util/nvramtool/lbtable.c

/*****************************************************************************\
 * lbtable.c
 *****************************************************************************
 *  Copyright (C) 2002-2005 The Regents of the University of California.
 *  Produced at the Lawrence Livermore National Laboratory.
 *  Written by Dave Peterson <dsp@llnl.gov> <dave_peterson@pobox.com>
 *  and Stefan Reinauer <stepan@openbios.org>.
 *  UCRL-CODE-2003-012
 *  All rights reserved.
 *
 *  This file is part of nvramtool, a utility for reading/writing coreboot
 *  parameters and displaying information from the coreboot table.
 *  For details, see http://coreboot.org/nvramtool.
 *
 *  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 <string.h>
#include <sys/mman.h>
#include "common.h"
#include "coreboot_tables.h"
#include "ip_checksum.h"
#include "lbtable.h"
#include "layout.h"
#include "cmos_lowlevel.h"
#include "hexdump.h"

typedef void (*lbtable_print_fn_t) (const struct lb_record *rec);

/* This structure represents an item in the coreboot table that may be
 * displayed using the -l option.
 */
typedef struct
 { uint32_t tag;
   const char *name;
   const char *description;
   const char *nofound_msg;
   lbtable_print_fn_t print_fn;
 }
lbtable_choice_t;

typedef struct
 { unsigned long start;  /* address of first byte of memory range */
   unsigned long end;  /* address of last byte of memory range */
 }
mem_range_t;

static const struct lb_header * lbtable_scan (unsigned long start,
                                              unsigned long end,
                                              int *bad_header_count,
                                              int *bad_table_count);
static void process_cmos_table (void);
static void get_cmos_checksum_info (void);
static void try_convert_checksum_layout (cmos_checksum_layout_t *layout);
static void try_add_cmos_table_enum (cmos_enum_t *cmos_enum);
static void try_add_cmos_table_entry (cmos_entry_t *cmos_entry);
static const struct lb_record * find_lbrec (uint32_t tag);
static const char * lbrec_tag_to_str (uint32_t tag);
static const struct cmos_entries * first_cmos_table_entry (void);
static const struct cmos_entries *
      next_cmos_table_entry (const struct cmos_entries *last);
static const struct cmos_enums * first_cmos_table_enum (void);
static const struct cmos_enums * next_cmos_table_enum
      (const struct cmos_enums *last);
static const struct lb_record * first_cmos_rec (uint32_t tag);
static const struct lb_record * next_cmos_rec (const struct lb_record *last,
                                               uint32_t tag);
static void memory_print_fn (const struct lb_record *rec);
static void mainboard_print_fn (const struct lb_record *rec);
static void cmos_opt_table_print_fn (const struct lb_record *rec);
static void print_option_record (const struct cmos_entries *cmos_entry);
static void print_enum_record (const struct cmos_enums *cmos_enum);
static void print_defaults_record (const struct cmos_defaults *cmos_defaults);
static void print_unknown_record (const struct lb_record *cmos_item);
static void option_checksum_print_fn (const struct lb_record *rec);
static void string_print_fn (const struct lb_record *rec);
static void uint64_to_hex_string (char str[], uint64_t n);

static const char memory_desc[] =
"    This shows information about system memory.\n";

static const char mainboard_desc[] =
"    This shows information about your mainboard.\n";

static const char version_desc[] =
"    This shows coreboot version information.\n";

static const char extra_version_desc[] =
"    This shows extra coreboot version information.\n";

static const char build_desc[] =
"    This shows coreboot build information.\n";

static const char compile_time_desc[] =
"    This shows when coreboot was compiled.\n";

static const char compile_by_desc[] =
"    This shows who compiled coreboot.\n";

static const char compile_host_desc[] =
"    This shows the name of the machine that compiled coreboot.\n";

static const char compile_domain_desc[] =
"    This shows the domain name of the machine that compiled coreboot.\n";

static const char compiler_desc[] =
"    This shows the name of the compiler used to build coreboot.\n";

static const char linker_desc[] =
"    This shows the name of the linker used to build coreboot.\n";

static const char assembler_desc[] =
"    This shows the name of the assembler used to build coreboot.\n";

static const char cmos_opt_table_desc[] =
"    This does a low-level dump of the CMOS option table.  The table "
"contains\n"
"    information about the layout of the values that coreboot stores in\n"
"    nonvolatile RAM.\n";

static const char option_checksum_desc[] =
"    This shows the location of the CMOS checksum and the area over which it "
"is\n"
"    calculated.\n";

static const char generic_nofound_msg[] =
"%s: Item %s not found in coreboot table.\n";

static const char nofound_msg_cmos_opt_table[] =
"%s: Item %s not found in coreboot table.  Apparently, the "
"coreboot installed on this system was built without specifying "
"HAVE_OPTION_TABLE.\n";

static const char nofound_msg_option_checksum[] =
"%s: Item %s not found in coreboot table. Apparently, you are "
"using coreboot v1.\n";

/* This is the number of items from the coreboot table that may be displayed
 * using the -l option.
 */
#define NUM_LBTABLE_CHOICES 14

