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   ****************************************************************************/
 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   ****************************************************************************/
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   ****************************************************************************/
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   ****************************************************************************/
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  }