sys/arch/hp700/include/nvm.h

   1 /*      $NetBSD: nvm.h,v 1.1 2002/06/06 19:48:09 fredette Exp $ */
   2
   3 /*      $OpenBSD: nvm.h,v 1.2 1998/11/23 03:28:22 mickey Exp $  */
   4
   5 /*
   6  * Copyright (c) 1990, 1994 The University of Utah and
   7  * the Computer Systems Laboratory at the University of Utah (CSL).
   8  * All rights reserved.
   9  *
  10  * Permission to use, copy, modify and distribute this software is hereby
  11  * granted provided that (1) source code retains these copyright, permission,
  12  * and disclaimer notices, and (2) redistributions including binaries
  13  * reproduce the notices in supporting documentation, and (3) all advertising
  14  * materials mentioning features or use of this software display the following
  15  * acknowledgement: ``This product includes software developed by the
  16  * Computer Systems Laboratory at the University of Utah.''
  17  *
  18  * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
  19  * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
  20  * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  21  *
  22  * CSL requests users of this software to return to csl-dist@cs.utah.edu any
  23  * improvements that they make and grant CSL redistribution rights.
  24  *
  25  *      Utah $Hdr: nvm.h 1.4 94/12/14$
  26  *      Author: Jeff Forys, University of Utah CSL
  27  */
  28
  29 #ifndef _MACHINE_NVM_H_
  30 #define _MACHINE_NVM_H_
  31
  32 /*
  33  * The PDC provides access to Non-Volatile Memory (NVM).  If this
  34  * is implemented (it's HVERSION dependent), the first 256 bytes
  35  * are formatted as follows:
  36  *
  37  *      0x000   +----------------------------+
  38  *              | Implementation information |
  39  *      0x024   +----------------------------+
  40  *              |                            |
  41  *              |      IPL information       |
  42  *              |                            |
  43  *      0x080   +----------------------------+
  44  *              |                            |
  45  *              |                            |
  46  *              |    OS Panic information    |
  47  *              |                            |
  48  *              |                            |
  49  *      0x100   +----------------------------+
  50  *
  51  * It appears that there are at least 256 bytes of NVM, and only
  52  * the "OS Panic information" is not architected.  This means that
  53  * we can use locations 0x80 - 0xFF for saving information across
  54  * boots (e.g. boot flags and boot device).  I think we should use
  55  * the higher portions of this space first, to avoid conflicting
  56  * with possible future HP-PA plans for the NVM.
  57  *
  58  * The PDC requires that NVM be read/written to in word multiples.
  59  */
  60
  61 /*
  62  * Boot flags and boot device (0xF4 - 0xFF).
  63  */
  64
  65 #define NVM_BOOTDATA    0xF4            /* location of bootdata in NVM */
  66 #define NVM_BOOTMAGIC   0xACCEDE        /* magic used for bootdata cksum */
  67 #define NVM_BOOTCKSUM(bd) \
  68         ((unsigned int) NVM_BOOTMAGIC + (bd).flags + (bd).device)
  69
  70 struct bootdata {
  71         unsigned int cksum;             /* NVM_BOOTMAGIC + flags + device */
  72         unsigned int flags;             /* boot flags */
  73         unsigned int device;            /* boot device */
  74 };
  75
  76 #endif  /* _MACHINE_NVM_H_ */