1 /* $NetBSD: nvm.h,v 1.1 2014/02/24 07:23:43 skrll 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_ */ 77