root/sys/arch/amd64/isa/nvram.h
/*      $OpenBSD: nvram.h,v 1.1 2007/08/02 16:40:27 deraadt Exp $       */
/*      $NetBSD: nvram.h,v 1.5 1995/05/05 22:08:43 mycroft Exp $        */

/*-
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)rtc.h       8.1 (Berkeley) 6/11/93
 */

/*
 * The following information is found in the non-volatile RAM in the
 * MC146818A (or DS1287A or other compatible) RTC on AT-compatible PCs.
 */

/* NVRAM byte 0: bios diagnostic */
#define NVRAM_DIAG      (MC_NVRAM_START + 0)    /* RTC offset 0xe */

#define NVRAM_DIAG_BITS         "\020\010clock_battery\007ROM_cksum\006config_unit\005memory_size\004fixed_disk\003invalid_time"

/* NVRAM byte 1: reset code */
#define NVRAM_RESET     (MC_NVRAM_START + 1)    /* RTC offset 0xf */

#define NVRAM_RESET_RST         0x00            /* normal reset */
#define NVRAM_RESET_LOAD        0x04            /* load system */
#define NVRAM_RESET_JUMP        0x0a            /* jump through 40:67 */

/* NVRAM byte 2: diskette drive type in upper/lower nibble */
#define NVRAM_DISKETTE  (MC_NVRAM_START + 2)    /* RTC offset 0x10 */

#define NVRAM_DISKETTE_NONE      0              /* none present */
#define NVRAM_DISKETTE_360K      0x10           /* 360K */
#define NVRAM_DISKETTE_12M       0x20           /* 1.2M */
#define NVRAM_DISKETTE_720K      0x30           /* 720K */
#define NVRAM_DISKETTE_144M      0x40           /* 1.44M */
#define NVRAM_DISKETTE_TYPE5     0x50           /* 2.88M, presumably */
#define NVRAM_DISKETTE_TYPE6     0x60           /* 2.88M */

/* NVRAM byte 6: equipment type */
#define NVRAM_EQUIPMENT (MC_NVRAM_START + 6)

#define NVRAM_EQUIPMENT_FLOPPY  0x01            /* floppy installed */
#define NVRAM_EQUIPMENT_FPU     0x02            /* FPU installed */
#define NVRAM_EQUIPMENT_KBD     0x04            /* keyboard installed */
#define NVRAM_EQUIPMENT_DISPLAY 0x08            /* display installed */
#define NVRAM_EQUIPMENT_EGAVGA  0x00            /* EGA or VGA */
#define NVRAM_EQUIPMENT_COLOR40 0x10            /* 40 column color */
#define NVRAM_EQUIPMENT_COLOR80 0x20            /* 80 column color */
#define NVRAM_EQUIPMENT_MONO80  0x30            /* 80 column mono */
#define NVRAM_EQUIPMENT_MONITOR 0x30            /* mask for monitor type */
#define MVRAM_EQUIPMENT_NFDS    0xC0            /* mask for # of floppies */

/* NVRAM bytes 7 & 8: base memory size */
#define NVRAM_BASELO    (MC_NVRAM_START + 7)    /* low byte; RTC off. 0x15 */
#define NVRAM_BASEHI    (MC_NVRAM_START + 8)    /* high byte; RTC off. 0x16 */

/* NVRAM bytes 9 & 10: extended memory size */
#define NVRAM_EXTLO     (MC_NVRAM_START + 9)    /* low byte; RTC off. 0x17 */
#define NVRAM_EXTHI     (MC_NVRAM_START + 10)   /* high byte; RTC off. 0x18 */

/* NVRAM bytes 34 and 35: extended memory POSTed size */
#define NVRAM_PEXTLO    (MC_NVRAM_START + 34)   /* low byte; RTC off. 0x30 */
#define NVRAM_PEXTHI    (MC_NVRAM_START + 35)   /* high byte; RTC off. 0x31 */

/* NVRAM byte 36: current century.  (please increment in Dec99!) */
#define NVRAM_CENTURY   (MC_NVRAM_START + 36)   /* RTC offset 0x32 */