drivers/mtd/redboot.c

   1 /*
   2  * $Id: redboot.c,v 1.11 2003/05/21 10:39:26 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
  12 #include <linux/mtd/mtd.h>
  13 #include <linux/mtd/partitions.h>
  14
  15 struct fis_image_desc {
  16     unsigned char name[16];      // Null terminated name
  17     unsigned long flash_base;    // Address within FLASH of image
  18     unsigned long mem_base;      // Address in memory where it executes
  19     unsigned long size;          // Length of image
  20     unsigned long entry_point;   // Execution entry point
  21     unsigned long data_length;   // Length of actual data
  22     unsigned char _pad[256-(16+7*sizeof(unsigned long))];
  23     unsigned long desc_cksum;    // Checksum over image descriptor
  24     unsigned long file_cksum;    // Checksum over image data
  25 };
  26
  27 struct fis_list {
  28         struct fis_image_desc *img;
  29         struct fis_list *next;
  30 };
  31
  32 static inline int redboot_checksum(struct fis_image_desc *img)
  33 {
  34         /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
  35         return 1;
  36 }
  37
  38 static int parse_redboot_partitions(struct mtd_info *master,
  39                              struct mtd_partition **pparts,
  40                              unsigned long fis_origin)
  41 {
  42         int nrparts = 0;
  43         struct fis_image_desc *buf;
  44         struct mtd_partition *parts;
  45         struct fis_list *fl = NULL, *tmp_fl;
  46         int ret, i;
  47         size_t retlen;
  48         char *names;
  49         char *nullname;
  50         int namelen = 0;
  51         static char nullstring[] = "unallocated";
  52
  53         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
  54
  55         if (!buf)
  56                 return -ENOMEM;
  57
  58         /* Read the start of the last erase block */
  59         ret = master->read(master, master->size - master->erasesize,
  60                            PAGE_SIZE, &retlen, (void *)buf);
  61
  62         if (ret)
  63                 goto out;
  64
  65         if (retlen != PAGE_SIZE) {
  66                 ret = -EIO;
  67                 goto out;
  68         }
  69
  70         /* RedBoot image could appear in any of the first three slots */
  71         for (i = 0; i < 3; i++) {
  72                 if (!memcmp(buf[i].name, "RedBoot", 8))
  73                         break;
  74         }
  75         if (i == 3) {
  76                 /* Didn't find it */
  77                 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
  78                        master->name);
  79                 ret = 0;
  80                 goto out;
  81         }
  82
  83         for (i = 0; i < PAGE_SIZE / sizeof(struct fis_image_desc); i++) {
  84                 struct fis_list *new_fl, **prev;
  85
  86                 if (buf[i].name[0] == 0xff)
  87                         break;
  88                 if (!redboot_checksum(&buf[i]))
  89                         break;
  90
  91                 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
  92                 namelen += strlen(buf[i].name)+1;
  93                 if (!new_fl) {
  94                         ret = -ENOMEM;
  95                         goto out;
  96                 }
  97                 new_fl->img = &buf[i];
  98                 if (fis_origin) {
  99                         buf[i].flash_base -= fis_origin;
 100                 } else {
 101                         buf[i].flash_base &= master->size-1;
 102                 }
 103
 104                 /* I'm sure the JFFS2 code has done me permanent damage.
 105                  * I now think the following is _normal_
 106                  */
 107                 prev = &fl;
 108                 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
 109                         prev = &(*prev)->next;
 110                 new_fl->next = *prev;
 111                 *prev = new_fl;
 112
 113                 nrparts++;
 114         }
 115         if (fl->img->flash_base)
 116                 nrparts++;
 117
 118         for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
 119                 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize < tmp_fl->next->img->flash_base)
 120                         nrparts++;
 121         }
 122         parts = kmalloc(sizeof(*parts)*nrparts + sizeof(nullstring) + namelen, GFP_KERNEL);
 123
 124         if (!parts) {
 125                 ret = -ENOMEM;
 126                 goto out;
 127         }
 128
 129         memset(parts, 0, sizeof(*parts)*nrparts + namelen);
 130
 131         /* FIXME: Include nullname only if it's used */
 132         nullname = (char *)&parts[nrparts];
 133         sprintf(nullname, nullstring);
 134         names = nullname + sizeof(nullstring);
 135
 136         i=0;
 137
 138         if (fl->img->flash_base) {
 139                parts[0].name = nullname;
 140                parts[0].size = fl->img->flash_base;
 141                parts[0].offset = 0;
 142         }
 143         for ( ; i<nrparts; i++) {
 144                 parts[i].size = fl->img->size;
 145                 parts[i].offset = fl->img->flash_base;
 146                 parts[i].name = names;
 147
 148                 strcpy(names, fl->img->name);
 149                 names += strlen(names)+1;
 150
 151                 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize < fl->next->img->flash_base) {
 152                         i++;
 153                         parts[i].offset = parts[i-1].size + parts[i-1].offset;
 154                         parts[i].size = fl->next->img->flash_base - parts[i].offset;
 155                         parts[i].name = nullname;
 156                 }
 157                 tmp_fl = fl;
 158                 fl = fl->next;
 159                 kfree(tmp_fl);
 160         }
 161         ret = nrparts;
 162         *pparts = parts;
 163  out:
 164         while (fl) {
 165                 struct fis_list *old = fl;
 166                 fl = fl->next;
 167                 kfree(old);
 168         }
 169         kfree(buf);
 170         return ret;
 171 }
 172
 173 static struct mtd_part_parser redboot_parser = {
 174         .owner = THIS_MODULE,
 175         .parse_fn = parse_redboot_partitions,
 176         .name = "RedBoot",
 177 };
 178
 179 static int __init redboot_parser_init(void)
 180 {
 181         return register_mtd_parser(&redboot_parser);
 182 }
 183
 184 static void __exit redboot_parser_exit(void)
 185 {
 186         deregister_mtd_parser(&redboot_parser);
 187 }
 188
 189 module_init(redboot_parser_init);
 190 module_exit(redboot_parser_exit);
 191
 192 MODULE_LICENSE("GPL");
 193 MODULE_AUTHOR("Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>");
 194 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");