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/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
 *
 *   Permission is hereby granted, free of charge, to any person
 *   obtaining a copy of this software and associated documentation
 *   files (the "Software"), to deal in the Software without
 *   restriction, including without limitation the rights to use,
 *   copy, modify, merge, publish, distribute, sublicense, and/or
 *   sell copies of the Software, and to permit persons to whom
 *   the Software is furnished to do so, subject to the following
 *   conditions:
 *
 *   The above copyright notice and this permission notice shall
 *   be included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *   OTHER DEALINGS IN THE SOFTWARE.
 *
 * ----------------------------------------------------------------------- */

/*
 * shuffle_pm.c
 *
 * Shuffle and boot to protected mode code
 */

#include <stdlib.h>
#include <inttypes.h>
#include <com32.h>
#include <string.h>
#include <syslinux/movebits.h>
#include <syslinux/bootpm.h>

int syslinux_shuffle_boot_pm(struct syslinux_movelist *fraglist,
			     struct syslinux_memmap *memmap,
			     uint16_t bootflags,
			     struct syslinux_pm_regs *regs)
{
  int nd;
  com32sys_t ireg;
  char *regbuf;
  uint8_t handoff_code[9*5], *p;
  const uint32_t *rp;
  int i, rv;
  struct syslinux_memmap *tmap;
  addr_t regstub, stublen, safe;

  tmap = syslinux_target_memmap(fraglist, memmap);
  if (!tmap)
    return -1;

  regstub = 0x800;		/* Locate anywhere above this point */
  stublen = sizeof handoff_code;
  rv = syslinux_memmap_find(tmap, SMT_FREE, &regstub, &stublen);
  syslinux_free_memmap(tmap);
  if (rv)
    return -1;

  /* Build register-setting stub */
  p = handoff_code;
  rp = (const uint32_t *)regs;
  for (i = 0; i < 8; i++) {
    *p = 0xb8 + i;		/* MOV gpr,imm32 */
    *(uint32_t *)(p+1) = *rp++;
    p += 5;
  }
  *p = 0xe9;			/* JMP */
  *(uint32_t *)(p+1) = regs->eip - regstub - sizeof handoff_code;

  /* Add register-setting stub to shuffle list */
  if (syslinux_add_movelist(&fraglist, regstub, (addr_t)handoff_code,
			    sizeof handoff_code))
    return -1;

  return syslinux_do_shuffle(fraglist, memmap, regstub, 1, bootflags);
}