/* These represent the various items from the coreboot table that may be
 * displayed using the -l option.
 */
static const lbtable_choice_t lbtable_choices[NUM_LBTABLE_CHOICES] =
 { { LB_TAG_MEMORY,            "memory",
     memory_desc,              generic_nofound_msg,
     memory_print_fn
   },
   { LB_TAG_MAINBOARD,         "mainboard",
     mainboard_desc,           generic_nofound_msg,
     mainboard_print_fn
   },
   { LB_TAG_VERSION,           "version",
     version_desc,             generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_EXTRA_VERSION,     "extra_version",
     extra_version_desc,       generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_BUILD,             "build",
     build_desc,               generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_COMPILE_TIME,      "compile_time",
     compile_time_desc,        generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_COMPILE_BY,        "compile_by",
     compile_by_desc,          generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_COMPILE_HOST,      "compile_host",
     compile_host_desc,        generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_COMPILE_DOMAIN,    "compile_domain",
     compile_domain_desc,      generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_COMPILER,          "compiler",
     compiler_desc,            generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_LINKER,            "linker",
     linker_desc,              generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_ASSEMBLER,         "assembler",
     assembler_desc,           generic_nofound_msg,
     string_print_fn
   },
   { LB_TAG_CMOS_OPTION_TABLE, "cmos_opt_table",
     cmos_opt_table_desc,      nofound_msg_cmos_opt_table,
     cmos_opt_table_print_fn
   },
   { LB_TAG_OPTION_CHECKSUM, "option_checksum",
     option_checksum_desc,     nofound_msg_option_checksum,
     option_checksum_print_fn
   }
 };

/* The coreboot table resides in low physical memory, which we access using
 * /dev/mem.  These are ranges of physical memory that should be scanned for a
 * coreboot table.
 */

#define NUM_MEM_RANGES 2

static const mem_range_t mem_ranges[NUM_MEM_RANGES] =
 { { 0x00000000, 0x00000fff },
   { 0x000f0000, 0x000fffff }
 };

/* This is the number of bytes of physical memory to map, starting at physical
 * address 0.  This value must be large enough to contain all memory ranges
 * specified in mem_ranges above plus the maximum possible size of the
 * coreboot table (since the start of the table could potentially occur at
 * the end of the last memory range).
 */
static const size_t BYTES_TO_MAP = (1024 * 1024);

/* Pointer to low physical memory that we access by calling mmap() on
 * /dev/mem.
 */
static const void *low_phys_mem;

/* Pointer to coreboot table. */
static const struct lb_header *lbtable = NULL;

/* The CMOS option table is located within the coreboot table.  It tells us
 * where the CMOS parameters are located in the nonvolatile RAM.
 */
static const struct cmos_option_table *cmos_table = NULL;

static const hexdump_format_t format =
 { 12, 4, "            ", " | ", " ", " | ", '.', NULL };

/****************************************************************************
 * vtophys
 *
 * Convert a virtual address to a physical address.  'vaddr' is a virtual
 * address in the address space of the current process.  It points to
 * somewhere in the chunk of memory that we mapped by calling mmap() on
 * /dev/mem.  This macro converts 'vaddr' to a physical address.
 ****************************************************************************/
#define vtophys(vaddr) (((unsigned long) vaddr) -       \
                        ((unsigned long) low_phys_mem))

/****************************************************************************
 * phystov
 *
 * Convert a physical address to a virtual address.  'paddr' is a physical
 * address.  This macro converts 'paddr' to a virtual address in the address
 * space of the current process.  The virtual to physical mapping was set up
 * by calling mmap() on /dev/mem.
 ****************************************************************************/
#define phystov(paddr) (((unsigned long) low_phys_mem) + \
                        ((unsigned long) paddr))

/****************************************************************************
 * get_lbtable
 *
 * Find the coreboot table and set global variable lbtable to point to it.
 ****************************************************************************/
void get_lbtable (void)
 { int fd, i, bad_header_count, bad_table_count, bad_headers, bad_tables;

   if (lbtable != NULL)
      return;

   /* The coreboot table is located in low physical memory, which may be
    * conveniently accessed by calling mmap() on /dev/mem.
    */

   if ((fd = open("/dev/mem", O_RDONLY, 0)) < 0)
    { fprintf(stderr, "%s: Can not open /dev/mem for reading: %s\n",
              prog_name, strerror(errno));
      exit(1);
    }

   if ((low_phys_mem = mmap(NULL, BYTES_TO_MAP, PROT_READ, MAP_SHARED, fd, 0))
       == MAP_FAILED)
    { fprintf(stderr, "%s: Failed to mmap /dev/mem: %s\n", prog_name,
              strerror(errno));
      exit(1);
    }

   bad_header_count = 0;
   bad_table_count = 0;

   for (i = 0; i < NUM_MEM_RANGES; i++)
    { lbtable = lbtable_scan(phystov(mem_ranges[i].start),
                             phystov(mem_ranges[i].end),
                             &bad_headers, &bad_tables);

      if (lbtable != NULL)
         return; /* success: we found it! */

      bad_header_count += bad_headers;
      bad_table_count += bad_tables;
    }

   fprintf(stderr,
           "%s: coreboot table not found.  coreboot does not appear to\n"
           "        be installed on this system.  Scanning for the table "
           "produced the\n"
           "        following results:\n\n"
           "            %d valid signatures were found with bad header "
           "checksums.\n"
           "            %d valid headers were found with bad table "
           "checksums.\n",
           prog_name, bad_header_count, bad_table_count);
   exit(1);
 }

