drivers/mtd/redboot.c

   1 /*
   2  * $Id: redboot.c,v 1.17 2004/11/22 11:33:56 ijc Exp $
   3  *
   4  * Parse RedBoot-style Flash Image System (FIS) tables and
   5  * produce a Linux partition array to match.
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/slab.h>
  10 #include <linux/init.h>
  11 #include <linux/vmalloc.h>
  12
  13 #include <linux/mtd/mtd.h>
  14 #include <linux/mtd/partitions.h>
  15
  16 struct fis_image_desc {
  17     unsigned char name[16];      // Null terminated name
  18     unsigned long flash_base;    // Address within FLASH of image
  19     unsigned long mem_base;      // Address in memory where it executes
  20     unsigned long size;          // Length of image
  21     unsigned long entry_point;   // Execution entry point
  22     unsigned long data_length;   // Length of actual data
  23     unsigned char _pad[256-(16+7*sizeof(unsigned long))];
  24     unsigned long desc_cksum;    // Checksum over image descriptor
  25     unsigned long file_cksum;    // Checksum over image data
  26 };
  27
  28 struct fis_list {
  29         struct fis_image_desc *img;
  30         struct fis_list *next;
  31 };
  32
  33 static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
  34 module_param(directory, int, 0);
  35
  36 static inline int redboot_checksum(struct fis_image_desc *img)
  37 {
  38         /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
  39         return 1;
  40 }
  41
  42 static int parse_redboot_partitions(struct mtd_info *master,
  43                              struct mtd_partition **pparts,
  44                              unsigned long fis_origin)
  45 {
  46         int nrparts = 0;
  47         struct fis_image_desc *buf;
  48         struct mtd_partition *parts;
  49         struct fis_list *fl = NULL, *tmp_fl;
  50         int ret, i;
  51         size_t retlen;
  52         char *names;
  53         char *nullname;
  54         int namelen = 0;
  55         int nulllen = 0;
  56         int numslots;
  57         unsigned long offset;
  58 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
  59         static char nullstring[] = "unallocated";
  60 #endif
  61
  62         buf = vmalloc(master->erasesize);
  63
  64         if (!buf)
  65                 return -ENOMEM;
  66
  67         if ( directory < 0 )
  68                 offset = master->size + directory*master->erasesize;
  69         else
  70                 offset = directory*master->erasesize;
  71
  72         printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
  73                master->name, offset);
  74
  75         ret = master->read(master, offset,
  76                            master->erasesize, &retlen, (void *)buf);
  77
  78         if (ret)
  79                 goto out;
  80
  81         if (retlen != master->erasesize) {
  82                 ret = -EIO;
  83                 goto out;
  84         }
  85
  86         numslots = (master->erasesize / sizeof(struct fis_image_desc));
  87         for (i = 0; i < numslots; i++) {
  88                 if (buf[i].name[0] == 0xff) {
  89                         i = numslots;
  90                         break;
  91                 }
  92                 if (!memcmp(buf[i].name, "FIS directory", 14))
  93                         break;
  94         }
  95         if (i == numslots) {
  96                 /* Didn't find it */
  97                 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
  98                        master->name);
  99                 ret = 0;
 100                 goto out;
 101         }
 102
 103         for (i = 0; i < numslots; i++) {
 104                 struct fis_list *new_fl, **prev;
 105
 106                 if (buf[i].name[0] == 0xff)
 107                         break;
 108                 if (!redboot_checksum(&buf[i]))
 109                         break;
 110
 111                 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
 112                 namelen += strlen(buf[i].name)+1;
 113                 if (!new_fl) {
 114                         ret = -ENOMEM;
 115                         goto out;
 116                 }
 117                 new_fl->img = &buf[i];
 118                 if (fis_origin) {
 119                         buf[i].flash_base -= fis_origin;
 120                 } else {
 121                         buf[i].flash_base &= master->size-1;
 122                 }
 123
 124                 /* I'm sure the JFFS2 code has done me permanent damage.
 125                  * I now think the following is _normal_
 126                  */
 127                 prev = &fl;
 128                 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
 129                         prev = &(*prev)->next;
 130                 new_fl->next = *prev;
 131                 *prev = new_fl;
 132
 133                 nrparts++;
 134         }
 135 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 136         if (fl->img->flash_base) {
 137                 nrparts++;
 138                 nulllen = sizeof(nullstring);
 139         }
 140
 141         for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
 142                 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
 143                         nrparts++;
 144                         nulllen = sizeof(nullstring);
 145                 }
 146         }
 147 #endif
 148         parts = kmalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
 149
 150         if (!parts) {
 151                 ret = -ENOMEM;
 152                 goto out;
 153         }
 154
 155         memset(parts, 0, sizeof(*parts)*nrparts + nulllen + namelen);
 156
 157         nullname = (char *)&parts[nrparts];
 158 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 159         if (nulllen > 0) {
 160                 strcpy(nullname, nullstring);
 161         }
 162 #endif
 163         names = nullname + nulllen;
 164
 165         i=0;
 166
 167 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 168         if (fl->img->flash_base) {
 169                parts[0].name = nullname;
 170                parts[0].size = fl->img->flash_base;
 171                parts[0].offset = 0;
 172                 i++;
 173         }
 174 #endif
 175         for ( ; i<nrparts; i++) {
 176                 parts[i].size = fl->img->size;
 177                 parts[i].offset = fl->img->flash_base;
 178                 parts[i].name = names;
 179
 180                 strcpy(names, fl->img->name);
 181 #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
 182                 if (!memcmp(names, "RedBoot", 8) ||
 183                                 !memcmp(names, "RedBoot config", 15) ||
 184                                 !memcmp(names, "FIS directory", 14)) {
 185                         parts[i].mask_flags = MTD_WRITEABLE;
 186                 }
 187 #endif
 188                 names += strlen(names)+1;
 189
 190 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 191                 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
 192                         i++;
 193                         parts[i].offset = parts[i-1].size + parts[i-1].offset;
 194                         parts[i].size = fl->next->img->flash_base - parts[i].offset;
 195                         parts[i].name = nullname;
 196                 }
 197 #endif
 198                 tmp_fl = fl;
 199                 fl = fl->next;
 200                 kfree(tmp_fl);
 201         }
 202         ret = nrparts;
 203         *pparts = parts;
 204  out:
 205         while (fl) {
 206                 struct fis_list *old = fl;
 207                 fl = fl->next;
 208                 kfree(old);
 209         }
 210         vfree(buf);
 211         return ret;
 212 }
 213
 214 static struct mtd_part_parser redboot_parser = {
 215         .owner = THIS_MODULE,
 216         .parse_fn = parse_redboot_partitions,
 217         .name = "RedBoot",
 218 };
 219
 220 static int __init redboot_parser_init(void)
 221 {
 222         return register_mtd_parser(&redboot_parser);
 223 }
 224
 225 static void __exit redboot_parser_exit(void)
 226 {
 227         deregister_mtd_parser(&redboot_parser);
 228 }
 229
 230 module_init(redboot_parser_init);
 231 module_exit(redboot_parser_exit);
 232
 233 MODULE_LICENSE("GPL");
 234 MODULE_AUTHOR("Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>");
 235 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");