I don't have enough free time at the moment to study closely your problem, but here
are some links :
official dowload page :
click the green download link
ignore the ad and reduce the length of the url to match : "http://sourceforge.net/projects/openxdk/files/"
refresh your browser with that reduced URL to see all existing files
pre-compiled binaries (including libSDL.a) :http://minilgos.perso.sfr.fr/openxdk.zip
the secret is all in the way you start compiling and what the makefile has inside
usually i modify the makefile to add some infos about rules to use
try some sample such as oggdec, pbkit demos etc...
follow the links below and look inside makefiles of samples
(I don't remember details, warn us if you are still blocked)http://minilgos.perso.sfr.fr/pbkit/changelog.txt
(see a few links to tutorials hosted by x-s forums at bottom)