/****************************************************************************
 * get_layout_from_cmos_table
 *
 * Find the CMOS table which is stored within the coreboot table and set the
 * global variable cmos_table to point to it.
 ****************************************************************************/
void get_layout_from_cmos_table (void)
 {

   get_lbtable();
   cmos_table = (const struct cmos_option_table *)
                find_lbrec(LB_TAG_CMOS_OPTION_TABLE);

   if ((cmos_table) == NULL)
    { fprintf(stderr,
              "%s: CMOS option table not found in coreboot table.  "
              "Apparently, the coreboot installed on this system was "
              "built without specifying HAVE_OPTION_TABLE.\n",
              prog_name);
      exit(1);
    }

   process_cmos_table();
   get_cmos_checksum_info();
 }

/****************************************************************************
 * dump_lbtable
 *
 * Do a low-level dump of the coreboot table.
 ****************************************************************************/
void dump_lbtable (void)
 { const char *p, *data;
   uint32_t bytes_processed;
   const struct lb_record *lbrec;

   p = ((const char *) lbtable) + lbtable->header_bytes;
   printf("Coreboot table at physical address 0x%lx:\n"
          "    signature:       0x%x (ASCII: %c%c%c%c)\n"
          "    header_bytes:    0x%x (decimal: %d)\n"
          "    header_checksum: 0x%x (decimal: %d)\n"
          "    table_bytes:     0x%x (decimal: %d)\n"
          "    table_checksum:  0x%x (decimal: %d)\n"
          "    table_entries:   0x%x (decimal: %d)\n\n",
          vtophys(lbtable), *((uint32_t *) lbtable->signature),
          lbtable->signature[0], lbtable->signature[1],lbtable->signature[2],
          lbtable->signature[3], lbtable->header_bytes, lbtable->header_bytes,
          lbtable->header_checksum, lbtable->header_checksum,
          lbtable->table_bytes, lbtable->table_bytes, lbtable->table_checksum,
          lbtable->table_checksum, lbtable->table_entries,
          lbtable->table_entries);

   if ((lbtable->table_bytes == 0) != (lbtable->table_entries == 0))
    { printf("Inconsistent values for table_bytes and table_entries!!!\n"
             "They should be either both 0 or both nonzero.\n");
      return;
    }

   if (lbtable->table_bytes == 0)
    { printf("The coreboot table is empty!!!\n");
      return;
    }

   for (bytes_processed = 0; ; )
    { lbrec = (const struct lb_record *) &p[bytes_processed];
      printf("    %s record at physical address 0x%lx:\n"
             "        tag:  0x%x (decimal: %d)\n"
             "        size: 0x%x (decimal: %d)\n"
             "        data:\n",
             lbrec_tag_to_str(lbrec->tag), vtophys(lbrec), lbrec->tag,
             lbrec->tag, lbrec->size, lbrec->size);

      data = ((const char *) lbrec) + sizeof(*lbrec);
      hexdump(data, lbrec->size - sizeof(*lbrec), vtophys(data), stdout,
              &format);

      bytes_processed += lbrec->size;

      if (bytes_processed >= lbtable->table_bytes)
         break;

      printf("\n");
    }
 }

/****************************************************************************
 * list_lbtable_choices
 *
 * List names and informational blurbs for items from the coreboot table
 * that may be displayed using the -l option.
 ****************************************************************************/
void list_lbtable_choices (void)
 { int i;

   for (i = 0; ; )
    { printf("%s:\n%s",
             lbtable_choices[i].name, lbtable_choices[i].description);

      if (++i >= NUM_LBTABLE_CHOICES)
         break;

      printf("\n");
    }
 }

/****************************************************************************
 * list_lbtable_item
 *
 * Show the coreboot table item specified by 'item'.
 ****************************************************************************/
void list_lbtable_item (const char item[])
 { int i;
   const struct lb_record *rec;

   for (i = 0; i < NUM_LBTABLE_CHOICES; i++)
    { if (strcmp(item, lbtable_choices[i].name) == 0)
         break;
    }

   if (i == NUM_LBTABLE_CHOICES)
    { fprintf(stderr, "%s: Invalid coreboot table item %s.\n", prog_name,
              item);
      exit(1);
    }

   if ((rec = find_lbrec(lbtable_choices[i].tag)) == NULL)
    { fprintf(stderr, lbtable_choices[i].nofound_msg, prog_name,
              lbtable_choices[i].name);
      exit(1);
    }

