1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #include "common.h"
4 #include "input_file.h"
5 #include "layout.h"
6 #include "cmos_ops.h"
7 #include "cmos_lowlevel.h"
8 #include "reg_expr.h"
9
10 static int get_input_file_line(FILE * f, char line[], int line_buf_size);
11 static unsigned long long try_prepare_cmos_write(const cmos_entry_t * e,
12 const char value_str[]);
13
14 /* matches either a blank line or a comment line */
15 static const char blank_or_comment_regex[] =
16 /* a blank line */
17 "(^[[:space:]]+$)" "|" /* or ... */
18 /* a line consisting of: optional whitespace followed by */
19 "(^[[:space:]]*"
20 /* a '#' character and optionally, additional characters */
21 "#.*$)";
22
23 /* matches an assignment line */
24 const char assignment_regex[] =
25 /* optional whitespace */
26 "^[[:space:]]*"
27 /* followed by a coreboot parameter name */
28 "([^[:space:]]+)"
29 /* followed by optional whitespace */
30 "[[:space:]]*"
31 /* followed by an '=' character */
32 "="
33 /* followed by optional whitespace */
34 "[[:space:]]*"
35 /* followed by a value that may contain embedded whitespace */
36 "([^[:space:]]+([[:space:]]+[^[:space:]]+)*)+"
37 /* followed by optional whitespace */
38 "[[:space:]]*$";
39
40 static int line_num;
41
42 /****************************************************************************
43 * process_input_file
44 *
45 * Read the contents of file 'f' and return a pointer to a list of pending
46 * write operations. Perform sanity checking on all write operations and
47 * exit with an error message if there is a problem.
48 ****************************************************************************/
process_input_file(FILE * f)49 cmos_write_t *process_input_file(FILE * f)
50 {
51 static const int LINE_BUF_SIZE = 256;
52 static const size_t N_MATCHES = 4;
53 char line[LINE_BUF_SIZE];
54 const char *name, *value;
55 cmos_write_t *list, *item, **p;
56 regex_t blank_or_comment, assignment;
57 regmatch_t match[N_MATCHES];
58 const cmos_entry_t *e;
59
60 list = NULL;
61 p = &list;
62
63 compile_reg_expr(REG_EXTENDED | REG_NEWLINE, blank_or_comment_regex, &blank_or_comment);
64 compile_reg_expr(REG_EXTENDED | REG_NEWLINE, assignment_regex, &assignment);
65
66 /* each iteration processes one line from input file */
67 for (line_num = 1; get_input_file_line(f, line, LINE_BUF_SIZE) == OK; line_num++) { /* skip comments and blank lines */
68 if (!regexec(&blank_or_comment, line, 0, NULL, 0))
69 continue;
70
71 /* Is this a valid assignment line? If not, then it's a syntax
72 * error.
73 */
74 if (regexec(&assignment, line, N_MATCHES, match, 0)) {
75 fprintf(stderr,
76 "%s: Syntax error on line %d of input file.\n",
77 prog_name, line_num);
78 exit(1);
79 }
80
81 /* OK, we found an assignment. Break the line into substrings
82 * representing the lefthand and righthand sides of the assignment.
83 */
84 line[match[1].rm_eo] = '\0';
85 line[match[2].rm_eo] = '\0';
86 name = &line[match[1].rm_so];
87 value = &line[match[2].rm_so];
88
89 /* now look up the coreboot parameter name */
90 if (is_checksum_name(name)
91 || (e = find_cmos_entry(name)) == NULL) {
92 fprintf(stderr,
93 "%s: Error on line %d of input file: CMOS parameter "
94 "%s not found.\n", prog_name, line_num, name);
95 exit(1);
96 }
97
98 /* At this point, we figure out what numeric value needs to be written
99 * to which location. At the same time, we perform sanity checking on
100 * the write operation.
101 */
102
103 if ((item = (cmos_write_t *) malloc(sizeof(*item))) == NULL)
104 out_of_memory();
105
106 item->bit = e->bit;
107 item->length = e->length;
108 item->config = e->config;
109 item->value = try_prepare_cmos_write(e, value);
110
111 /* Append write operation to pending write list. */
112 item->next = NULL;
113 *p = item;
114 p = &item->next;
115 }
116
117 regfree(&blank_or_comment);
118 regfree(&assignment);
119 return list;
120 }
121
122 /****************************************************************************
123 * do_cmos_writes
124 *
125 * 'list' is a linked list of pending CMOS write operations that have passed
126 * all sanity checks. Perform all write operations, destroying the list as
127 * we go.
