Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 1 | /*****************************************************************************\ |
| 2 | * cmos_lowlevel.c |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 3 | ***************************************************************************** |
| 4 | * Copyright (C) 2002-2005 The Regents of the University of California. |
| 5 | * Produced at the Lawrence Livermore National Laboratory. |
| 6 | * Written by David S. Peterson <dsp@llnl.gov> <dave_peterson@pobox.com>. |
| 7 | * UCRL-CODE-2003-012 |
| 8 | * All rights reserved. |
| 9 | * |
Uwe Hermann | 6e56594 | 2008-03-01 19:06:32 +0000 | [diff] [blame] | 10 | * This file is part of nvramtool, a utility for reading/writing coreboot |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 11 | * parameters and displaying information from the coreboot table. |
Uwe Hermann | 6e56594 | 2008-03-01 19:06:32 +0000 | [diff] [blame] | 12 | * For details, see http://coreboot.org/nvramtool. |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 13 | * |
| 14 | * Please also read the file DISCLAIMER which is included in this software |
| 15 | * distribution. |
| 16 | * |
| 17 | * This program is free software; you can redistribute it and/or modify it |
| 18 | * under the terms of the GNU General Public License (as published by the |
| 19 | * Free Software Foundation) version 2, dated June 1991. |
| 20 | * |
| 21 | * This program is distributed in the hope that it will be useful, but |
| 22 | * WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF |
| 23 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and |
| 24 | * conditions of the GNU General Public License for more details. |
| 25 | * |
| 26 | * You should have received a copy of the GNU General Public License along |
| 27 | * with this program; if not, write to the Free Software Foundation, Inc., |
Stefan Reinauer | ac7a2d2 | 2009-09-23 21:53:25 +0000 | [diff] [blame^] | 28 | * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 29 | \*****************************************************************************/ |
| 30 | |
Andriy Gapon | 6a4bf98 | 2008-10-30 15:41:39 +0000 | [diff] [blame] | 31 | #if defined(__FreeBSD__) |
| 32 | #include <fcntl.h> |
| 33 | #include <unistd.h> |
| 34 | #endif |
| 35 | |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 36 | #include "common.h" |
| 37 | #include "cmos_lowlevel.h" |
| 38 | |
| 39 | typedef struct |
| 40 | { unsigned byte_index; |
| 41 | unsigned bit_offset; |
| 42 | } |
| 43 | cmos_bit_op_location_t; |
| 44 | |
| 45 | static unsigned cmos_bit_op_strategy (unsigned bit, unsigned bits_left, |
| 46 | cmos_bit_op_location_t *where); |
| 47 | static unsigned char cmos_read_bits (const cmos_bit_op_location_t *where, |
| 48 | unsigned nr_bits); |
| 49 | static void cmos_write_bits (const cmos_bit_op_location_t *where, |
| 50 | unsigned nr_bits, unsigned char value); |
| 51 | static unsigned char get_bits (unsigned long long value, unsigned bit, |
| 52 | unsigned nr_bits); |
| 53 | static void put_bits (unsigned char value, unsigned bit, unsigned nr_bits, |
| 54 | unsigned long long *result); |
| 55 | |
| 56 | /**************************************************************************** |
| 57 | * get_bits |
| 58 | * |
| 59 | * Extract a value 'nr_bits' bits wide starting at bit position 'bit' from |
| 60 | * 'value' and return the result. It is assumed that 'nr_bits' is at most 8. |
| 61 | ****************************************************************************/ |
| 62 | static inline unsigned char get_bits (unsigned long long value, unsigned bit, |
| 63 | unsigned nr_bits) |
| 64 | { return (value >> bit) & ((unsigned char) ((1 << nr_bits) - 1)); } |
| 65 | |
| 66 | /**************************************************************************** |
| 67 | * put_bits |
| 68 | * |
| 69 | * Extract the low order 'nr_bits' bits from 'value' and store them in the |
| 70 | * value pointed to by 'result' starting at bit position 'bit'. The bit |
| 71 | * positions in 'result' where the result is stored are assumed to be |
| 72 | * initially zero. |
| 73 | ****************************************************************************/ |
| 74 | static inline void put_bits (unsigned char value, unsigned bit, |
| 75 | unsigned nr_bits, unsigned long long *result) |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 76 | { *result += ((unsigned long long)(value & ((unsigned char) ((1 << nr_bits) - 1)))) << bit; } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 77 | |
