linux-bk/drivers/mtd/redboot.c
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   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
  16struct 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
  28struct fis_list {
  29        struct fis_image_desc *img;
  30        struct fis_list *next;
  31};
  32
  33static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
  34module_param(directory, int, 0);
  35
  36static 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
  42static 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
 214static struct mtd_part_parser redboot_parser = {
 215        .owner = THIS_MODULE,
 216        .parse_fn = parse_redboot_partitions,
 217        .name = "RedBoot",
 218};
 219
 220static int __init redboot_parser_init(void)
 221{
 222        return register_mtd_parser(&redboot_parser);
 223}
 224
 225static void __exit redboot_parser_exit(void)
 226{
 227        deregister_mtd_parser(&redboot_parser);
 228}
 229
 230module_init(redboot_parser_init);
 231module_exit(redboot_parser_exit);
 232
 233MODULE_LICENSE("GPL");
 234MODULE_AUTHOR("Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>");
 235MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");
 236
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