I got it fixed! Just used a USB with the image files and everything works.
As far as I can tell JamVM 1.5.4 works on the SBC1, but I'm not sure if there is a performance loss by my disabling of TLS in the compilation.
Apparently, the newest version of uClibc does have TLS support; however, I did not get the new version correctly configured in the build process.
Thanks for your help!