Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 1 | /*****************************************************************************\ |
| 2 | * cmos_ops.c |
Uwe Hermann | 1a6177b | 2008-01-25 15:08:37 +0000 | [diff] [blame] | 3 | * $Id$ |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 4 | ***************************************************************************** |
| 5 | * Copyright (C) 2002-2005 The Regents of the University of California. |
| 6 | * Produced at the Lawrence Livermore National Laboratory. |
| 7 | * Written by David S. Peterson <dsp@llnl.gov> <dave_peterson@pobox.com>. |
| 8 | * UCRL-CODE-2003-012 |
| 9 | * All rights reserved. |
| 10 | * |
Uwe Hermann | 6e56594 | 2008-03-01 19:06:32 +0000 | [diff] [blame] | 11 | * This file is part of nvramtool, a utility for reading/writing coreboot |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 12 | * parameters and displaying information from the coreboot table. |
Uwe Hermann | 6e56594 | 2008-03-01 19:06:32 +0000 | [diff] [blame] | 13 | * For details, see http://coreboot.org/nvramtool. |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 14 | * |
| 15 | * Please also read the file DISCLAIMER which is included in this software |
| 16 | * distribution. |
| 17 | * |
| 18 | * This program is free software; you can redistribute it and/or modify it |
| 19 | * under the terms of the GNU General Public License (as published by the |
| 20 | * Free Software Foundation) version 2, dated June 1991. |
| 21 | * |
| 22 | * This program is distributed in the hope that it will be useful, but |
| 23 | * WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF |
| 24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and |
| 25 | * conditions of the GNU General Public License for more details. |
| 26 | * |
| 27 | * You should have received a copy of the GNU General Public License along |
| 28 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 29 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
| 30 | \*****************************************************************************/ |
| 31 | |
| 32 | #include "common.h" |
| 33 | #include "cmos_ops.h" |
| 34 | #include "cmos_lowlevel.h" |
| 35 | |
| 36 | static int prepare_cmos_op_common (const cmos_entry_t *e); |
| 37 | |
| 38 | /**************************************************************************** |
| 39 | * prepare_cmos_op_common |
| 40 | * |
| 41 | * Perform a few checks common to both reads and writes. |
| 42 | ****************************************************************************/ |
| 43 | static int prepare_cmos_op_common (const cmos_entry_t *e) |
| 44 | { int result; |
| 45 | |
| 46 | if (e->config == CMOS_ENTRY_RESERVED) |
| 47 | /* Access to reserved parameters is not permitted. */ |
| 48 | return CMOS_OP_RESERVED; |
| 49 | |
| 50 | if ((result = verify_cmos_op(e->bit, e->length)) != OK) |
| 51 | return result; |
| 52 | |
| 53 | assert(e->length > 0); |
| 54 | return OK; |
| 55 | } |
| 56 | |
| 57 | /**************************************************************************** |
| 58 | * prepare_cmos_read |
| 59 | * |
| 60 | * The caller wishes to read a CMOS parameter represented by 'e'. Perform |
| 61 | * sanity checking on 'e'. If a problem was found with e, return an error |
| 62 | * code. Else return OK. |
| 63 | ****************************************************************************/ |
| 64 | int prepare_cmos_read (const cmos_entry_t *e) |
| 65 | { int result; |
| 66 | |
| 67 | if ((result = prepare_cmos_op_common(e)) != OK) |
| 68 | return result; |
| 69 | |
| 70 | switch (e->config) |
| 71 | { case CMOS_ENTRY_ENUM: |
| 72 | case CMOS_ENTRY_HEX: |
| 73 | break; |
| 74 | |
| 75 | default: |
| 76 | BUG(); |
| 77 | } |
| 78 | |
| 79 | return OK; |
| 80 | } |
| 81 | |
| 82 | /**************************************************************************** |
| 83 | * prepare_cmos_write |
| 84 | * |
| 85 | * The caller wishes to set a CMOS parameter represented by 'e' to a value |
| 86 | * whose string representation is stored in 'value_str'. Perform sanity |
| 87 | * checking on 'value_str'. On error, return an error code. Else store the |
| 88 | * numeric equivalent of 'value_str' in '*value' and return OK. |
| 89 | ****************************************************************************/ |
| 90 | int prepare_cmos_write (const cmos_entry_t *e, const char value_str[], |
| 91 | unsigned long long *value) |
| 92 | { const cmos_enum_t *q; |
| 93 | unsigned long long out; |
| 94 | const char *p; |
| 95 | int negative, result, found_one; |
| 96 | |
| 97 | if ((result = prepare_cmos_op_common(e)) != OK) |
| 98 | return result; |
| 99 | |
| 100 | switch (e->config) |
| 101 | { case CMOS_ENTRY_ENUM: |