| 78 | /**************************************************************************** |
| 79 | * cmos_read |
| 80 | * |
| 81 | * Read value from nonvolatile RAM at position given by 'bit' and 'length' |
| 82 | * and return this value. The I/O privilege level of the currently executing |
| 83 | * process must be set appropriately. |
| 84 | ****************************************************************************/ |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 85 | unsigned long long cmos_read (const cmos_entry_t *e) |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 86 | { cmos_bit_op_location_t where; |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 87 | unsigned bit = e->bit, length=e->length; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 88 | unsigned next_bit, bits_left, nr_bits; |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 89 | unsigned long long result = 0; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 90 | unsigned char value; |
| 91 | |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 92 | assert(!verify_cmos_op(bit, length, e->config)); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 93 | result = 0; |
| 94 | |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 95 | if (e->config == CMOS_ENTRY_STRING) |
| 96 | { char *newstring = malloc((length+7)/8); |
| 97 | unsigned usize = (8 * sizeof(unsigned long long)); |
| 98 | |
| 99 | if(!newstring) { out_of_memory(); } |
| 100 | |
| 101 | for (next_bit = 0, bits_left = length; |
| 102 | bits_left; |
| 103 | next_bit += nr_bits, bits_left -= nr_bits) |
| 104 | { nr_bits = cmos_bit_op_strategy(bit + next_bit, bits_left>usize?usize:bits_left, &where); |
| 105 | value = cmos_read_bits(&where, nr_bits); |
| 106 | put_bits(value, next_bit % usize, nr_bits, &((unsigned long long *)newstring)[next_bit/usize]); |
| 107 | result = (unsigned long)newstring; |
| 108 | } |
| 109 | } |
| 110 | else |
| 111 | { for (next_bit = 0, bits_left = length; |
| 112 | bits_left; |
| 113 | next_bit += nr_bits, bits_left -= nr_bits) |
| 114 | { nr_bits = cmos_bit_op_strategy(bit + next_bit, bits_left, &where); |
| 115 | value = cmos_read_bits(&where, nr_bits); |
| 116 | put_bits(value, next_bit, nr_bits, &result); |
| 117 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | return result; |
| 121 | } |
| 122 | |
| 123 | /**************************************************************************** |
| 124 | * cmos_write |
| 125 | * |
| 126 | * Write 'data' to nonvolatile RAM at position given by 'bit' and 'length'. |
| 127 | * The I/O privilege level of the currently executing process must be set |
| 128 | * appropriately. |
| 129 | ****************************************************************************/ |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 130 | void cmos_write (const cmos_entry_t *e, unsigned long long value) |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 131 | { cmos_bit_op_location_t where; |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 132 | unsigned bit = e->bit, length=e->length; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 133 | unsigned next_bit, bits_left, nr_bits; |
| 134 | |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 135 | assert(!verify_cmos_op(bit, length, e->config)); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 136 | |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 137 | if (e->config == CMOS_ENTRY_STRING) |
| 138 | { unsigned long long *data = (unsigned long long *)(unsigned long)value; |
| 139 | unsigned usize = (8 * sizeof(unsigned long long)); |
| 140 | |
| 141 | for (next_bit = 0, bits_left = length; |
| 142 | bits_left; |
| 143 | next_bit += nr_bits, bits_left -= nr_bits) |
| 144 | { nr_bits = cmos_bit_op_strategy(bit + next_bit, bits_left>usize?usize:bits_left, &where); |
| 145 | value = data[next_bit/usize]; |
| 146 | cmos_write_bits(&where, nr_bits, get_bits(value, next_bit % usize, nr_bits)); |
| 147 | } |
| 148 | } |
| 149 | else |
| 150 | { for (next_bit = 0, bits_left = length; |
| 151 | bits_left; |
| 152 | next_bit += nr_bits, bits_left -= nr_bits) |
| 153 | { nr_bits = cmos_bit_op_strategy(bit + next_bit, bits_left, &where); |
| 154 | cmos_write_bits(&where, nr_bits, get_bits(value, next_bit, nr_bits)); |
| 155 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 156 | } |
| 157 | } |
| 158 | |
