Here are some SPC loader tests I just finished: spc_loader_tests.zip
They test that RAM is loaded properly, CPU registers, DSP registers, $F0-$FF, and that $F4-$F7 are restored before the first instruction can access them. The RAM tests do several regions separately, in case your loader patches it:
$00-$EF
$100-$1FF (ignores three bytes just under sp)
$200-$FFFF (excluding echo buffer)
Echo buffer
Three bytes just under sp
They test that RAM is loaded properly, CPU registers, DSP registers, $F0-$FF, and that $F4-$F7 are restored before the first instruction can access them. The RAM tests do several regions separately, in case your loader patches it:
$00-$EF
$100-$1FF (ignores three bytes just under sp)
$200-$FFFF (excluding echo buffer)
Echo buffer
Three bytes just under sp