Cross-compiling didn't work for me either mainly because you need a handful of Linux libraries from Raspberry PI for linking. You may try getting precompiled one from
Thaddy's web site.
Compiling from SVN sources on Raspberry PI works, but now you won't be able to obtain FPC on latest Raspbian image without some effort due to conflicting packages. Steps that worked for me was to uninstall "binutils", install "binutils" version 2.22-8, install FPC 2.6.0 (this is not needed, but it also installs a lot of packages that later will be needed for Lazarus), download
Thaddy precompiled armhf binaries, with that compile FPC from trunk SVN (rev 28812 or earlier because of
this issue) and then compile Lazarus from trunk SVN. Also, for this to work, you'll need to reallocate GPU memory to 16 Mb and increase swap size to around 1 Gb.