1 /* $NetBSD: cmos.c,v 1.14 2023/12/20 15:00:07 thorpej Exp $ */ 2 3 /* 4 * Copyright (C) 2003 JONE System Co., Inc. 5 * All right reserved. 6 * 7 * Copyright (C) 1999, 2000, 2001, 2002 JEPRO Co., Ltd. 8 * All right reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 */ 33 /* 34 * Copyright (c) 2007 David Young. All right reserved. 35 * 36 * Redistribution and use in source and binary forms, with or 37 * without modification, are permitted provided that the following 38 * conditions are met: 39 * 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above 43 * copyright notice, this list of conditions and the following 44 * disclaimer in the documentation and/or other materials provided 45 * with the distribution. 46 * 47 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 48 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 49 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 50 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 51 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 52 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 53 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 54 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 55 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 56 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 57 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 */ 60 61 #include <sys/cdefs.h> 62 __KERNEL_RCSID(0, "$NetBSD: cmos.c,v 1.14 2023/12/20 15:00:07 thorpej Exp $"); 63 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/kernel.h> 67 #include <sys/ioctl.h> 68 #include <sys/proc.h> 69 #include <sys/device.h> 70 #include <sys/conf.h> 71 #include <sys/kauth.h> 72 73 #include <sys/bus.h> 74 #include <machine/intr.h> 75 76 #include <dev/isa/isareg.h> 77 #include <dev/isa/isavar.h> 78 #include <dev/ic/mc146818reg.h> 79 #include <i386/isa/nvram.h> 80 81 #include "ioconf.h" 82 83 #define CMOS_SUM 32 84 #define CMOS_BIOSSPEC 34 /* start of BIOS-specific configuration data */ 85 86 #define NVRAM_SUM (MC_NVRAM_START + CMOS_SUM) 87 #define NVRAM_BIOSSPEC (MC_NVRAM_START + CMOS_BIOSSPEC) 88 89 #define CMOS_SIZE NVRAM_BIOSSPEC 90 91 dev_type_open(cmos_open); 92 dev_type_read(cmos_read); 93 dev_type_write(cmos_write); 94 95 static void cmos_sum(uint8_t *, int, int, int); 96 97 const struct cdevsw cmos_cdevsw = { 98 .d_open = cmos_open, 99 .d_close = nullclose, 100 .d_read = cmos_read, 101 .d_write = cmos_write, 102 .d_ioctl = noioctl, 103 .d_stop = nostop, 104 .d_tty = notty, 105 .d_poll = nopoll, 106 .d_mmap = nommap, 107 .d_kqfilter = nokqfilter, 108 .d_discard = nodiscard, 109 .d_flag = D_OTHER | D_MPSAFE 110 }; 111 112 static kmutex_t cmos_lock; 113 static uint8_t cmos_buf[CMOS_SIZE]; 114 115 void 116 cmosattach(int n) 117 { 118 119 mutex_init(&cmos_lock, MUTEX_DEFAULT, IPL_NONE); 120 } 121 122 int 123 cmos_open(dev_t dev, int flags, int ifmt, struct lwp *l) 124 { 125 126 return kauth_authorize_machdep(l->l_cred, 127 KAUTH_MACHDEP_NVRAM, NULL, NULL, NULL, NULL); 128 } 129 130 static void 131 cmos_fetch(void) 132 { 133 int i, s; 134 uint8_t *p; 135 136 p = cmos_buf; 137 s = splclock(); 138 for (i = 0; i < CMOS_SIZE; i++) 139 *p++ = mc146818_read(NULL, i); 140 splx(s); 141 } 142 143 int 144 cmos_read(dev_t dev, struct uio *uio, int ioflag) 145 { 146 int error; 147 148 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE) 149 return EINVAL; 150 151 mutex_enter(&cmos_lock); 152 cmos_fetch(); 153 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio); 154 mutex_exit(&cmos_lock); 155 156 return error; 157 } 158 159 int 160 cmos_write(dev_t dev, struct uio *uio, int ioflag) 161 { 162 int error = 0, i, s; 163 164 if (uio->uio_offset + uio->uio_resid > CMOS_SIZE) 165 return EINVAL; 166 167 mutex_enter(&cmos_lock); 168 cmos_fetch(); 169 error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio); 170 if (error == 0) { 171 cmos_sum(cmos_buf, NVRAM_DISKETTE, NVRAM_SUM, NVRAM_SUM); 172 s = splclock(); 173 for (i = NVRAM_DISKETTE; i < CMOS_SIZE; i++) 174 mc146818_write(NULL, i, cmos_buf[i]); 175 splx(s); 176 } 177 mutex_exit(&cmos_lock); 178 179 return error; 180 } 181 182 static void 183 cmos_sum(uint8_t *p, int from, int to, int offset) 184 { 185 int i; 186 uint16_t sum; 187 188 #ifdef CMOS_DEBUG 189 printf("%s: from %d to %d and store %d\n", __func__, from, to, offset); 190 #endif 191 192 sum = 0; 193 for (i = from; i < to; i++) 194 sum += p[i]; 195 p[offset] = sum >> 8; 196 p[offset + 1] = sum & 0xff; 197 } 198
Indexes created Sat Sep 20 22:09:52 GMT 2025