com32/lib/syslinux/shuffle_pm.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2007-2009 H. Peter Anvin - All Rights Reserved
   4  *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
   5  *
   6  *   Permission is hereby granted, free of charge, to any person
   7  *   obtaining a copy of this software and associated documentation
   8  *   files (the "Software"), to deal in the Software without
   9  *   restriction, including without limitation the rights to use,
  10  *   copy, modify, merge, publish, distribute, sublicense, and/or
  11  *   sell copies of the Software, and to permit persons to whom
  12  *   the Software is furnished to do so, subject to the following
  13  *   conditions:
  14  *
  15  *   The above copyright notice and this permission notice shall
  16  *   be included in all copies or substantial portions of the Software.
  17  *
  18  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  20  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  22  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  25  *   OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  * ----------------------------------------------------------------------- */
  28
  29 /*
  30  * shuffle_pm.c
  31  *
  32  * Shuffle and boot to protected mode code
  33  */
  34
  35 #include <inttypes.h>
  36 #include <syslinux/movebits.h>
  37 #include <syslinux/bootpm.h>
  38
  39 int syslinux_shuffle_boot_pm(struct syslinux_movelist *fraglist,
  40                              struct syslinux_memmap *memmap,
  41                              uint16_t bootflags, struct syslinux_pm_regs *regs)
  42 {
  43     uint8_t handoff_code[9 * 5], *p;
  44     const uint32_t *rp;
  45     int i, rv;
  46     struct syslinux_memmap *tmap;
  47     addr_t regstub, stublen;
  48
  49     tmap = syslinux_target_memmap(fraglist, memmap);
  50     if (!tmap)
  51         return -1;
  52
  53     regstub = 0x800;            /* Locate anywhere above this point */
  54     stublen = sizeof handoff_code;
  55     rv = syslinux_memmap_find_type(tmap, SMT_FREE, &regstub, &stublen, 1);
  56     syslinux_free_memmap(tmap);
  57     if (rv)
  58         return -1;
  59
  60     /* Build register-setting stub */
  61     p = handoff_code;
  62     rp = (const uint32_t *)regs;
  63     for (i = 0; i < 8; i++) {
  64         *p = 0xb8 + i;          /* MOV gpr,imm32 */
  65         *(uint32_t *) (p + 1) = *rp++;
  66         p += 5;
  67     }
  68     *p = 0xe9;                  /* JMP */
  69     *(uint32_t *) (p + 1) = regs->eip - regstub - sizeof handoff_code;
  70
  71     /* Add register-setting stub to shuffle list */
  72     if (syslinux_add_movelist(&fraglist, regstub, (addr_t) handoff_code,
  73                               sizeof handoff_code))
  74         return -1;
  75
  76     return syslinux_do_shuffle(fraglist, memmap, regstub, 1, bootflags);
  77 }