util/lxbios/input_file.c

/*****************************************************************************\
 * input_file.c
 * $Id: input_file.c,v 1.3 2006/01/24 00:25:40 dsp_llnl Exp $
 *****************************************************************************
 *  Copyright (C) 2002-2005 The Regents of the University of California.
 *  Produced at the Lawrence Livermore National Laboratory.
 *  Written by David S. Peterson <dsp@llnl.gov> <dave_peterson@pobox.com>.
 *  UCRL-CODE-2003-012
 *  All rights reserved.
 *
 *  This file is part of lxbios, a utility for reading/writing coreboot
 *  parameters and displaying information from the coreboot table.
 *  For details, see <http://www.llnl.gov/linux/lxbios/>.
 *
 *  Please also read the file DISCLAIMER which is included in this software
 *  distribution.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License (as published by the
 *  Free Software Foundation) version 2, dated June 1991.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the terms and
 *  conditions of the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
\*****************************************************************************/

#include "common.h"
#include "input_file.h"
#include "layout.h"
#include "cmos_ops.h"
#include "cmos_lowlevel.h"
#include "reg_expr.h"

static int get_input_file_line (FILE *f, char line[], int line_buf_size);
static unsigned long long try_prepare_cmos_write (const cmos_entry_t *e,
                                                  const char value_str[]);

/* matches either a blank line or a comment line */
static const char blank_or_comment_regex[] =
   /* a blank line */
   "(^[[:space:]]+$)"

   "|"  /* or ... */

   /* a line consisting of: optional whitespace followed by */
   "(^[[:space:]]*"
   /* a '#' character and optionally, additional characters */
   "#.*$)";

/* matches an assignment line */
const char assignment_regex[] =
   /* optional whitespace */
   "^[[:space:]]*"
   /* followed by a coreboot parameter name */
   "([^[:space:]]+)"
   /* followed by optional whitespace */
   "[[:space:]]*"
   /* followed by an '=' character */
   "="
   /* followed by optional whitespace */
   "[[:space:]]*"
   /* followed by a value that may contain embedded whitespace */
   "([^[:space:]]+([[:space:]]+[^[:space:]]+)*)+"
   /* followed by optional whitespace */
   "[[:space:]]*$";

static int line_num;

/****************************************************************************
 * process_input_file
 *
 * Read the contents of file 'f' and return a pointer to a list of pending
 * write operations.  Perform sanity checking on all write operations and
 * exit with an error message if there is a problem.
 ****************************************************************************/
cmos_write_t * process_input_file (FILE *f)
 {
   static const int LINE_BUF_SIZE = 256;
   static const size_t N_MATCHES = 4;
   char line[LINE_BUF_SIZE];
   const char *name, *value;
   cmos_write_t *list, *item, **p;
   regex_t blank_or_comment, assignment;
   regmatch_t match[N_MATCHES];
   const cmos_entry_t *e;

   list = NULL;
   p = &list;

   compile_reg_exprs(REG_EXTENDED | REG_NEWLINE, 2, blank_or_comment_regex,
                     &blank_or_comment, assignment_regex, &assignment);

   /* each iteration processes one line from input file */
   for (line_num = 1;
        get_input_file_line(f, line, LINE_BUF_SIZE) == OK;
        line_num++)
    { /* skip comments and blank lines */
      if (!regexec(&blank_or_comment, line, 0, NULL, 0))
         continue;

      /* Is this a valid assignment line?  If not, then it's a syntax
       * error.
       */
      if (regexec(&assignment, line, N_MATCHES, match, 0))
       { fprintf(stderr, "%s: Syntax error on line %d of input file.\n",
                 prog_name, line_num);
         exit(1);
       }

      /* OK, we found an assignment.  Break the line into substrings
       * representing the lefthand and righthand sides of the assignment.
       */
      line[match[1].rm_eo] = '\0';
      line[match[2].rm_eo] = '\0';
      name = &line[match[1].rm_so];
      value = &line[match[2].rm_so];

      /* now look up the coreboot parameter name */
      if (is_checksum_name(name) || (e = find_cmos_entry(name)) == NULL)
       { fprintf(stderr, "%s: Error on line %d of input file: CMOS parameter "
                 "%s not found.\n", prog_name, line_num, name);
         exit(1);
       }

      /* At this point, we figure out what numeric value needs to be written
       * to which location.  At the same time, we perform sanity checking on
       * the write operation.
       */

      if ((item = (cmos_write_t *) malloc(sizeof(*item))) == NULL)
         out_of_memory();

      item->bit = e->bit;
      item->length = e->length;
      item->value = try_prepare_cmos_write(e, value);

