cpu tests are tests consisting of compiled mips code that run on the
R4300 + bcp.  to run the tests you need a working cpu simulator (sim.cpu)
and a compiled test.  As part of the build process, the test code is
converted from an elf file to an ascii file to be read into simulated
boot rom as part of simulator initialization.  The script 'cpusim' runs
a single test program, e.g.,

./cpusim -f mi/sane.dat