Patrick Georgi | 55189c9 | 2020-05-10 20:09:31 +0200 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 2 | |
| 3 | #include "common.h" |
| 4 | #include "cmos_ops.h" |
| 5 | #include "cmos_lowlevel.h" |
| 6 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 7 | static int prepare_cmos_op_common(const cmos_entry_t * e); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 8 | |
| 9 | /**************************************************************************** |
| 10 | * prepare_cmos_op_common |
| 11 | * |
| 12 | * Perform a few checks common to both reads and writes. |
| 13 | ****************************************************************************/ |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 14 | static int prepare_cmos_op_common(const cmos_entry_t * e) |
| 15 | { |
| 16 | int result; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 17 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 18 | if (e->config == CMOS_ENTRY_RESERVED) |
| 19 | /* Access to reserved parameters is not permitted. */ |
| 20 | return CMOS_OP_RESERVED; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 21 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 22 | if ((result = verify_cmos_op(e->bit, e->length, e->config)) != OK) |
| 23 | return result; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 24 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 25 | assert(e->length > 0); |
| 26 | return OK; |
| 27 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 28 | |
| 29 | /**************************************************************************** |
| 30 | * prepare_cmos_read |
| 31 | * |
| 32 | * The caller wishes to read a CMOS parameter represented by 'e'. Perform |
| 33 | * sanity checking on 'e'. If a problem was found with e, return an error |
| 34 | * code. Else return OK. |
| 35 | ****************************************************************************/ |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 36 | int prepare_cmos_read(const cmos_entry_t * e) |
| 37 | { |
| 38 | int result; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 39 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 40 | if ((result = prepare_cmos_op_common(e)) != OK) |
| 41 | return result; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 42 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 43 | switch (e->config) { |
| 44 | case CMOS_ENTRY_ENUM: |
| 45 | case CMOS_ENTRY_HEX: |
| 46 | case CMOS_ENTRY_STRING: |
| 47 | break; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 48 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 49 | default: |
| 50 | BUG(); |
| 51 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 52 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 53 | return OK; |
| 54 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 55 | |
| 56 | /**************************************************************************** |
| 57 | * prepare_cmos_write |
| 58 | * |
| 59 | * The caller wishes to set a CMOS parameter represented by 'e' to a value |
| 60 | * whose string representation is stored in 'value_str'. Perform sanity |
| 61 | * checking on 'value_str'. On error, return an error code. Else store the |
| 62 | * numeric equivalent of 'value_str' in '*value' and return OK. |
| 63 | ****************************************************************************/ |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 64 | int prepare_cmos_write(const cmos_entry_t * e, const char value_str[], |
| 65 | unsigned long long *value) |
| 66 | { |
| 67 | const cmos_enum_t *q; |
| 68 | unsigned long long out; |
| 69 | const char *p; |
Patrick Georgi | dd1aab9 | 2014-08-09 17:06:20 +0200 | [diff] [blame] | 70 | char *memory = NULL; |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 71 | int negative, result, found_one; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 72 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 73 | if ((result = prepare_cmos_op_common(e)) != OK) |
| 74 | return result; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 75 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 76 | switch (e->config) { |
| 77 | case CMOS_ENTRY_ENUM: |
| 78 | /* Make sure the user's input corresponds to a valid option. */ |
| 79 | for (q = first_cmos_enum_id(e->config_id), found_one = 0; |
| 80 | q != NULL; q = next_cmos_enum_id(q)) { |
| 81 | found_one = 1; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 82 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 83 | if (!strncmp(q->text, value_str, CMOS_MAX_TEXT_LENGTH)) |
| 84 | break; |
| 85 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 86 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 87 | if (!found_one) |
| 88 | return CMOS_OP_NO_MATCHING_ENUM; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 89 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 90 | if (q == NULL) |
| 91 | return CMOS_OP_BAD_ENUM_VALUE; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 92 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 93 | out = q->value; |
| 94 | break; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 95 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 96 | case CMOS_ENTRY_HEX: |
Stefan Reinauer | 14e2277 | 2010-04-27 06:56:47 +0000 | [diff] [blame] | 97 | /* See if the first character of 'value_str' (excluding |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 98 | * any initial whitespace) is a minus sign. |
| 99 | */ |
Jonathan Kollasch | 1571dc9 | 2011-04-19 19:34:25 +0000 | [diff] [blame] | 100 | for (p = value_str; isspace((int)(unsigned char)*p); p++) ; |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 101 | negative = (*p == '-'); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 102 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 103 | out = strtoull(value_str, (char **)&p, 0); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 104 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 105 | if (*p) |
| 106 | return CMOS_OP_INVALID_INT; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 107 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 108 | /* If we get this far, the user specified a valid integer. |
| 109 | * However we do not currently support the use of negative |
