1 /*====================================================================== 2 3 drivers/mtd/afs.c: ARM Flash Layout/Partitioning 4 5 Copyright © 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 ======================================================================*/ 25 26 #include <linux/module.h> 27 #include <linux/types.h> 28 #include <linux/kernel.h> 29 #include <linux/slab.h> 30 #include <linux/string.h> 31 #include <linux/init.h> 32 33 #include <linux/mtd/mtd.h> 34 #include <linux/mtd/map.h> 35 #include <linux/mtd/partitions.h> 36 37 #define AFSV1_FOOTER_MAGIC 0xA0FFFF9F 38 39 struct footer_v1 { 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 47 struct image_info_v1 { 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 60 static 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 71 static int 72 afs_read_footer_v1(struct mtd_info *mtd, u_int *img_start, u_int *iis_start, 73 u_int off, u_int mask) 74 { 75 struct footer_v1 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 /* 91 * Does it contain the magic number? 92 */ 93 if (fs.signature != AFSV1_FOOTER_MAGIC) 94 return 0; 95 96 /* 97 * Check the checksum. 98 */ 99 if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff) 100 return 0; 101 102 /* 103 * Don't touch the SIB. 104 */ 105 if (fs.type == 2) 106 return 0; 107 108 *iis_start = fs.image_info_base & mask; 109 *img_start = fs.image_start & mask; 110 111 /* 112 * Check the image info base. This can not 113 * be located after the footer structure. 114 */ 115 if (*iis_start >= ptr) 116 return 0; 117 118 /* 119 * Check the start of this image. The image 120 * data can not be located after this block. 121 */ 122 if (*img_start > off) 123 return 0; 124 125 return 1; 126 } 127 128 static int 129 afs_read_iis_v1(struct mtd_info *mtd, struct image_info_v1 *iis, u_int ptr) 130 { 131 size_t sz; 132 int ret, i; 133 134 memset(iis, 0, sizeof(*iis)); 135 ret = mtd_read(mtd, ptr, sizeof(*iis), &sz, (u_char *)iis); 136 if (ret < 0) 137 goto failed; 138 139 if (sz != sizeof(*iis)) { 140 ret = -EINVAL; 141 goto failed; 142 } 143 144 ret = 0; 145 146 /* 147 * Validate the name - it must be NUL terminated. 148 */ 149 for (i = 0; i < sizeof(iis->name); i++) 150 if (iis->name[i] == '\0') 151 break; 152 153 if (i < sizeof(iis->name)) 154 ret = 1; 155 156 return ret; 157 158 failed: 159 printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", 160 ptr, ret); 161 return ret; 162 } 163 164 static int parse_afs_partitions(struct mtd_info *mtd, 165 const struct mtd_partition **pparts, 166 struct mtd_part_parser_data *data) 167 { 168 struct mtd_partition *parts; 169 u_int mask, off, idx, sz; 170 int ret = 0; 171 char *str; 172 173 /* 174 * This is the address mask; we use this to mask off out of 175 * range address bits. 176 */ 177 mask = mtd->size - 1; 178 179 /* 180 * First, calculate the size of the array we need for the 181 * partition information. We include in this the size of 182 * the strings. 183 */ 184 for (idx = off = sz = 0; off < mtd->size; off += mtd->erasesize) { 185 struct image_info_v1 iis; 186 u_int iis_ptr, img_ptr; 187 188 ret = afs_read_footer_v1(mtd, &img_ptr, &iis_ptr, off, mask); 189 if (ret < 0) 190 break; 191 if (ret) { 192 ret = afs_read_iis_v1(mtd, &iis, iis_ptr); 193 if (ret < 0) 194 break; 195 if (ret == 0) 196 continue; 197 198 sz += sizeof(struct mtd_partition); 199 sz += strlen(iis.name) + 1; 200 idx += 1; 201 } 202 } 203 204 if (!sz) 205 return ret; 206 207 parts = kzalloc(sz, GFP_KERNEL); 208 if (!parts) 209 return -ENOMEM; 210 211 str = (char *)(parts + idx); 212 213 /* 214 * Identify the partitions 215 */ 216 for (idx = off = 0; off < mtd->size; off += mtd->erasesize) { 217 struct image_info_v1 iis; 218 u_int iis_ptr, img_ptr; 219 220 /* Read the footer. */ 221 ret = afs_read_footer_v1(mtd, &img_ptr, &iis_ptr, off, mask); 222 if (ret < 0) 223 break; 224 if (ret == 0) 225 continue; 226 227 /* Read the image info block */ 228 ret = afs_read_iis_v1(mtd, &iis, iis_ptr); 229 if (ret < 0) 230 break; 231 if (ret == 0) 232 continue; 233 234 strcpy(str, iis.name); 235 236 parts[idx].name = str; 237 parts[idx].size = (iis.length + mtd->erasesize - 1) & ~(mtd->erasesize - 1); 238 parts[idx].offset = img_ptr; 239 parts[idx].mask_flags = 0; 240 241 printk(" mtd%d: at 0x%08x, %5lluKiB, %8u, %s\n", 242 idx, img_ptr, parts[idx].size / 1024, 243 iis.imageNumber, str); 244 245 idx += 1; 246 str = str + strlen(iis.name) + 1; 247 } 248 249 if (!idx) { 250 kfree(parts); 251 parts = NULL; 252 } 253 254 *pparts = parts; 255 return idx ? idx : ret; 256 } 257 258 static const struct of_device_id mtd_parser_afs_of_match_table[] = { 259 { .compatible = "arm,arm-firmware-suite" }, 260 {}, 261 }; 262 MODULE_DEVICE_TABLE(of, mtd_parser_afs_of_match_table); 263 264 static struct mtd_part_parser afs_parser = { 265 .parse_fn = parse_afs_partitions, 266 .name = "afs", 267 .of_match_table = mtd_parser_afs_of_match_table, 268 }; 269 module_mtd_part_parser(afs_parser); 270 271 MODULE_AUTHOR("ARM Ltd"); 272 MODULE_DESCRIPTION("ARM Firmware Suite partition parser"); 273 MODULE_LICENSE("GPL"); 274