arch/x86/boot/voyager.c

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright (C) 1991, 1992 Linus Torvalds
   4  *   Copyright 2007 rPath, Inc. - All Rights Reserved
   5  *
   6  *   This file is part of the Linux kernel, and is made available under
   7  *   the terms of the GNU General Public License version 2.
   8  *
   9  * ----------------------------------------------------------------------- */
  10
  11 /*
  12  * arch/i386/boot/voyager.c
  13  *
  14  * Get the Voyager config information
  15  */
  16
  17 #include "boot.h"
  18
  19 int query_voyager(void)
  20 {
  21         u8 err;
  22         u16 es, di;
  23         /* Abuse the apm_bios_info area for this */
  24         u8 *data_ptr = (u8 *)&boot_params.apm_bios_info;
  25
  26         data_ptr[0] = 0xff;     /* Flag on config not found(?) */
  27
  28         asm("pushw %%es ; "
  29             "int $0x15 ; "
  30             "setc %0 ; "
  31             "movw %%es, %1 ; "
  32             "popw %%es"
  33             : "=q" (err), "=r" (es), "=D" (di)
  34             : "a" (0xffc0));
  35
  36         if (err)
  37                 return -1;      /* Not Voyager */
  38
  39         set_fs(es);
  40         copy_from_fs(data_ptr, di, 7);  /* Table is 7 bytes apparently */
  41         return 0;
  42 }