implement the -e option.

(Thanks to Jim McQuillan for this suggestion.)

inside gPXE.

Experimentation reveals that gcc ignores -mrtd for the implicit
arithmetic functions (e.g. __udivdi3), but not for the implicit
memcpy() and memset() functions.  Mark the implicit arithmetic
functions with __attribute__((cdecl)) to compensate for this.

(Note: we cannot mark with with __cdecl, because we define __cdecl to
incorporate regparm(0) as well.)

Even though it is only currently used for rom-o-matic.net code,
it is good to make sure it gets built, and that the parsing code
is working.

bin/%.bin target.

This reverts commit 9dc2515d7e.

I want "make" to actually build something.

"boot" command to attempt booting from within the command shell, fall back
to shell if boot fails for any reason.

used on RTL8139 cards).

Avoid including debug information in bin/%.s output, since the whole
point is to have easy-to-read assembler.

-Obinary build anyway, so it doesn't waste any space).

moment.

when make is invoked without arguments

directory.