Compiling C/C++ Programs For Embedded Linux -- Hello, World!

Put the toolchain's bin directory on your PATH, e.g.
    $ PATH=${PATH}:/mygcc/bin

Then instead of cc, use the cross-compiler to compile, e.g.
    $ ppc-405-linux-gnu-gcc hello.c

Projects using Makefiles can usually be compiled like this:
    $ make CC=ppc-405-linux-gnu-gcc
though you should read and understand the Makefile first.