| 102 | /* Make sure the user's input corresponds to a valid option. */ |
| 103 | for (q = first_cmos_enum_id(e->config_id), found_one = 0; |
| 104 | q != NULL; |
| 105 | q = next_cmos_enum_id(q)) |
| 106 | { found_one = 1; |
| 107 | |
| 108 | if (!strncmp(q->text, value_str, CMOS_MAX_TEXT_LENGTH)) |
| 109 | break; |
| 110 | } |
| 111 | |
| 112 | if (!found_one) |
| 113 | return CMOS_OP_NO_MATCHING_ENUM; |
| 114 | |
| 115 | if (q == NULL) |
| 116 | return CMOS_OP_BAD_ENUM_VALUE; |
| 117 | |
| 118 | out = q->value; |
| 119 | break; |
| 120 | |
| 121 | case CMOS_ENTRY_HEX: |
| 122 | /* See if the first character of 'value_str' (excluding any initial |
| 123 | * whitespace) is a minus sign. |
| 124 | */ |
| 125 | for (p = value_str; isspace(*p); p++); |
| 126 | negative = (*p == '-'); |
| 127 | |
| 128 | out = strtoull(value_str, (char **) &p, 0); |
| 129 | |
| 130 | if (*p) |
| 131 | return CMOS_OP_INVALID_INT; |
| 132 | |
| 133 | /* If we get this far, the user specified a valid integer. However |
| 134 | * we do not currently support the use of negative numbers as CMOS |
| 135 | * parameter values. |
| 136 | */ |
| 137 | if (negative) |
| 138 | return CMOS_OP_NEGATIVE_INT; |
| 139 | |
| 140 | break; |
| 141 | |
| 142 | default: |
| 143 | BUG(); |
| 144 | } |
| 145 | |
| 146 | if ((e->length < (8 * sizeof(*value))) && |
| 147 | (out >= (1ull << e->length))) |
| 148 | return CMOS_OP_VALUE_TOO_WIDE; |
| 149 | |
| 150 | *value = out; |
| 151 | return OK; |
| 152 | } |
| 153 | |
| 154 | /**************************************************************************** |
| 155 | * cmos_checksum_read |
| 156 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 157 | * Read the checksum for the coreboot parameters stored in CMOS and return |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 158 | * this value. |
| 159 | ****************************************************************************/ |
| 160 | uint16_t cmos_checksum_read (void) |
| 161 | { uint16_t lo, hi; |
| 162 | |
| 163 | /* The checksum is stored in a big-endian format. */ |
| 164 | hi = cmos_read_byte(cmos_checksum_index); |
| 165 | lo = cmos_read_byte(cmos_checksum_index + 1); |
| 166 | return (hi << 8) + lo; |
| 167 | } |
| 168 | |
| 169 | /**************************************************************************** |
| 170 | * cmos_checksum_write |
| 171 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 172 | * Set the checksum for the coreboot parameters stored in CMOS to |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 173 | * 'checksum'. |
| 174 | ****************************************************************************/ |
| 175 | void cmos_checksum_write (uint16_t checksum) |
| 176 | { unsigned char lo, hi; |
| 177 | |
| 178 | /* The checksum is stored in a big-endian format. */ |
| 179 | hi = (unsigned char) (checksum >> 8); |
| 180 | lo = (unsigned char) (checksum & 0x00ff); |
| 181 | cmos_write_byte(cmos_checksum_index, hi); |
| 182 | cmos_write_byte(cmos_checksum_index + 1, lo); |
| 183 | } |
| 184 | |
| 185 | /**************************************************************************** |
| 186 | * cmos_checksum_compute |
| 187 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 188 | * Compute a checksum for the coreboot parameter values currently stored in |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 189 | * CMOS and return this checksum. |
| 190 | ****************************************************************************/ |
| 191 | uint16_t cmos_checksum_compute (void) |
| 192 | { unsigned i, sum; |
| 193 | |
| 194 | sum = 0; |
| 195 | |
| 196 | for (i = cmos_checksum_start; i <= cmos_checksum_end; i++) |
| 197 | sum += cmos_read_byte(i); |
| 198 | |
| 199 | return ~((uint16_t) (sum & 0xffff)); |
| 200 | } |
| 201 | |
| 202 | /**************************************************************************** |
| 203 | * cmos_checksum_verify |
| 204 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 205 | * Verify that the coreboot CMOS checksum is valid. If checksum is not |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 206 | * valid then print warning message and exit. |
| 207 | ****************************************************************************/ |
| 208 | void cmos_checksum_verify (void) |
| 209 | { uint16_t computed, actual; |
| 210 | |
| 211 | set_iopl(3); |
| 212 | computed = cmos_checksum_compute(); |
| 213 | actual = cmos_checksum_read(); |
| 214 | set_iopl(0); |
| 215 | |
| 216 | if (computed != actual) |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 217 | { fprintf(stderr, "%s: Warning: Coreboot CMOS checksum is bad.\n", |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 218 | prog_name); |
| 219 | exit(1); |
| 220 | } |
| 221 | } |