package/mtd/src/fis.c

   1 /*
   2  * FIS table updating code for mtd
   3  *
   4  * Copyright (C) 2009 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License v2
   8  * as published by the Free Software Foundation.
   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 #include <sys/mman.h>
  16 #include <stdint.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include "crc32.h"
  22 #include "mtd.h"
  23 #include "fis.h"
  24
  25 struct fis_image_hdr {
  26         unsigned char name[16];
  27         uint32_t flash_base;
  28         uint32_t mem_base;
  29         uint32_t size;
  30         uint32_t entry_point;
  31         uint32_t data_length;
  32 } __attribute__((packed));
  33
  34 struct fis_image_crc {
  35         uint32_t desc;
  36         uint32_t file;
  37 } __attribute__((packed));
  38
  39 struct fis_image_desc {
  40         struct fis_image_hdr hdr;
  41         char _pad[256 - sizeof(struct fis_image_hdr) - sizeof(struct fis_image_crc)];
  42         struct fis_image_crc crc;
  43 } __attribute__((packed));
  44
  45 static int fis_fd = -1;
  46 static struct fis_image_desc *fis_desc;
  47 static int fis_erasesize = 0;
  48
  49 static void
  50 fis_close(void)
  51 {
  52         if (fis_desc)
  53                 munmap(fis_desc, fis_erasesize);
  54
  55         if (fis_fd >= 0)
  56                 close(fis_fd);
  57
  58         fis_fd = -1;
  59         fis_desc = NULL;
  60 }
  61
  62 static struct fis_image_desc *
  63 fis_open(void)
  64 {
  65         struct fis_image_desc *desc;
  66
  67         if (fis_fd >= 0)
  68                 fis_close();
  69
  70         fis_fd = mtd_check_open("FIS directory");
  71         if (fis_fd < 0)
  72                 goto error;
  73
  74         close(fis_fd);
  75         fis_fd = mtd_open("FIS directory", true);
  76         if (fis_fd < 0)
  77                 goto error;
  78
  79         fis_erasesize = erasesize;
  80         desc = mmap(NULL, erasesize, PROT_READ|PROT_WRITE, MAP_SHARED, fis_fd, 0);
  81         if (desc == MAP_FAILED)
  82                 goto error;
  83
  84         fis_desc = desc;
  85         return desc;
  86
  87 error:
  88         fis_close();
  89         return NULL;
  90 }
  91
  92 int
  93 fis_validate(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
  94 {
  95         struct fis_image_desc *desc;
  96         void *end;
  97         int found = 0;
  98         int i;
  99
 100         desc = fis_open();
 101         if (!desc)
 102                 return -1;
 103
 104         for (i = 0; i < n_new - 1; i++) {
 105                 if (!new[i].size) {
 106                         fprintf(stderr, "FIS error: only the last partition can detect the size automatically\n");
 107                         i = -1;
 108                         goto done;
 109                 }
 110         }
 111
 112         end = desc;
 113         end = (char *) end + fis_erasesize;
 114         while ((void *) desc < end) {
 115                 if (!desc->hdr.name[0] || (desc->hdr.name[0] == 0xff))
 116                         break;
 117
 118                 for (i = 0; i < n_old; i++) {
 119                         if (!strncmp((char *) desc->hdr.name, (char *) old[i].name, sizeof(desc->hdr.name))) {
 120                                 found++;
 121                                 goto next;
 122                         }
 123                 }
 124 next:
 125                 desc++;
 126                 continue;
 127         }
 128
 129         if (found == n_old)
 130                 i = 1;
 131         else
 132                 i = -1;
 133
 134 done:
 135         fis_close();
 136         return i;
 137 }
 138
 139 int
 140 fis_remap(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
 141 {
 142         struct fis_image_desc *fisdir = NULL;
 143         struct fis_image_desc *redboot = NULL;
 144         struct fis_image_desc *first = NULL;
 145         struct fis_image_desc *last = NULL;
