Updated PXE API dispatcher to use copy_{to,from}_user, and moved to
arch/i386 since the implementation is quite architecture-dependent.
(The individual PXE API calls can be largely
architecture-independent.)

--nulltrap to the make target at the moment.)

as a result of our memory map editing, so strip out any empty regions.

Allow our functions to return a non-zero, non-error status (since the
INT 13 Extensions Check has to return the API version in the register
that is otherwise always used for the error code).

Report a non-zero API version from the INT 13 Extensions Check; GRUB
now uses extended reads.

being noticed...

flow of control through this code.

We now always add PCI and PnP headers even for ISA ROMs; there's no harm
in doing so.

UNDI loader is still missing.

on the stack.

worrying about its stack being destroyed during the Etherboot run.

install() now calls relocate(), moves the protected-mode code to the new
location, and calls hide_etherboot().

Change semantics; relocate() now just finds a suitable location; it
doesn't actually perform the relocation itself.  Code in libprefix does
the copy in flat real mode.

order?

requiring each caller to decide how many entries it wants to permit.

REAL_CODE() don't need it.

int13_boot() now does its own segment register save and restore, ready
for the removal of segment register restoration from the libkir
generic code.

Ignore carry flag for INT 15,88; the Ralf Brown interrupt list says
that CF is unreliable for this call.

completely.

the only one we actually use).  This allows REAL_EXEC fragments to
contain proper references to constraints (e.g. "%w0"), rather than having
to force the use of specific registers.

Note that the "num_constraints" parameter is now completely obsolete, and
that we can probably reduce the syntax to something like
  __asm__ __volatile__ ( REAL_CODE ( "asm statements" )
                         : output constraints
                         : input constraints
                         : clobber );
which would look much more natural, and avoid the need to always specify
a clobber list.


Add userptr_t to libkir.h, to allow it to at least compile.

and creating a memory map that's easier to work with than the E820 map.

down to base memory, since it is now in the base-memory-resident
.text16 section).

usual __{text,data}16 trick work with arrays.  gcc seems to accept the
__asm__ ( asmlabel ) only after the [] of the array declaration, not
before.

We now split e820 regions around ourselves, rather than just
truncating the e820 region.  This avoids the worst-case scenario of
losing all memory over 4GB.

It's more important to get the memory map right now that we're
expecting to still be loaded when the OS starts in several situations
(e.g. Linux with UNDI driver, any OS with iSCSI/AoE boot, etc.).

Tidied up debug messages; the log now contains one line per INT 13
operation, looking like

 INT 13,08 (80): Get drive parameters
 INT 13,02 (80): Read: C/H/S 0/47/14 = LBA 0xb9e <-> 1084:0000 (count 106)