| 110 | * numbers as CMOS parameter values. |
| 111 | */ |
| 112 | if (negative) |
| 113 | return CMOS_OP_NEGATIVE_INT; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 114 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 115 | break; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 116 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 117 | case CMOS_ENTRY_STRING: |
| 118 | if (e->length < (8 * strlen(value_str))) |
| 119 | return CMOS_OP_VALUE_TOO_WIDE; |
| 120 | memory = malloc(e->length / 8); |
| 121 | memset(memory, 0, e->length / 8); |
| 122 | strcpy(memory, value_str); |
| 123 | out = (unsigned long)memory; |
| 124 | break; |
Stefan Reinauer | a67aab7 | 2008-09-27 10:08:28 +0000 | [diff] [blame] | 125 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 126 | default: |
| 127 | BUG(); |
| 128 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 129 | |
Patrick Georgi | dd1aab9 | 2014-08-09 17:06:20 +0200 | [diff] [blame] | 130 | if ((e->length < (8 * sizeof(*value))) && (out >= (1ull << e->length))) { |
| 131 | if (memory) free(memory); |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 132 | return CMOS_OP_VALUE_TOO_WIDE; |
Patrick Georgi | dd1aab9 | 2014-08-09 17:06:20 +0200 | [diff] [blame] | 133 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 134 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 135 | *value = out; |
| 136 | return OK; |
| 137 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 138 | |
| 139 | /**************************************************************************** |
| 140 | * cmos_checksum_read |
| 141 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 142 | * Read the checksum for the coreboot parameters stored in CMOS and return |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 143 | * this value. |
| 144 | ****************************************************************************/ |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 145 | uint16_t cmos_checksum_read(void) |
| 146 | { |
| 147 | uint16_t lo, hi; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 148 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 149 | /* The checksum is stored in a big-endian format. */ |
| 150 | hi = cmos_read_byte(cmos_checksum_index); |
| 151 | lo = cmos_read_byte(cmos_checksum_index + 1); |
| 152 | return (hi << 8) + lo; |
| 153 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 154 | |
| 155 | /**************************************************************************** |
| 156 | * cmos_checksum_write |
| 157 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 158 | * Set the checksum for the coreboot parameters stored in CMOS to |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 159 | * 'checksum'. |
| 160 | ****************************************************************************/ |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 161 | void cmos_checksum_write(uint16_t checksum) |
| 162 | { |
| 163 | unsigned char lo, hi; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 164 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 165 | /* The checksum is stored in a big-endian format. */ |
| 166 | hi = (unsigned char)(checksum >> 8); |
| 167 | lo = (unsigned char)(checksum & 0x00ff); |
| 168 | cmos_write_byte(cmos_checksum_index, hi); |
| 169 | cmos_write_byte(cmos_checksum_index + 1, lo); |
| 170 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 171 | |
| 172 | /**************************************************************************** |
| 173 | * cmos_checksum_compute |
| 174 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 175 | * Compute a checksum for the coreboot parameter values currently stored in |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 176 | * CMOS and return this checksum. |
| 177 | ****************************************************************************/ |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 178 | uint16_t cmos_checksum_compute(void) |
| 179 | { |
| 180 | unsigned i, sum; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 181 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 182 | sum = 0; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 183 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 184 | for (i = cmos_checksum_start; i <= cmos_checksum_end; i++) |
| 185 | sum += cmos_read_byte(i); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 186 | |
Stefan Reinauer | c31c4de | 2011-10-17 08:58:27 -0700 | [diff] [blame] | 187 | return (uint16_t)(sum & 0xffff); |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 188 | } |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 189 | |
| 190 | /**************************************************************************** |
| 191 | * cmos_checksum_verify |
| 192 | * |
Stefan Reinauer | f527e70 | 2008-01-18 15:33:49 +0000 | [diff] [blame] | 193 | * Verify that the coreboot CMOS checksum is valid. If checksum is not |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 194 | * valid then print warning message and exit. |
| 195 | ****************************************************************************/ |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 196 | void cmos_checksum_verify(void) |
| 197 | { |
| 198 | uint16_t computed, actual; |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 199 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 200 | set_iopl(3); |
| 201 | computed = cmos_checksum_compute(); |
| 202 | actual = cmos_checksum_read(); |
| 203 | set_iopl(0); |
Stefan Reinauer | 6540ae5 | 2007-07-12 16:35:42 +0000 | [diff] [blame] | 204 | |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 205 | if (computed != actual) { |
Martin Roth | a564811 | 2017-06-03 20:05:42 -0600 | [diff] [blame] | 206 | fprintf(stderr, "%s: Warning: coreboot CMOS checksum is bad.\n", |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 207 | prog_name); |
Denis 'GNUtoo' Carikli | 9c44b25 | 2016-02-20 18:49:13 +0100 | [diff] [blame] | 208 | fprintf(stderr, "Computed checksum: 0x%x. Stored checksum: 0x%x\n", |
| 209 | computed, actual); |
Stefan Reinauer | 90b96b6 | 2010-01-13 21:00:23 +0000 | [diff] [blame] | 210 | exit(1); |
| 211 | } |
| 212 | } |