   lbtable_choices[i].print_fn(rec);
 }

/****************************************************************************
 * lbtable_scan
 *
 * Scan the chunk of memory specified by 'start' and 'end' for a coreboot
 * table.  The first 4 bytes of the table are marked by the signature
 * { 'L', 'B', 'I', 'O' }.  'start' and 'end' indicate the addresses of the
 * first and last bytes of the chunk of memory to be scanned.  For instance,
 * values of 0x10000000 and 0x1000ffff for 'start' and 'end' specify a 64k
 * chunk of memory starting at address 0x10000000.  'start' and 'end' are
 * virtual addresses in the address space of the current process.  They
 * represent a chunk of memory obtained by calling mmap() on /dev/mem.
 *
 * If a coreboot table is found, return a pointer to it.  Otherwise return
 * NULL.  On return, *bad_header_count and *bad_table_count are set as
 * follows:
 *
 *     *bad_header_count:
 *         Indicates the number of times in which a valid signature was found
 *         but the header checksum was invalid.
 *
 *     *bad_table_count:
 *         Indicates the number of times in which a header with a valid
 *         checksum was found but the table checksum was invalid.
 ****************************************************************************/
static const struct lb_header * lbtable_scan (unsigned long start,
                                              unsigned long end,
                                              int *bad_header_count,
                                              int *bad_table_count)
 { static const char signature[] = { 'L', 'B', 'I', 'O' };
   const struct lb_header *table;
   const uint32_t *p;
   uint32_t sig;

   assert(end >= start);
   sig = (*((const uint32_t *) signature));
   table = NULL;
   *bad_header_count = 0;
   *bad_table_count = 0;

   /* Look for signature.  Table is aligned on 16-byte boundary.  Therefore
    * only check every fourth 32-bit memory word.  As the loop is coded below,
    * this function will behave in a reasonable manner for ALL possible values
    * for 'start' and 'end': even weird boundary cases like 0x00000000 and
    * 0xffffffff on a 32-bit architecture.
    */
   for (p = (const uint32_t *) start;
        (((unsigned long) p) <= end) &&
        ((end - (unsigned long) p) >= (sizeof(uint32_t) - 1));
        p += 4)
    { if (*p != sig)
         continue;

      /* We found a valid signature. */
      table = (const struct lb_header *) p;

      /* validate header checksum */
      if (compute_ip_checksum((void *) table, sizeof(*table)))
       { (*bad_header_count)++;
         continue;
       }

      /* validate table checksum */
      if (table->table_checksum !=
          compute_ip_checksum(((char *) table) + sizeof(*table),
                              table->table_bytes))
       { (*bad_table_count)++;
         continue;
       }

      /* checksums are ok: we found it! */
      return table;
    }

   return NULL;
 }

/****************************************************************************
 * process_cmos_table
 *
 * Extract layout information from the CMOS option table and store it in our
 * internal repository.
 ****************************************************************************/
static void process_cmos_table (void)
 { const struct cmos_enums *p;
   const struct cmos_entries *q;
   cmos_enum_t cmos_enum;
   cmos_entry_t cmos_entry;

   /* First add the enums. */
   for (p = first_cmos_table_enum(); p != NULL; p = next_cmos_table_enum(p))
    { cmos_enum.config_id = p->config_id;
      cmos_enum.value = p->value;
      strncpy(cmos_enum.text, (char *)p->text, CMOS_MAX_TEXT_LENGTH);
      cmos_enum.text[CMOS_MAX_TEXT_LENGTH] = '\0';
      try_add_cmos_table_enum(&cmos_enum);
    }

   /* Now add the entries.  We must add the entries after the enums because
    * the entries are sanity checked against the enums as they are added.
    */
   for (q = first_cmos_table_entry(); q != NULL; q = next_cmos_table_entry(q))
    { cmos_entry.bit = q->bit;
      cmos_entry.length = q->length;

      switch (q->config)
       { case 'e':
            cmos_entry.config = CMOS_ENTRY_ENUM;
            break;

         case 'h':
            cmos_entry.config = CMOS_ENTRY_HEX;
            break;

         case 'r':
            cmos_entry.config = CMOS_ENTRY_RESERVED;
            break;

         case 's':
            cmos_entry.config = CMOS_ENTRY_STRING;
            break;

         default:
            fprintf(stderr,
                    "%s: Entry in CMOS option table has unknown config "
                    "value.\n", prog_name);
            exit(1);
       }

      cmos_entry.config_id = q->config_id;
      strncpy(cmos_entry.name, (char *)q->name, CMOS_MAX_NAME_LENGTH);
      cmos_entry.name[CMOS_MAX_NAME_LENGTH] = '\0';
      try_add_cmos_table_entry(&cmos_entry);
    }
 }

/****************************************************************************
 * get_cmos_checksum_info
 *
 * Get layout information for CMOS checksum.
 ****************************************************************************/
static void get_cmos_checksum_info (void)
 { const cmos_entry_t *e;
   struct cmos_checksum *checksum;
   cmos_checksum_layout_t layout;
   unsigned index, index2;

   checksum = (struct cmos_checksum *) find_lbrec(LB_TAG_OPTION_CHECKSUM);

   if (checksum != NULL)
    { /* We are lucky.  The coreboot table hints us to the checksum.
       * We might have to check the type field here though.
       */
      layout.summed_area_start = checksum->range_start;
      layout.summed_area_end = checksum->range_end;
      layout.checksum_at = checksum->location;
      try_convert_checksum_layout(&layout);
      cmos_checksum_start = layout.summed_area_start;
      cmos_checksum_end = layout.summed_area_end;
      cmos_checksum_index = layout.checksum_at;
      return;
    }

   if ((e = find_cmos_entry(checksum_param_name)) == NULL)
      return;