128 ****************************************************************************/
do_cmos_writes(cmos_write_t * list)129 void do_cmos_writes(cmos_write_t * list)
130 {
131 cmos_write_t *item;
132
133 set_iopl(3);
134
135 while (list != NULL) {
136 cmos_entry_t e;
137 item = list;
138 e.bit = item->bit;
139 e.length = item->length;
140 e.config = item->config;
141 list = item->next;
142 cmos_write(&e, item->value);
143 free(item);
144 }
145
146 cmos_checksum_write(cmos_checksum_compute());
147 set_iopl(0);
148 }
149
150 /****************************************************************************
151 * get_input_file_line
152 *
153 * Get a line of input from file 'f'. Store result in 'line' which is an
154 * array of 'line_buf_size' bytes. Return OK on success or an error code on
155 * error.
156 ****************************************************************************/
get_input_file_line(FILE * f,char line[],int line_buf_size)157 static int get_input_file_line(FILE * f, char line[], int line_buf_size)
158 {
159 switch (get_line_from_file(f, line, line_buf_size)) {
160 case OK:
161 return OK;
162
163 case LINE_EOF:
164 return LINE_EOF;
165
166 case LINE_TOO_LONG:
167 fprintf(stderr,
168 "%s: Error on line %d of input file: Maximum line "
169 "length exceeded. Max is %d characters.\n", prog_name,
170 line_num, line_buf_size - 2);
171 break;
172
173 default:
174 BUG();
175 }
176
177 exit(1);
178 return 1; /* keep compiler happy */
179 }
180
181 /****************************************************************************
182 * try_prepare_cmos_write
183 *
184 * Attempt to convert 'value_str' to an integer representation for storage in
185 * CMOS memory. On success, return the converted value. On error, exit with
186 * an error message.
187 ****************************************************************************/
try_prepare_cmos_write(const cmos_entry_t * e,const char value_str[])188 static unsigned long long try_prepare_cmos_write(const cmos_entry_t * e,
189 const char value_str[])
190 {
191 unsigned long long value;
192
193 switch (prepare_cmos_write(e, value_str, &value)) {
194 case OK:
195 return value;
196
197 case CMOS_OP_BAD_ENUM_VALUE:
198 fprintf(stderr,
199 "%s: Error on line %d of input file: Bad value for "
200 "parameter %s.", prog_name, line_num, e->name);
201 break;
202
203 case CMOS_OP_NEGATIVE_INT:
204 fprintf(stderr,
205 "%s: Error on line %d of input file: This program "
206 "does not support assignment of negative numbers to "
207 "coreboot parameters.", prog_name, line_num);
208 break;
209
210 case CMOS_OP_INVALID_INT:
211 fprintf(stderr,
212 "%s: Error on line %d of input file: %s is not a "
213 "valid integer.", prog_name, line_num, value_str);
214 break;
215
216 case CMOS_OP_RESERVED:
217 fprintf(stderr,
218 "%s: Error on line %d of input file: Can not modify "
219 "reserved coreboot parameter %s.", prog_name, line_num,
220 e->name);
221 break;
222
223 case CMOS_OP_VALUE_TOO_WIDE:
224 fprintf(stderr,
225 "%s: Error on line %d of input file: Can not write "
226 "value %s to CMOS parameter %s that is only %d bits wide.",
227 prog_name, line_num, value_str, e->name, e->length);
228 break;
229
230 case CMOS_OP_NO_MATCHING_ENUM:
231 fprintf(stderr,
232 "%s: coreboot parameter %s has no matching enums.",
233 prog_name, e->name);
234 break;
235
236 case CMOS_AREA_OUT_OF_RANGE:
237 fprintf(stderr,
238 "%s: The CMOS area specified by the layout info for "
239 "coreboot parameter %s is out of range.", prog_name,
240 e->name);
241 break;
242
243 case CMOS_AREA_OVERLAPS_RTC:
244 fprintf(stderr,
245 "%s: The CMOS area specified by the layout info for "
246 "coreboot parameter %s overlaps the realtime clock area.",
247 prog_name, e->name);
248 break;
249
250 case CMOS_AREA_TOO_WIDE:
251 fprintf(stderr,
252 "%s: The CMOS area specified by the layout info for "
253 "coreboot parameter %s is too wide.", prog_name,
254 e->name);
255 break;
256
257 default:
258 fprintf(stderr,
259 "%s: Unknown error encountered while attempting to modify "
260 "coreboot parameter %s.", prog_name, e->name);
261 break;
262 }
263
264 fprintf(stderr, " No CMOS writes performed.\n");
265 exit(1);
266 return 0; /* keep compiler happy */
267 }
268