      /* Append write operation to pending write list. */
      item->next = NULL;
      *p = item;
      p = &item->next;
    }

   free_reg_exprs(2, &blank_or_comment, &assignment);
   return list;
 }

/****************************************************************************
 * do_cmos_writes
 *
 * 'list' is a linked list of pending CMOS write operations that have passed
 * all sanity checks.  Perform all write operations, destroying the list as
 * we go.
 ****************************************************************************/
void do_cmos_writes (cmos_write_t *list)
 { cmos_write_t *item;

   set_iopl(3);

   while (list != NULL)
    { item = list;
      list = item->next;
      cmos_write(item->bit, item->length, item->value);
      free(item);
    }

   cmos_checksum_write(cmos_checksum_compute());
   set_iopl(0);
 }

/****************************************************************************
 * get_input_file_line
 *
 * Get a line of input from file 'f'.  Store result in 'line' which is an
 * array of 'line_buf_size' bytes.  Return OK on success or an error code on
 * error.
 ****************************************************************************/
static int get_input_file_line (FILE *f, char line[], int line_buf_size)
 { switch (get_line_from_file(f, line, line_buf_size))
    { case OK:
         return OK;

      case LINE_EOF:
         return LINE_EOF;

      case LINE_TOO_LONG:
         fprintf(stderr, "%s: Error on line %d of input file: Maximum line "
                 "length exceeded.  Max is %d characters.\n", prog_name,
                 line_num, line_buf_size - 2);
         break;

      default:
         BUG();
    }

   exit(1);
   return 1;  /* keep compiler happy */
 }

/****************************************************************************
 * try_prepare_cmos_write
 *
 * Attempt to convert 'value_str' to an integer representation for storage in
 * CMOS memory.  On success, return the converted value.  On error, exit with
 * an error message.
 ****************************************************************************/
static unsigned long long try_prepare_cmos_write (const cmos_entry_t *e,
                                                  const char value_str[])
 { unsigned long long value;

   switch (prepare_cmos_write(e, value_str, &value))
    { case OK:
         return value;

      case CMOS_OP_BAD_ENUM_VALUE:
         fprintf(stderr, "%s: Error on line %d of input file: Bad value for "
                 "parameter %s.", prog_name, line_num, e->name);
         break;

      case CMOS_OP_NEGATIVE_INT:
         fprintf(stderr, "%s: Error on line %d of input file: This program "
                 "does not support assignment of negative numbers to "
                 "coreboot parameters.", prog_name, line_num);
         break;

      case CMOS_OP_INVALID_INT:
         fprintf(stderr, "%s: Error on line %d of input file: %s is not a "
                 "valid integer.", prog_name, line_num, value_str);
         break;

      case CMOS_OP_RESERVED:
         fprintf(stderr, "%s: Error on line %d of input file: Can not modify "
                 "reserved coreboot parameter %s.", prog_name, line_num,
                 e->name);
         break;

      case CMOS_OP_VALUE_TOO_WIDE:
         fprintf(stderr, "%s: Error on line %d of input file: Can not write "
                 "value %s to CMOS parameter %s that is only %d bits wide.",
                 prog_name, line_num, value_str, e->name, e->length);
         break;

      case CMOS_OP_NO_MATCHING_ENUM:
         fprintf(stderr, "%s: coreboot parameter %s has no matching enums.",
                 prog_name, e->name);
         break;

      case CMOS_AREA_OUT_OF_RANGE:
         fprintf(stderr, "%s: The CMOS area specified by the layout info for "
                 "coreboot parameter %s is out of range.", prog_name,
                 e->name);
         break;

      case CMOS_AREA_OVERLAPS_RTC:
         fprintf(stderr, "%s: The CMOS area specified by the layout info for "
                 "coreboot parameter %s overlaps the realtime clock area.",
                 prog_name, e->name);
         break;

      case CMOS_AREA_TOO_WIDE:
         fprintf(stderr, "%s: The CMOS area specified by the layout info for "
                 "coreboot parameter %s is too wide.",
                 prog_name, e->name);
         break;

      default:
         fprintf(stderr,
                 "%s: Unknown error encountered while attempting to modify "
                 "coreboot parameter %s.", prog_name, e->name);
         break;
    }

   fprintf(stderr, "  No CMOS writes performed.\n");
   exit(1);
   return 0;  /* keep compiler happy */
 }