| 159 | /**************************************************************************** |
| 160 | * cmos_read_byte |
| 161 | * |
| 162 | * Read a byte from nonvolatile RAM at a position given by 'index' and return |
| 163 | * the result. An 'index' value of 0 represents the first byte of |
| 164 | * nonvolatile RAM. |
| 165 | * |
| 166 | * Note: the first 14 bytes of nonvolatile RAM provide an interface to the |
| 167 | * real time clock. |
| 168 | ****************************************************************************/ |
| 169 | unsigned char cmos_read_byte (unsigned index) |
| 170 | { unsigned short port_0, port_1; |
| 171 | |
| 172 | assert(!verify_cmos_byte_index(index)); |
| 173 | |
| 174 | if (index < 128) |
| 175 | { port_0 = 0x70; |
| 176 | port_1 = 0x71; |
| 177 | } |
| 178 | else |
| 179 | { port_0 = 0x72; |
| 180 | port_1 = 0x73; |
| 181 | } |
| 182 | |
Andriy Gapon | 6a4bf98 | 2008-10-30 15:41:39 +0000 | [diff] [blame] | 183 | OUTB(index, port_0); |
| 184 | return INB(port_1); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 185 | } |
| 186 | |
| 187 | /**************************************************************************** |
| 188 | * cmos_write_byte |
| 189 | * |
| 190 | * Write 'value' to nonvolatile RAM at a position given by 'index'. An |
| 191 | * 'index' of 0 represents the first byte of nonvolatile RAM. |
| 192 | * |
| 193 | * Note: the first 14 bytes of nonvolatile RAM provide an interface to the |
| 194 | * real time clock. Writing to any of these bytes will therefore |
| 195 | * affect its functioning. |
| 196 | ****************************************************************************/ |
| 197 | void cmos_write_byte (unsigned index, unsigned char value) |
| 198 | { unsigned short port_0, port_1; |
| 199 | |
| 200 | assert(!verify_cmos_byte_index(index)); |
| 201 | |
| 202 | if (index < 128) |
| 203 | { port_0 = 0x70; |
| 204 | port_1 = 0x71; |
| 205 | } |
| 206 | else |
| 207 | { port_0 = 0x72; |
| 208 | port_1 = 0x73; |
| 209 | } |
| 210 | |
Andriy Gapon | 6a4bf98 | 2008-10-30 15:41:39 +0000 | [diff] [blame] | 211 | OUTB(index, port_0); |
| 212 | OUTB(value, port_1); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 213 | } |
| 214 | |
| 215 | /**************************************************************************** |
| 216 | * cmos_read_all |
| 217 | * |
| 218 | * Read all contents of CMOS memory into array 'data'. The first 14 bytes of |
| 219 | * 'data' are set to zero since this corresponds to the real time clock area. |
| 220 | ****************************************************************************/ |
| 221 | void cmos_read_all (unsigned char data[]) |
| 222 | { unsigned i; |
| 223 | |
| 224 | for (i = 0; i < CMOS_RTC_AREA_SIZE; i++) |
| 225 | data[i] = 0; |
| 226 | |
| 227 | for (; i < CMOS_SIZE; i++) |
| 228 | data[i] = cmos_read_byte(i); |
| 229 | } |
| 230 | |
| 231 | /**************************************************************************** |
| 232 | * cmos_write_all |
| 233 | * |
| 234 | * Update all of CMOS memory with the contents of array 'data'. The first 14 |
| 235 | * bytes of 'data' are ignored since this corresponds to the real time clock |
| 236 | * area. |
| 237 | ****************************************************************************/ |
| 238 | void cmos_write_all (unsigned char data[]) |
| 239 | { unsigned i; |
| 240 | |
| 241 | for (i = CMOS_RTC_AREA_SIZE; i < CMOS_SIZE; i++) |
| 242 | cmos_write_byte(i, data[i]); |
| 243 | } |
| 244 | |
| 245 | /**************************************************************************** |
| 246 | * set_iopl |
| 247 | * |
| 248 | * Set the I/O privilege level of the executing process. Root privileges are |
| 249 | * required for performing this action. A sufficient I/O privilege level |
| 250 | * allows the process to access x86 I/O address space and to disable/reenable |
| 251 | * interrupts while executing in user space. Messing with the I/O privilege |
| 252 | * level is therefore somewhat dangerous. |
| 253 | ****************************************************************************/ |
| 254 | void set_iopl (int level) |
Andriy Gapon | 6a4bf98 | 2008-10-30 15:41:39 +0000 | [diff] [blame] | 255 | { |
| 256 | #if defined(__FreeBSD__) |
| 257 | static int io_fd = -1; |
| 258 | #endif |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 259 | |
Andriy Gapon | 6a4bf98 | 2008-10-30 15:41:39 +0000 | [diff] [blame] | 260 | assert((level >= 0) && (level <= 3)); |
