Additional stylistic cleanups.  Rename "syscall" to "intcall" (we
can't call it __intcall without clashing with com32.h); use macros
instead of copying variables to different places with only the type
being different.

Also, only change the rm/pm jump instructions when actually relocating
the code.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Minor cleanups to the source base; make die() also print an error
message and move die() into conio.c.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Relocate the real-mode code before booting.  This allows the target
bootstrap to be loaded at an arbitrary address, not necessarily
0x7c00, and to be almost arbitrarily long.

Add some initial infrastructure for other bootstrap addresses, too.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Move the rm_args initialization (and the associated sti) to C code.
Export the total size of the real-mode code to the protected-mode
code.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Pass in the address of the real-mode code instead of hard-coding it in
two separate places.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Automatically reformat memdisk/memdisk.h using Nindent.

Do this for all files except HDT, gPXE and externally maintained
libraries (zlib, tinyjpeg, libpng).

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Cleanup and centralize the Makefile system even more.
Fix a gcc 4.3 incompatibility in memdisk (definition of strlen).

Per the Interrupt list, treat INT 13 08 returning with CL=0 as a
failure, meaning single drive only.

If we find ourselves the only floppy drive, install a DPT into INT
1Eh.  This appears to be needed for PC-DOS 7.0 to boot.  This can be
overridden with the "nodpt" option, and forced with the "dpt" option.

Use the aligning memcpy/memset from libcom32.  Switch memdisk to
compiling with -mregparm=3, except for the interfaces to assembly.