1/*====================================================================== 2 3 drivers/mtd/afs.c: ARM Flash Layout/Partitioning 4 5 Copyright (C) 2000 ARM Limited 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 21 This is access code for flashes using ARM's flash partitioning 22 standards. 23 24 $Id: afs.c,v 1.1.1.1 2007/08/03 18:52:43 Exp $ 25 26======================================================================*/ 27 28#include <linux/module.h> 29#include <linux/types.h> 30#include <linux/kernel.h> 31#include <linux/slab.h> 32#include <linux/string.h> 33#include <linux/init.h> 34 35#include <linux/mtd/mtd.h> 36#include <linux/mtd/map.h> 37#include <linux/mtd/partitions.h> 38 39struct footer_struct { 40 u32 image_info_base; /* Address of first word of ImageFooter */ 41 u32 image_start; /* Start of area reserved by this footer */ 42 u32 signature; /* 'Magic' number proves it's a footer */ 43 u32 type; /* Area type: ARM Image, SIB, customer */ 44 u32 checksum; /* Just this structure */ 45}; 46 47struct image_info_struct { 48 u32 bootFlags; /* Boot flags, compression etc. */ 49 u32 imageNumber; /* Unique number, selects for boot etc. */ 50 u32 loadAddress; /* Address program should be loaded to */ 51 u32 length; /* Actual size of image */ 52 u32 address; /* Image is executed from here */ 53 char name[16]; /* Null terminated */ 54 u32 headerBase; /* Flash Address of any stripped header */ 55 u32 header_length; /* Length of header in memory */ 56 u32 headerType; /* AIF, RLF, s-record etc. */ 57 u32 checksum; /* Image checksum (inc. this struct) */ 58}; 59 60static u32 word_sum(void *words, int num) 61{ 62 u32 *p = words; 63 u32 sum = 0; 64 65 while (num--) 66 sum += *p++; 67 68 return sum; 69} 70 71static int 72afs_read_footer(struct mtd_info *mtd, u_int *img_start, u_int *iis_start, 73 u_int off, u_int mask) 74{ 75 struct footer_struct fs; 76 u_int ptr = off + mtd->erasesize - sizeof(fs); 77 size_t sz; 78 int ret; 79 80 ret = mtd->read(mtd, ptr, sizeof(fs), &sz, (u_char *) &fs); 81 if (ret >= 0 && sz != sizeof(fs)) 82 ret = -EINVAL; 83 84 if (ret < 0) { 85 printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", 86 ptr, ret); 87 return ret; 88 } 89 90 ret = 1; 91 92 /* 93 * Does it contain the magic number? 94 */ 95 if (fs.signature != 0xa0ffff9f) 96 ret = 0; 97 98 /* 99 * Check the checksum. 100 */ 101 if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff) 102 ret = 0; 103 104 /* 105 * Don't touch the SIB. 106 */ 107 if (fs.type == 2) 108 ret = 0; 109 110 *iis_start = fs.image_info_base & mask; 111 *img_start = fs.image_start & mask; 112 113 /* 114 * Check the image info base. This can not 115 * be located after the footer structure. 116 */ 117 if (*iis_start >= ptr) 118 ret = 0; 119 120 /* 121 * Check the start of this image. The image 122 * data can not be located after this block. 123 */ 124 if (*img_start > off) 125 ret = 0; 126 127 return ret; 128} 129 130static int 131afs_read_iis(struct mtd_info *mtd, struct image_info_struct *iis, u_int ptr) 132{ 133 size_t sz; 134 int ret, i; 135 136 memset(iis, 0, sizeof(*iis)); 137 ret = mtd->read(mtd, ptr, sizeof(*iis), &sz, (u_char *) iis); 138 if (ret < 0) 139 goto failed; 140 141 if (sz != sizeof(*iis)) { 142 ret = -EINVAL; 143 goto failed; 144 } 145 146 ret = 0; 147 148 /* 149 * Validate the name - it must be NUL terminated. 