   /* If we get here, we are unlucky.  The CMOS option table contains the
    * location of the CMOS checksum.  However, there is no information
    * regarding which bytes of the CMOS area the checksum is computed over.
    * Thus we have to hope our presets will be fine.
    */

   if (e->bit % 8)
    { fprintf(stderr, "%s: Error: CMOS checksum is not byte-aligned.\n",
              prog_name);
      exit(1);
    }

   index = e->bit / 8;
   index2 = index + 1;  /* The CMOS checksum occupies 16 bits. */

   if (verify_cmos_byte_index(index) || verify_cmos_byte_index(index2))
    { fprintf(stderr, "%s: Error: CMOS checksum location out of range.\n",
              prog_name);
      exit(1);
    }

   if (((index >= cmos_checksum_start) && (index <= cmos_checksum_end)) ||
       (((index2) >= cmos_checksum_start) && ((index2) <= cmos_checksum_end)))
    { fprintf(stderr, "%s: Error: CMOS checksum overlaps checksummed area.\n",
              prog_name);
      exit(1);
    }

   cmos_checksum_index = index;
 }

/****************************************************************************
 * try_convert_checksum_layout
 *
 * Perform sanity checking on CMOS checksum layout information and attempt to
 * convert information from bit positions to byte positions.  Return OK on
 * success or an error code on failure.
 ****************************************************************************/
static void try_convert_checksum_layout (cmos_checksum_layout_t *layout)
 { switch (checksum_layout_to_bytes(layout))
    { case OK:
         return;

      case LAYOUT_SUMMED_AREA_START_NOT_ALIGNED:
         fprintf(stderr,
                 "%s: CMOS checksummed area start is not byte-aligned.\n",
                 prog_name);
         break;

      case LAYOUT_SUMMED_AREA_END_NOT_ALIGNED:
         fprintf(stderr,
                 "%s: CMOS checksummed area end is not byte-aligned.\n",
                 prog_name);
         break;

      case LAYOUT_CHECKSUM_LOCATION_NOT_ALIGNED:
         fprintf(stderr,
                 "%s: CMOS checksum location is not byte-aligned.\n",
                 prog_name);
         break;

      case LAYOUT_INVALID_SUMMED_AREA:
         fprintf(stderr,
                 "%s: CMOS checksummed area end must be greater than "
                 "CMOS checksummed area start.\n",
                 prog_name);
         break;

      case LAYOUT_CHECKSUM_OVERLAPS_SUMMED_AREA:
         fprintf(stderr,
                 "%s: CMOS checksum overlaps checksummed area.\n",
                 prog_name);
         break;

      case LAYOUT_SUMMED_AREA_OUT_OF_RANGE:
         fprintf(stderr,
                 "%s: CMOS checksummed area out of range.\n",
                 prog_name);
         break;

      case LAYOUT_CHECKSUM_LOCATION_OUT_OF_RANGE:
         fprintf(stderr,
                 "%s: CMOS checksum location out of range.\n",
                 prog_name);
         break;

      default:
         BUG();
    }

   exit(1);
 }

/****************************************************************************
 * try_add_cmos_table_enum
 *
 * Attempt to add a CMOS enum to our internal repository.  Exit with an error
 * message on failure.
 ****************************************************************************/
static void try_add_cmos_table_enum (cmos_enum_t *cmos_enum)
 { switch (add_cmos_enum(cmos_enum))
    { case OK:
         return;

      case LAYOUT_DUPLICATE_ENUM:
         fprintf(stderr, "%s: Duplicate enum %s found in CMOS option "
                 "table.\n", prog_name, cmos_enum->text);
         break;

      default:
         BUG();
    }

   exit(1);
 }

/****************************************************************************
 * try_add_cmos_table_entry
 *
 * Attempt to add a CMOS entry to our internal repository.  Exit with an
 * error message on failure.
 ****************************************************************************/
static void try_add_cmos_table_entry (cmos_entry_t *cmos_entry)
 { const cmos_entry_t *conflict;

   switch (add_cmos_entry(cmos_entry, &conflict))
    { case OK:
         return;

      case CMOS_AREA_OUT_OF_RANGE:
         fprintf(stderr,
                 "%s: Bad CMOS option layout in CMOS option table entry "
                 "%s.\n", prog_name, cmos_entry->name);
         break;

      case CMOS_AREA_TOO_WIDE:
         fprintf(stderr,
                 "%s: Area too wide for CMOS option table entry %s.\n",
                 prog_name, cmos_entry->name);
         break;

      case LAYOUT_ENTRY_OVERLAP:
         fprintf(stderr,
                 "%s: CMOS option table entries %s and %s have overlapping "
                 "layouts.\n", prog_name, cmos_entry->name, conflict->name);
         break;

      case LAYOUT_ENTRY_BAD_LENGTH:
         /* Silently ignore entries with zero length.  Although this should
          * never happen in practice, we should handle the case in a
          * reasonable manner just to be safe.
          */
         return;

