image file.

ISA 3c509 is currently non-functional, although the EISA (3c509-eisa) and
MCA (3c529) variants should build OK.

None of this code is yet tested.

clean separation between loading and starting, but does mean that more
PXE stacks survive the process.

Added basic El Torito ISO image boot capability

provided by the divl instruction.

version.

somewhat redundant, and also causes gas to complain when we include
the profiling code (which uses an i586 instruction).

reflect the fact that they allocate and deallocate user memory (i.e.
things reached through a userptr_t).

doesn't want to go to the hassle of processing a full memory map.

initrds.

Parse command line for "vga=" and "mem=" parameters

Add a path for isolinux.bin that is correct on my system; hopefully it
will work on others too.

Move pxe_boot() code to pxe_image.c

Shut down before jumping to the multiboot image.

do it.

set_fbms() will also update the E820 hidden region.

to start on a non-page boundary.  Make life safer by rounding out our
edited regions.

Add IMAGE_PXE to use the new image format framework.  "kernel pxelinux.0"
now works.

don't overwrite the parameter block until *after* the debug code.

clue what the "previous" interrupt handler will do, which could range
from "just an iret" to "disable the interrupt"), and that means that
we have to take responsibility for ACKing all interrupts.  Joy.

allocation.

if we don't.

address, to work around OS bugs.