 146         struct fis_image_desc *desc;
 147         struct fis_part *part;
 148         uint32_t offset = 0, size = 0;
 149         char *start, *end, *tmp;
 150         int i;
 151
 152         desc = fis_open();
 153         if (!desc)
 154                 return -1;
 155
 156         if (!quiet)
 157                 fprintf(stderr, "Updating FIS table... \n");
 158
 159         start = (char *) desc;
 160         end = (char *) desc + fis_erasesize;
 161         while ((char *) desc < end) {
 162                 if (!desc->hdr.name[0] || (desc->hdr.name[0] == 0xff))
 163                         break;
 164
 165                 if (!strcmp((char *) desc->hdr.name, "FIS directory"))
 166                         fisdir = desc;
 167
 168                 if (!strcmp((char *) desc->hdr.name, "RedBoot"))
 169                         redboot = desc;
 170
 171                 /* update max offset */
 172                 if (offset < desc->hdr.flash_base)
 173                         offset = desc->hdr.flash_base;
 174
 175                 for (i = 0; i < n_old; i++) {
 176                         if (!strncmp((char *) desc->hdr.name, (char *) old[i].name, sizeof(desc->hdr.name))) {
 177                                 last = desc;
 178                                 if (!first)
 179                                         first = desc;
 180                                 break;
 181                         }
 182                 }
 183                 desc++;
 184         }
 185         desc--;
 186
 187         /* determine size of available space */
 188         desc = (struct fis_image_desc *) start;
 189         while ((char *) desc < end) {
 190                 if (!desc->hdr.name[0] || (desc->hdr.name[0] == 0xff))
 191                         break;
 192
 193                 if (desc->hdr.flash_base > last->hdr.flash_base &&
 194                     desc->hdr.flash_base < offset)
 195                         offset = desc->hdr.flash_base;
 196
 197                 desc++;
 198         }
 199         desc--;
 200
 201         size = offset - first->hdr.flash_base;
 202
 203 #ifdef notyet
 204         desc = first - 1;
 205         if (redboot && (desc >= redboot)) {
 206                 if (first->hdr.flash_base - desc->hdr.size > desc->hdr.flash_base) {
 207                         int delta = first->hdr.flash_base - desc->hdr.size - desc->hdr.flash_base;
 208
 209                         offset -= delta;
 210                         size += delta;
 211                 }
 212         }
 213 #endif
 214
 215         last++;
 216         desc = first + n_new;
 217         offset = first->hdr.flash_base;
 218
 219         if (desc != last) {
 220                 if (desc > last)
 221                         tmp = (char *) desc;
 222                 else
 223                         tmp = (char *) last;
 224
 225                 memmove(desc, last, end - tmp);
 226                 if (desc < last) {
 227                         tmp = end - (last - desc) * sizeof(struct fis_image_desc);
 228                         memset(tmp, 0xff, tmp - end);
 229                 }
 230         }
 231
 232         for (part = new, desc = first; desc < first + n_new; desc++, part++) {
 233                 memset(desc, 0, sizeof(struct fis_image_desc));
 234                 memcpy(desc->hdr.name, part->name, sizeof(desc->hdr.name));
 235                 desc->crc.desc = 0;
 236                 desc->crc.file = 0;
 237
 238                 desc->hdr.flash_base = offset;
 239                 desc->hdr.mem_base = part->loadaddr;
 240                 desc->hdr.entry_point = part->loadaddr;
 241                 desc->hdr.size = (part->size > 0) ? part->size : size;
 242                 desc->hdr.data_length = desc->hdr.size;
 243
 244                 offset += desc->hdr.size;
 245                 size -= desc->hdr.size;
 246         }
 247
 248         msync(fis_desc, fis_erasesize, MS_SYNC|MS_INVALIDATE);
 249         fis_close();
 250
 251         return 0;
 252 }