      default:
         BUG();
    }

   exit(1);
 }

/****************************************************************************
 * find_lbrec
 *
 * Find the record in the coreboot table that matches 'tag'.  Return pointer
 * to record on success or NULL if record not found.
 ****************************************************************************/
static const struct lb_record * find_lbrec (uint32_t tag)
 { const char *p;
   uint32_t bytes_processed;
   const struct lb_record *lbrec;

   p = ((const char *) lbtable) + lbtable->header_bytes;

   for (bytes_processed = 0;
        bytes_processed < lbtable->table_bytes;
        bytes_processed += lbrec->size)
    { lbrec = (const struct lb_record *) &p[bytes_processed];

      if (lbrec->tag == tag)
         return lbrec;
    }

   return NULL;
 }

/****************************************************************************
 * lbrec_tag_to_str
 *
 * Return a pointer to the string representation of the given coreboot table
 * tag.
 ****************************************************************************/
static const char * lbrec_tag_to_str (uint32_t tag)
 { switch (tag)
    { case LB_TAG_UNUSED:
         return "UNUSED";

      case LB_TAG_MEMORY:
         return "MEMORY";

      case LB_TAG_HWRPB:
         return "HWRPB";

      case LB_TAG_MAINBOARD:
         return "MAINBOARD";

      case LB_TAG_VERSION:
         return "VERSION";

      case LB_TAG_EXTRA_VERSION:
         return "EXTRA_VERSION";

      case LB_TAG_BUILD:
         return "BUILD";

      case LB_TAG_COMPILE_TIME:
         return "COMPILE_TIME";

      case LB_TAG_COMPILE_BY:
         return "COMPILE_BY";

      case LB_TAG_COMPILE_HOST:
         return "COMPILE_HOST";

      case LB_TAG_COMPILE_DOMAIN:
         return "COMPILE_DOMAIN";

      case LB_TAG_COMPILER:
         return "COMPILER";

      case LB_TAG_LINKER:
         return "LINKER";

      case LB_TAG_ASSEMBLER:
         return "ASSEMBLER";

      case LB_TAG_CMOS_OPTION_TABLE:
         return "CMOS_OPTION_TABLE";

      case LB_TAG_OPTION_CHECKSUM:
         return "OPTION_CHECKSUM";

      default:
         break;
    }

   return "UNKNOWN";
 }

/****************************************************************************
 * first_cmos_table_entry
 *
 * Return a pointer to the first entry in the CMOS table that represents a
 * CMOS parameter.  Return NULL if CMOS table is empty.
 ****************************************************************************/
static const struct cmos_entries * first_cmos_table_entry (void)
 { return (const struct cmos_entries *) first_cmos_rec(LB_TAG_OPTION); }

/****************************************************************************
 * next_cmos_table_entry
 *
 * Return a pointer to the next entry after 'last' in the CMOS table that
 * represents a CMOS parameter.  Return NULL if there are no more parameters.
 ****************************************************************************/
static const struct cmos_entries *
      next_cmos_table_entry (const struct cmos_entries *last)
 { return (const struct cmos_entries *)
          next_cmos_rec((const struct lb_record *) last, LB_TAG_OPTION);
 }

/****************************************************************************
 * first_cmos_table_enum
 *
 * Return a pointer to the first entry in the CMOS table that represents a
 * possible CMOS parameter value.  Return NULL if the table does not contain
 * any such entries.
 ****************************************************************************/
static const struct cmos_enums * first_cmos_table_enum (void)
 { return (const struct cmos_enums *) first_cmos_rec(LB_TAG_OPTION_ENUM); }

/****************************************************************************
 * next_cmos_table_enum
 *
 * Return a pointer to the next entry after 'last' in the CMOS table that
 * represents a possible CMOS parameter value.  Return NULL if there are no
 * more parameter values.
 ****************************************************************************/
static const struct cmos_enums * next_cmos_table_enum
      (const struct cmos_enums *last)
 { return (const struct cmos_enums *)
          next_cmos_rec((const struct lb_record *) last, LB_TAG_OPTION_ENUM);
 }

/****************************************************************************
 * first_cmos_rec
 *
 * Return a pointer to the first entry in the CMOS table whose type matches
 * 'tag'.  Return NULL if CMOS table contains no such entry.
 *
 * Possible values for 'tag' are as follows:
 *
 *     LB_TAG_OPTION:      The entry represents a CMOS parameter.
 *     LB_TAG_OPTION_ENUM: The entry represents a possible value for a CMOS
 *                         parameter of type 'enum'.
 *
 * The CMOS table tells us where in the nonvolatile RAM to look for CMOS
 * parameter values and specifies their types as 'enum', 'hex', or
 * 'reserved'.
 ****************************************************************************/
static const struct lb_record * first_cmos_rec (uint32_t tag)
 { const char             *p;
   uint32_t               bytes_processed, bytes_for_entries;
   const struct lb_record *lbrec;

   p = ((const char *) cmos_table) + cmos_table->header_length;
   bytes_for_entries = cmos_table->size - cmos_table->header_length;

   for (bytes_processed = 0;
        bytes_processed < bytes_for_entries;
        bytes_processed += lbrec->size)
    { lbrec = (const struct lb_record *) &p[bytes_processed];