| 261 | |
| 262 | #if defined(__FreeBSD__) |
| 263 | if (level == 0) |
| 264 | { |
| 265 | if (io_fd != -1) |
| 266 | { |
| 267 | close(io_fd); |
| 268 | io_fd = -1; |
| 269 | } |
| 270 | } |
| 271 | else |
| 272 | { |
| 273 | if (io_fd == -1) |
| 274 | { |
| 275 | io_fd = open("/dev/io", O_RDWR); |
| 276 | if (io_fd < 0) |
| 277 | { |
| 278 | perror("/dev/io"); |
| 279 | exit(1); |
| 280 | } |
| 281 | } |
| 282 | } |
| 283 | #else |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 284 | if (iopl(level)) |
| 285 | { fprintf(stderr, |
| 286 | "%s: iopl() system call failed. You must be root to do " |
| 287 | "this.\n", |
| 288 | prog_name); |
| 289 | exit(1); |
| 290 | } |
Andriy Gapon | 6a4bf98 | 2008-10-30 15:41:39 +0000 | [diff] [blame] | 291 | #endif |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 292 | } |
| 293 | |
| 294 | /**************************************************************************** |
| 295 | * verify_cmos_op |
| 296 | * |
| 297 | * 'bit' represents a bit position in the nonvolatile RAM. The first bit |
| 298 | * (i.e. the lowest order bit of the first byte) of nonvolatile RAM is |
| 299 | * labeled as bit 0. 'length' represents the width in bits of a value we |
| 300 | * wish to read or write. Perform sanity checking on 'bit' and 'length'. If |
| 301 | * no problems were encountered, return OK. Else return an error code. |
| 302 | ****************************************************************************/ |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 303 | int verify_cmos_op (unsigned bit, unsigned length, cmos_entry_config_t config) |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 304 | { if ((bit >= (8 * CMOS_SIZE)) || ((bit + length) > (8 * CMOS_SIZE))) |
| 305 | return CMOS_AREA_OUT_OF_RANGE; |
| 306 | |
| 307 | if (bit < (8 * CMOS_RTC_AREA_SIZE)) |
| 308 | return CMOS_AREA_OVERLAPS_RTC; |
| 309 | |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 310 | if (config == CMOS_ENTRY_STRING) |
| 311 | return OK; |
| 312 | |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 313 | if (length > (8 * sizeof(unsigned long long))) |
| 314 | return CMOS_AREA_TOO_WIDE; |
| 315 | |
| 316 | return OK; |
| 317 | } |
| 318 | |
| 319 | /**************************************************************************** |
| 320 | * cmos_bit_op_strategy |
| 321 | * |
| 322 | * Helper function used by cmos_read() and cmos_write() to determine which |
| 323 | * bits to read or write next. |
| 324 | ****************************************************************************/ |
| 325 | static unsigned cmos_bit_op_strategy (unsigned bit, unsigned bits_left, |
| 326 | cmos_bit_op_location_t *where) |
| 327 | { unsigned max_bits; |
| 328 | |
| 329 | where->byte_index = bit >> 3; |
| 330 | where->bit_offset = bit & 0x07; |
| 331 | max_bits = 8 - where->bit_offset; |
| 332 | return (bits_left > max_bits) ? max_bits : bits_left; |
| 333 | } |
| 334 | |
| 335 | /**************************************************************************** |
| 336 | * cmos_read_bits |
| 337 | * |
| 338 | * Read a chunk of bits from a byte location within CMOS memory. Return the |
| 339 | * value represented by the chunk of bits. |
| 340 | ****************************************************************************/ |
| 341 | static unsigned char cmos_read_bits (const cmos_bit_op_location_t *where, |
| 342 | unsigned nr_bits) |
| 343 | { return (cmos_read_byte(where->byte_index) >> where->bit_offset) & |
| 344 | ((unsigned char) ((1 << nr_bits) - 1)); |
| 345 | } |
| 346 | |
| 347 | /**************************************************************************** |
| 348 | * cmos_write_bits |
| 349 | * |
| 350 | * Write a chunk of bits (the low order 'nr_bits' bits of 'value') to an area |
| 351 | * within a particular byte of CMOS memory. |
| 352 | ****************************************************************************/ |
| 353 | static void cmos_write_bits (const cmos_bit_op_location_t *where, |
| 354 | unsigned nr_bits, unsigned char value) |
| 355 | { unsigned char n, mask; |
| 356 | |
| 357 | if (nr_bits == 8) |
| 358 | { cmos_write_byte(where->byte_index, value); |
| 359 | return; |
| 360 | } |
| 361 | |
| 362 | n = cmos_read_byte(where->byte_index); |
| 363 | mask = ((unsigned char) ((1 << nr_bits) - 1)) << where->bit_offset; |
| 364 | n = (n & ~mask) + ((value << where->bit_offset) & mask); |
| 365 | cmos_write_byte(where->byte_index, n); |
| 366 | } |