Maybe a more general question would be: what is our main build entry point? Is it `make` (or `make all`) still, or is it meson now?
For this specific optionrom thing, I'd say we should add a separate rule to the top-level Makefile (or to meson.build) which is not run by default but can be run explicitly, like `make optionrom` - this will check if pc-bios/optionrom/config.mak is there and either run make in this subdir or complain saying no i386 compiler is found. Thanks, /mjt