      if (lbrec->tag == tag)
         return lbrec;
    }

   return NULL;
 }

/****************************************************************************
 * next_cmos_rec
 *
 * Return a pointer to the next entry after 'last' in the CMOS table whose
 * type matches 'tag'.  Return NULL if the table contains no more entries of
 * this type.
 ****************************************************************************/
static const struct lb_record * next_cmos_rec (const struct lb_record *last,
                                               uint32_t tag)
 { const char *p;
   uint32_t bytes_processed, bytes_for_entries, last_offset;
   const struct lb_record *lbrec;

   p = ((const char *) cmos_table) + cmos_table->header_length;
   bytes_for_entries = cmos_table->size - cmos_table->header_length;
   last_offset = ((const char *) last) - p;

   for (bytes_processed = last_offset + last->size;
        bytes_processed < bytes_for_entries;
        bytes_processed += lbrec->size)
    { lbrec = (const struct lb_record *) &p[bytes_processed];

      if (lbrec->tag == tag)
         return lbrec;
    }

   return NULL;
 }

/****************************************************************************
 * memory_print_fn
 *
 * Display function for 'memory' item of coreboot table.
 ****************************************************************************/
static void memory_print_fn (const struct lb_record *rec)
 { char start_str[19], end_str[19], size_str[19];
   const struct lb_memory *p;
   const char *mem_type;
   const struct lb_memory_range *ranges;
   uint64_t size, start, end;
   int i, entries;

   p = (const struct lb_memory *) rec;
   entries = (p->size -  sizeof(*p)) / sizeof(p->map[0]);
   ranges = p->map;

   if (entries == 0)
    { printf("No memory ranges were found.\n");
      return;
    }

   for (i = 0; ; )
    { switch (ranges[i].type)
       { case LB_MEM_RAM:
            mem_type = "AVAILABLE";
            break;

         case LB_MEM_RESERVED:
            mem_type = "RESERVED";
            break;

         case LB_MEM_TABLE:
            mem_type = "CONFIG_TABLE";
            break;

         default:
            mem_type = "UNKNOWN";
            break;
       }

      size = unpack_lb64(ranges[i].size);
      start = unpack_lb64(ranges[i].start);
      end  = start + size - 1;
      uint64_to_hex_string(start_str, start);
      uint64_to_hex_string(end_str, end);
      uint64_to_hex_string(size_str, size);
      printf("%s memory:\n"
             "    from physical addresses %s to %s\n"
             "    size is %s bytes (%lld in decimal)\n",
             mem_type, start_str, end_str, size_str,
             (unsigned long long) size);

      if (++i >= entries)
         break;

      printf("\n");
    }
 }

/****************************************************************************
 * mainboard_print_fn
 *
 * Display function for 'mainboard' item of coreboot table.
 ****************************************************************************/
static void mainboard_print_fn (const struct lb_record *rec)
 { const struct lb_mainboard *p;

   p = (const struct lb_mainboard *) rec;
   printf("Vendor:      %s\n"
          "Part number: %s\n",
          &p->strings[p->vendor_idx],
          &p->strings[p->part_number_idx]);
 }

/****************************************************************************
 * cmos_opt_table_print_fn
 *
 * Display function for 'cmos_opt_table' item of coreboot table.
 ****************************************************************************/
static void cmos_opt_table_print_fn (const struct lb_record *rec)
 {
   const struct cmos_option_table *p;
   const struct lb_record *cmos_item;
   uint32_t bytes_processed, bytes_for_entries;
   const char *q;

   p = (const struct cmos_option_table *) rec;
   q = ((const char *) p) + p->header_length;
   bytes_for_entries = p->size - p->header_length;

   printf("CMOS option table at physical address 0x%lx:\n"
          "    tag:           0x%x (decimal: %d)\n"
          "    size:          0x%x (decimal: %d)\n"
          "    header_length: 0x%x (decimal: %d)\n\n",
          vtophys(p), p->tag, p->tag, p->size, p->size, p->header_length,
          p->header_length);

   if (p->header_length > p->size)
    { printf("Header length for CMOS option table is greater than the size "
             "of the entire table including header!!!\n");
      return;
    }

   if (bytes_for_entries == 0)
    { printf("The CMOS option table is empty!!!\n");
      return;
    }

   for (bytes_processed = 0; ; )
    { cmos_item = (const struct lb_record *) &q[bytes_processed];

      switch (cmos_item->tag)
       { case LB_TAG_OPTION:
            print_option_record((const struct cmos_entries *) cmos_item);
            break;

         case LB_TAG_OPTION_ENUM:
            print_enum_record((const struct cmos_enums *) cmos_item);
            break;

         case LB_TAG_OPTION_DEFAULTS:
            print_defaults_record((const struct cmos_defaults *) cmos_item);
            break;

         default:
            print_unknown_record(cmos_item);
            break;
       }

      bytes_processed += cmos_item->size;

      if (bytes_processed >= bytes_for_entries)
         break;

      printf("\n");
    }
 }

/****************************************************************************
 * print_option_record
 *
 * Display "option" record from CMOS option table.
 ****************************************************************************/
static void print_option_record (const struct cmos_entries *cmos_entry)
 { static const size_t S_BUFSIZE = 80;
   char s[S_BUFSIZE];

