libfxcg | helper library for the Casio FX

It is infeasible to document how to set up your compiler on many platforms, but the basic requirement is that you have a version of GCC built to target sh3eb-elf-none. When building code, you'll need to use the -mb, -m4a-nofpu, -mhitachi and -nostdlib flags to GCC to build code in big-endian mode for SH4a using the Hitachi calling convention, and skipping any C library or startup code that may come with your compiler. When linking, you'll need to explicitly link libgcc and libfxcg at least, and optionally also libc for utility functions. libgcc provides support functions that the compiler requires, and libfxcg includes all of the Prizm-specific items, including startup code necessary to start up a program correctly. When linking a final binary, you will also need to specify an appropriate linker script (-Tscript.x). You may wish to use or adapt the one we provide.