stack, even if we don't yet print it out.
At some point, vsprintf() needs to be fixed up so that it can correctly
cope with limited-sized buffers (i.e. vsnprintf), long longs, and
standard format specifiers (e.g. "%04x"). We should also remove the
special types (MAC addresses and IP addresses). This would then enable
us to use gcc's ability to type-check printf format strings.
us to return proper PXE status codes, while simultaneously allowing for
more consistent error reporting (complete with verbose error messages as a
build-time option).