150 */ 151 for (i = 0; i < sizeof(iis->name); i++) 152 if (iis->name[i] == '\0') 153 break; 154 155 if (i < sizeof(iis->name)) 156 ret = 1; 157 158 return ret; 159 160 failed: 161 printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", 162 ptr, ret); 163 return ret; 164} 165 166static int parse_afs_partitions(struct mtd_info *mtd, 167 struct mtd_partition **pparts, 168 unsigned long origin) 169{ 170 struct mtd_partition *parts; 171 u_int mask, off, idx, sz; 172 int ret = 0; 173 char *str; 174 175 /* 176 * This is the address mask; we use this to mask off out of 177 * range address bits. 178 */ 179 mask = mtd->size - 1; 180 181 /* 182 * First, calculate the size of the array we need for the 183 * partition information. We include in this the size of 184 * the strings. 185 */ 186 for (idx = off = sz = 0; off < mtd->size; off += mtd->erasesize) { 187 struct image_info_struct iis; 188 u_int iis_ptr, img_ptr; 189 190 ret = afs_read_footer(mtd, &img_ptr, &iis_ptr, off, mask); 191 if (ret < 0) 192 break; 193 if (ret == 0) 194 continue; 195 196 ret = afs_read_iis(mtd, &iis, iis_ptr); 197 if (ret < 0) 198 break; 199 if (ret == 0) 200 continue; 201 202 sz += sizeof(struct mtd_partition); 203 sz += strlen(iis.name) + 1; 204 idx += 1; 205 } 206 207 if (!sz) 208 return ret; 209 210 parts = kzalloc(sz, GFP_KERNEL); 211 if (!parts) 212 return -ENOMEM; 213 214 str = (char *)(parts + idx); 215 216 /* 217 * Identify the partitions 218 */ 219 for (idx = off = 0; off < mtd->size; off += mtd->erasesize) { 220 struct image_info_struct iis; 221 u_int iis_ptr, img_ptr; 222 223 /* Read the footer. */ 224 ret = afs_read_footer(mtd, &img_ptr, &iis_ptr, off, mask); 225 if (ret < 0) 226 break; 227 if (ret == 0) 228 continue; 229 230 /* Read the image info block */ 231 ret = afs_read_iis(mtd, &iis, iis_ptr); 232 if (ret < 0) 233 break; 234 if (ret == 0) 235 continue; 236 237 strcpy(str, iis.name); 238 239 parts[idx].name = str; 240 parts[idx].size = (iis.length + mtd->erasesize - 1) & ~(mtd->erasesize - 1); 241 parts[idx].offset = img_ptr; 242 parts[idx].mask_flags = 0; 243 244 printk(" mtd%d: at 0x%08x, %5dKB, %8u, %s\n", 245 idx, img_ptr, parts[idx].size / 1024, 246 iis.imageNumber, str); 247 248 idx += 1; 249 str = str + strlen(iis.name) + 1; 250 } 251 252 if (!idx) { 253 kfree(parts); 254 parts = NULL; 255 } 256 257 *pparts = parts; 258 return idx ? idx : ret; 259} 260 261static struct mtd_part_parser afs_parser = { 262 .owner = THIS_MODULE, 263 .parse_fn = parse_afs_partitions, 264 .name = "afs", 265}; 266 267static int __init afs_parser_init(void) 268{ 269 return register_mtd_parser(&afs_parser); 270} 271 272static void __exit afs_parser_exit(void) 273{ 274 deregister_mtd_parser(&afs_parser); 275} 276 277module_init(afs_parser_init); 278module_exit(afs_parser_exit); 279 280 281MODULE_AUTHOR("ARM Ltd"); 282MODULE_DESCRIPTION("ARM Firmware Suite partition parser"); 283MODULE_LICENSE("GPL"); 284