src/lib/fmap.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright 2012-2015 Google Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <arch/early_variables.h>
  17 #include <boot_device.h>
  18 #include <console/console.h>
  19 #include <fmap.h>
  20 #include <commonlib/fmap_serialized.h>
  21 #include <stddef.h>
  22 #include <string.h>
  23
  24 #include "fmap_config.h"
  25
  26 /*
  27  * See http://code.google.com/p/flashmap/ for more information on FMAP.
  28  */
  29
  30 static int fmap_print_once CAR_GLOBAL;
  31
  32 int find_fmap_directory(struct region_device *fmrd)
  33 {
  34         const struct region_device *boot;
  35         struct fmap *fmap;
  36         size_t fmap_size;
  37         size_t offset = FMAP_OFFSET;
  38
  39         boot_device_init();
  40         boot = boot_device_ro();
  41
  42         if (boot == NULL)
  43                 return -1;
  44
  45         fmap_size = sizeof(struct fmap);
  46
  47         fmap = rdev_mmap(boot, offset, fmap_size);
  48
  49         if (fmap == NULL)
  50                 return -1;
  51
  52         if (memcmp(fmap->signature, FMAP_SIGNATURE, sizeof(fmap->signature))) {
  53                 printk(BIOS_DEBUG, "No FMAP found at %zx offset.\n", offset);
  54                 rdev_munmap(boot, fmap);
  55                 return -1;
  56         }
  57
  58         if (!car_get_var(fmap_print_once)) {
  59                 printk(BIOS_DEBUG, "FMAP: Found \"%s\" version %d.%d at %zx.\n",
  60                        fmap->name, fmap->ver_major, fmap->ver_minor, offset);
  61                 printk(BIOS_DEBUG, "FMAP: base = %llx size = %x #areas = %d\n",
  62                        (long long)fmap->base, fmap->size, fmap->nareas);
  63                 car_set_var(fmap_print_once, 1);
  64         }
  65
  66         fmap_size += fmap->nareas * sizeof(struct fmap_area);
  67
  68         rdev_munmap(boot, fmap);
  69
  70         return rdev_chain(fmrd, boot, offset, fmap_size);
  71 }
  72
  73 int fmap_locate_area_as_rdev(const char *name, struct region_device *area)
  74 {
  75         struct region ar;
  76
  77         if (fmap_locate_area(name, &ar))
  78                 return -1;
  79
  80         return boot_device_ro_subregion(&ar, area);
  81 }
  82
  83 int fmap_locate_area_as_rdev_rw(const char *name, struct region_device *area)
  84 {
  85         struct region ar;
  86
  87         if (fmap_locate_area(name, &ar))
  88                 return -1;
  89
  90         return boot_device_rw_subregion(&ar, area);
  91 }
  92
  93 int fmap_locate_area(const char *name, struct region *ar)
  94 {
  95         struct region_device fmrd;
  96         size_t offset;
  97
  98         if (find_fmap_directory(&fmrd))
  99                 return -1;
 100
 101         /* Start reading the areas just after fmap header. */
 102         offset = sizeof(struct fmap);
 103
 104         while (1) {
 105                 struct fmap_area *area;
 106
 107                 area = rdev_mmap(&fmrd, offset, sizeof(*area));
 108
 109                 if (area == NULL)
 110                         return -1;
 111
 112                 if (strcmp((const char *)area->name, name)) {
 113                         rdev_munmap(&fmrd, area);
 114                         offset += sizeof(struct fmap_area);
 115                         continue;
 116                 }
 117
 118                 printk(BIOS_DEBUG, "FMAP: area %s found @ %x (%d bytes)\n",
 119                        name, area->offset, area->size);
 120
 121                 ar->offset = area->offset;
 122                 ar->size = area->size;
 123
 124                 rdev_munmap(&fmrd, area);
 125
 126                 return 0;
 127         }
 128
 129         printk(BIOS_DEBUG, "FMAP: area %s not found\n", name);
 130
 131         return -1;
 132 }
 133
 134 int fmap_find_region_name(const struct region * const ar,
 135         char name[FMAP_STRLEN])
 136 {
 137         struct region_device fmrd;
 138         size_t offset;
 139
 140         if (find_fmap_directory(&fmrd))
 141                 return -1;
 142
 143         /* Start reading the areas just after fmap header. */
 144         offset = sizeof(struct fmap);
 145
 146         while (1) {
 147                 struct fmap_area *area;
 148
 149                 area = rdev_mmap(&fmrd, offset, sizeof(*area));
 150
 151                 if (area == NULL)
 152                         return -1;
 153
 154                 if ((ar->offset != area->offset) ||
 155                     (ar->size != area->size)) {
 156                         rdev_munmap(&fmrd, area);
 157                         offset += sizeof(struct fmap_area);
 158                         continue;
 159                 }
 160
 161                 printk(BIOS_DEBUG, "FMAP: area (%zx, %zx) found, named %s\n",
 162                         ar->offset, ar->size, area->name);
 163
 164                 memcpy(name, area->name, FMAP_STRLEN);
 165
 166                 rdev_munmap(&fmrd, area);
 167
 168                 return 0;
 169         }
 170
 171         printk(BIOS_DEBUG, "FMAP: area (%zx, %zx) not found\n",
 172                 ar->offset, ar->size);
 173
 174         return -1;
 175 }