Sir
you can check if units for your target OS-CPU exist,
(sample for i386-freebsd OS-CPU target)
for freepascal-> codetyphon\fpc\units\i386-freebsd
for lazarus -> codetyphon\lazarus\lcl\units\i386-freebsd
look at picture
For every "cannot find -lpthread" from target OS-CPU id.exe
you must copy from a real freebsd PC the "pthread.so" file
to fpc/bin/i386-freebsd folder
"cannot find -lxxx1" copy xxx1.so
"cannot find -lxxx2" copy xxx2.so
etc
Target OS-CPU linker(i386-freebsd-id.exe) try to find
these libraries
for Android you must install Android NDK to your PC
Please, don't forget that Cross-Build ability/capability
is a new software technology
not from a Theoretical point of view
but from real programmer's point of view