As on the left side off this forum (Downloads Laz+Fpc)
http://sourceforge.net/project/showfiles.php?group_id=89339The addons only come for Windows, to allow 32/64 bit windows cross compiling (you need to choose the correct addon, based on if your IDE is 64 or 32 bit). The add on is in the same folder as the IDE installer.
Be aware that before version 2.0RC3 the add on does not ask for the path. It uses the path of the primary Lazarus install (in case you have 2ndary installs)
The add on contains the cross compiler, and a gdb version for the correct bitness.
As for the config.
If you do not want to reset your entire config, the default value for the dbg path is
$(LazarusDir)\mingw\$(TargetCPU)-$(TargetOS)\bin\gdb.exe
So if you already have cross compilers, and gdb versions then you just have to put them in the correct folders in your install dir
E.g:
C:\lazarus\mingw\i386-win32\bin\
C:\lazarus\mingw\x86_64-win64\bin\
You can change the path to suit your install layout. So long as target cpu and/or os appear in either the path or filename.