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  * Get the Voyager config information
  13  */
  14
  15 #include "boot.h"
  16
  17 int query_voyager(void)
  18 {
  19         u8 err;
  20         u16 es, di;
  21         /* Abuse the apm_bios_info area for this */
  22         u8 *data_ptr = (u8 *)&boot_params.apm_bios_info;
  23
  24         data_ptr[0] = 0xff;     /* Flag on config not found(?) */
  25
  26         asm("pushw %%es ; "
  27             "int $0x15 ; "
  28             "setc %0 ; "
  29             "movw %%es, %1 ; "
  30             "popw %%es"
  31             : "=q" (err), "=r" (es), "=D" (di)
  32             : "a" (0xffc0));
  33
  34         if (err)
  35                 return -1;      /* Not Voyager */
  36
  37         set_fs(es);
  38         copy_from_fs(data_ptr, di, 7);  /* Table is 7 bytes apparently */
  39         return 0;
  40 }