drivers/mtd/redboot.c

   1 /*
   2  * $Id: redboot.c,v 1.15 2004/08/10 07:55:16 dwmw2 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 inline int redboot_checksum(struct fis_image_desc *img)
  34 {
  35         /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
  36         return 1;
  37 }
  38
  39 static int parse_redboot_partitions(struct mtd_info *master,
  40                              struct mtd_partition **pparts,
  41                              unsigned long fis_origin)
  42 {
  43         int nrparts = 0;
  44         struct fis_image_desc *buf;
  45         struct mtd_partition *parts;
  46         struct fis_list *fl = NULL, *tmp_fl;
  47         int ret, i;
  48         size_t retlen;
  49         char *names;
  50         char *nullname;
  51         int namelen = 0;
  52         int nulllen = 0;
  53 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
  54         static char nullstring[] = "unallocated";
  55 #endif
  56
  57         buf = vmalloc(master->erasesize);
  58
  59         if (!buf)
  60                 return -ENOMEM;
  61
  62         /* Read the start of the last erase block */
  63         ret = master->read(master, master->size - master->erasesize,
  64                            master->erasesize, &retlen, (void *)buf);
  65
  66         if (ret)
  67                 goto out;
  68
  69         if (retlen != master->erasesize) {
  70                 ret = -EIO;
  71                 goto out;
  72         }
  73
  74         /* RedBoot image could appear in any of the first three slots */
  75         for (i = 0; i < 3; i++) {
  76                 if (!memcmp(buf[i].name, "RedBoot", 8))
  77                         break;
  78         }
  79         if (i == 3) {
  80                 /* Didn't find it */
  81                 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
  82                        master->name);
  83                 ret = 0;
  84                 goto out;
  85         }
  86
  87         for (i = 0; i < master->erasesize / sizeof(struct fis_image_desc); i++) {
  88                 struct fis_list *new_fl, **prev;
  89
  90                 if (buf[i].name[0] == 0xff)
  91                         break;
  92                 if (!redboot_checksum(&buf[i]))
  93                         break;
  94
  95                 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
  96                 namelen += strlen(buf[i].name)+1;
  97                 if (!new_fl) {
  98                         ret = -ENOMEM;
  99                         goto out;
 100                 }
 101                 new_fl->img = &buf[i];
 102                 if (fis_origin) {
 103                         buf[i].flash_base -= fis_origin;
 104                 } else {
 105                         buf[i].flash_base &= master->size-1;
 106                 }
 107
 108                 /* I'm sure the JFFS2 code has done me permanent damage.
 109                  * I now think the following is _normal_
 110                  */
 111                 prev = &fl;
 112                 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
 113                         prev = &(*prev)->next;
 114                 new_fl->next = *prev;
 115                 *prev = new_fl;
 116
 117                 nrparts++;
 118         }
 119 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 120         if (fl->img->flash_base) {
 121                 nrparts++;
 122                 nulllen = sizeof(nullstring);
 123         }
 124
 125         for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
 126                 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
 127                         nrparts++;
 128                         nulllen = sizeof(nullstring);
 129                 }
 130         }
 131 #endif
 132         parts = kmalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
 133
 134         if (!parts) {
 135                 ret = -ENOMEM;
 136                 goto out;
 137         }
 138
 139         memset(parts, 0, sizeof(*parts)*nrparts + nulllen + namelen);
 140
 141         nullname = (char *)&parts[nrparts];
 142 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 143         if (nulllen > 0) {
 144                 strcpy(nullname, nullstring);
 145         }
 146 #endif
 147         names = nullname + nulllen;
 148
 149         i=0;
 150
 151 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 152         if (fl->img->flash_base) {
 153                parts[0].name = nullname;
 154                parts[0].size = fl->img->flash_base;
 155                parts[0].offset = 0;
 156                 i++;
 157         }
 158 #endif
 159         for ( ; i<nrparts; i++) {
 160                 parts[i].size = fl->img->size;
 161                 parts[i].offset = fl->img->flash_base;
 162                 parts[i].name = names;
 163
 164                 strcpy(names, fl->img->name);
 165 #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
 166                 if (!memcmp(names, "RedBoot", 8) ||
 167                                 !memcmp(names, "RedBoot config", 15) ||
 168                                 !memcmp(names, "FIS directory", 14)) {
 169                         parts[i].mask_flags = MTD_WRITEABLE;
 170                 }
 171 #endif
 172                 names += strlen(names)+1;
 173
 174 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
 175                 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
 176                         i++;
 177                         parts[i].offset = parts[i-1].size + parts[i-1].offset;
 178                         parts[i].size = fl->next->img->flash_base - parts[i].offset;
 179                         parts[i].name = nullname;
 180                 }
 181 #endif
 182                 tmp_fl = fl;
 183                 fl = fl->next;
 184                 kfree(tmp_fl);
 185         }
 186         ret = nrparts;
 187         *pparts = parts;
 188  out:
 189         while (fl) {
 190                 struct fis_list *old = fl;
 191                 fl = fl->next;
 192                 kfree(old);
 193         }
 194         vfree(buf);
 195         return ret;
 196 }
 197
 198 static struct mtd_part_parser redboot_parser = {
 199         .owner = THIS_MODULE,
 200         .parse_fn = parse_redboot_partitions,
 201         .name = "RedBoot",
 202 };
 203
 204 static int __init redboot_parser_init(void)
 205 {
 206         return register_mtd_parser(&redboot_parser);
 207 }
 208
 209 static void __exit redboot_parser_exit(void)
 210 {
 211         deregister_mtd_parser(&redboot_parser);
 212 }
 213
 214 module_init(redboot_parser_init);
 215 module_exit(redboot_parser_exit);
 216
 217 MODULE_LICENSE("GPL");
 218 MODULE_AUTHOR("Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>");
 219 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");