage/usr
</code>


====== The result ======
is an image with Ruby installed, and all necessary gems for my project. The tarball can be downloaded here. To install, scp it to the Chumby and log in:
<code>
scp *tarball* root@*chumby-ip*:/mnt/storage
ssh -l root *chumby-ip*
cd /mnt/storage
tar xvzf *tarball*
</code>
Now you have a directory /mnt/storage/usr with all tools permanently installed on your Chumby. In order to use it, please adjust your PATH and LD_LIBRARY_PATH appropriately:
<code>
export BASEDIR=/mnt/storage/usr
export PATH=$PATH:$BASEDIR/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$BASEDIR/lib
</code>