   switch (cmos_entry->config)
    { case 'e':
         strcpy(s, "ENUM");
         break;

      case 'h':
         strcpy(s, "HEX");
         break;

      case 'r':
         strcpy(s, "RESERVED");
         break;

      default:
         snprintf(s, S_BUFSIZE, "UNKNOWN: value is 0x%x (decimal: %d)",
                  cmos_entry->config, cmos_entry->config);
         break;
    }

   printf("    OPTION record at physical address 0x%lx:\n"
          "        tag:       0x%x (decimal: %d)\n"
          "        size:      0x%x (decimal: %d)\n"
          "        bit:       0x%x (decimal: %d)\n"
          "        length:    0x%x (decimal: %d)\n"
          "        config:    %s\n"
          "        config_id: 0x%x (decimal: %d)\n"
          "        name:      %s\n",
          vtophys(cmos_entry), cmos_entry->tag, cmos_entry->tag,
          cmos_entry->size, cmos_entry->size, cmos_entry->bit,
          cmos_entry->bit, cmos_entry->length, cmos_entry->length, s,
          cmos_entry->config_id, cmos_entry->config_id, cmos_entry->name);
 }

/****************************************************************************
 * print_enum_record
 *
 * Display "enum" record from CMOS option table.
 ****************************************************************************/
static void print_enum_record (const struct cmos_enums *cmos_enum)
 { printf("    ENUM record at physical address 0x%lx:\n"
          "        tag:       0x%x (decimal: %d)\n"
          "        size:      0x%x (decimal: %d)\n"
          "        config_id: 0x%x (decimal: %d)\n"
          "        value:     0x%x (decimal: %d)\n"
          "        text:      %s\n",
          vtophys(cmos_enum), cmos_enum->tag, cmos_enum->tag, cmos_enum->size,
          cmos_enum->size, cmos_enum->config_id, cmos_enum->config_id,
          cmos_enum->value, cmos_enum->value, cmos_enum->text);
 }

/****************************************************************************
 * print_defaults_record
 *
 * Display "defaults" record from CMOS option table.
 ****************************************************************************/
static void print_defaults_record (const struct cmos_defaults *cmos_defaults)
 { printf("    DEFAULTS record at physical address 0x%lx:\n"
          "        tag:         0x%x (decimal: %d)\n"
          "        size:        0x%x (decimal: %d)\n"
          "        name_length: 0x%x (decimal: %d)\n"
          "        name:        %s\n"
          "        default_set:\n",
          vtophys(cmos_defaults), cmos_defaults->tag, cmos_defaults->tag,
          cmos_defaults->size, cmos_defaults->size,
          cmos_defaults->name_length, cmos_defaults->name_length,
          cmos_defaults->name);
   hexdump(cmos_defaults->default_set, CMOS_IMAGE_BUFFER_SIZE,
           vtophys(cmos_defaults->default_set), stdout, &format);
 }

/****************************************************************************
 * print_unknown_record
 *
 * Display record of unknown type from CMOS option table.
 ****************************************************************************/
static void print_unknown_record (const struct lb_record *cmos_item)
 { const char *data;

   printf("    UNKNOWN record at physical address 0x%lx:\n"
          "        tag:  0x%x (decimal: %d)\n"
          "        size: 0x%x (decimal: %d)\n"
          "        data:\n",
          vtophys(cmos_item), cmos_item->tag, cmos_item->tag,
          cmos_item->size, cmos_item->size);
   data = ((const char *) cmos_item) + sizeof(*cmos_item);
   hexdump(data, cmos_item->size - sizeof(*cmos_item), vtophys(data), stdout,
           &format);
 }

/****************************************************************************
 * option_checksum_print_fn
 *
 * Display function for 'option_checksum' item of coreboot table.
 ****************************************************************************/
static void option_checksum_print_fn (const struct lb_record *rec)
 { struct cmos_checksum *p;

   p = (struct cmos_checksum *) rec;
   printf("CMOS checksum from bit %d to bit %d\n"
          "at position %d is type %s.\n",
          p->range_start, p->range_end, p->location,
          (p->type == CHECKSUM_PCBIOS) ? "PC BIOS" : "NONE");
 }

/****************************************************************************
 * string_print_fn
 *
 * Display function for a generic item of coreboot table that simply
 * consists of a string.
 ****************************************************************************/
static void string_print_fn (const struct lb_record *rec)
 { const struct lb_string *p;

   p = (const struct lb_string *) rec;
   printf("%s\n", p->string);
 }

/****************************************************************************
 * uint64_to_hex_string
 *
 * Convert the 64-bit integer 'n' to its hexadecimal string representation,
 * storing the result in 's'.  's' must point to a buffer at least 19 bytes
 * long.  The result is displayed with as many leading zeros as needed to
 * make a 16-digit hex number including a 0x prefix (example: the number 1
 * will be displayed as "0x0000000000000001").
 ****************************************************************************/
static void uint64_to_hex_string (char str[], uint64_t n)
 { int chars_printed;

   str[0] = '0';
   str[1] = 'x';

   /* Print the result right-justified with leading spaces in a
    * 16-character field. */
   chars_printed = sprintf(&str[2], "%016llx", (unsigned long long) n);
   assert(chars_printed == 16);
 }