chibi-ffi reads in the C function FFI definitions from an input file and outputs
the appropriate C wrappers into a file with the same base name and the
".c" extension. You can then compile that C file into a shared
cc -fPIC -shared file.c -lchibi-scheme
If the -c option is specified then chibi-ffi attempts to compile the
generated C code for you in one step. In this case, additional flags
for the C compiler may be given with the -f option.
The FFI syntax is described in the manual.