target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_bcm_wfi.c

   1 /*
   2  * MTD split for Broadcom Whole Flash Image
   3  *
   4  * Copyright (C) 2020 Álvaro Fernández Rojas <noltari@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published
   8  * by the Free Software Foundation.
   9  *
  10  */
  11
  12 #define je16_to_cpu(x) ((x).v16)
  13 #define je32_to_cpu(x) ((x).v32)
  14
  15 #include <linux/crc32.h>
  16 #include <linux/init.h>
  17 #include <linux/jffs2.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/slab.h>
  21 #include <linux/byteorder/generic.h>
  22 #include <linux/mtd/mtd.h>
  23 #include <linux/mtd/partitions.h>
  24
  25 #include "mtdsplit.h"
  26
  27 #define char_to_num(c)          ((c >= '0' && c <= '9') ? (c - '0') : (0))
  28
  29 #define BCM_WFI_PARTS           3
  30
  31 #define CFERAM_NAME             "cferam"
  32 #define CFERAM_NAME_LEN         (sizeof(CFERAM_NAME) - 1)
  33 #define KERNEL_NAME             "vmlinux.lz"
  34 #define KERNEL_NAME_LEN         (sizeof(KERNEL_NAME) - 1)
  35 #define OPENWRT_NAME            "1-openwrt"
  36 #define OPENWRT_NAME_LEN        (sizeof(OPENWRT_NAME) - 1)
  37
  38 #define UBI_MAGIC               0x55424923
  39
  40 #define SERCOMM_MAGIC_PFX       "eRcOmM."
  41 #define SERCOMM_MAGIC_PFX_LEN   (sizeof(SERCOMM_MAGIC_PFX) - 1)
  42 #define SERCOMM_MAGIC           "eRcOmM.000"
  43 #define SERCOMM_MAGIC_LEN       (sizeof(SERCOMM_MAGIC) - 1)
  44
  45 static u32 jffs2_dirent_crc(struct jffs2_raw_dirent *node)
  46 {
  47         return crc32(0, node, sizeof(struct jffs2_raw_dirent) - 8);
  48 }
  49
  50 static bool jffs2_dirent_valid(struct jffs2_raw_dirent *node)
  51 {
  52         return ((je16_to_cpu(node->magic) == JFFS2_MAGIC_BITMASK) &&
  53                 (je16_to_cpu(node->nodetype) == JFFS2_NODETYPE_DIRENT) &&
  54                 je32_to_cpu(node->ino) &&
  55                 je32_to_cpu(node->node_crc) == jffs2_dirent_crc(node));
  56 }
  57
  58 static int jffs2_find_file(struct mtd_info *mtd, uint8_t *buf,
  59                            const char *name, size_t name_len,
  60                            loff_t *offs, loff_t size)
  61 {
  62         const loff_t end = *offs + size;
  63         struct jffs2_raw_dirent *node;
  64         bool valid = false;
  65         size_t retlen;
  66         uint16_t magic;
  67         int rc;
  68
  69         for (; *offs < end; *offs += mtd->erasesize) {
  70                 unsigned int block_offs = 0;
  71
  72                 /* Skip CFE erased blocks */
  73                 rc = mtd_read(mtd, *offs, sizeof(magic), &retlen,
  74                               (void *) &magic);
  75                 if (rc || retlen != sizeof(magic)) {
  76                         continue;
  77                 }
  78
  79                 /* Skip blocks not starting with JFFS2 magic */
  80                 if (magic != JFFS2_MAGIC_BITMASK)
  81                         continue;
  82
  83                 /* Read full block */
  84                 rc = mtd_read(mtd, *offs, mtd->erasesize, &retlen,
  85                               (void *) buf);
  86                 if (rc)
  87                         return rc;
  88                 if (retlen != mtd->erasesize)
  89                         return -EINVAL;
  90
  91                 while (block_offs < mtd->erasesize) {
  92                         node = (struct jffs2_raw_dirent *) &buf[block_offs];
  93
  94                         if (!jffs2_dirent_valid(node)) {
  95                                 block_offs += 4;
  96                                 continue;
  97                         }
  98
  99                         if (!memcmp(node->name, OPENWRT_NAME,
 100                                     OPENWRT_NAME_LEN))
 101                                 valid = true;
 102                         else if (!memcmp(node->name, name, name_len))
 103                                 return valid ? 0 : -EINVAL;
 104
 105                         block_offs += je32_to_cpu(node->totlen);
 106                         block_offs = (block_offs + 0x3) & ~0x3;
 107                 }
 108         }
 109
 110         return -ENOENT;
 111 }
 112
 113 static int ubifs_find(struct mtd_info *mtd, loff_t *offs, loff_t size)
 114 {
 115         const loff_t end = *offs + size;
 116         uint32_t magic;
 117         size_t retlen;
 118         int rc;
 119
 120         for (; *offs < end; *offs += mtd->erasesize) {
 121                 rc = mtd_read(mtd, *offs, sizeof(magic), &retlen,
 122                               (unsigned char *) &magic);
 123                 if (rc || retlen != sizeof(magic))
 124                         continue;
 125
 126                 if (be32_to_cpu(magic) == UBI_MAGIC)
 127                         return 0;
 128         }
 129
 130         return -ENOENT;
 131 }
 132
 133 static int parse_bcm_wfi(struct mtd_info *master,
 134                          const struct mtd_partition **pparts,
 135                          uint8_t *buf, loff_t off, loff_t size, bool cfe_part)
 136 {
 137         struct mtd_partition *parts;
 138         loff_t cfe_off, kernel_off, rootfs_off;
 139         unsigned int num_parts = BCM_WFI_PARTS, cur_part = 0;
 140         int ret;
 141
 142         if (cfe_part) {
 143                 num_parts++;
 144                 cfe_off = off;
 145
 146                 ret = jffs2_find_file(master, buf, CFERAM_NAME,
 147                                       CFERAM_NAME_LEN, &cfe_off,
 148                                       size - (cfe_off - off));
 149                 if (ret)
 150                         return ret;
 151
 152                 kernel_off = cfe_off + master->erasesize;
 153         } else {
 154                 kernel_off = off;
 155         }
 156
 157         ret = jffs2_find_file(master, buf, KERNEL_NAME, KERNEL_NAME_LEN,
 158                               &kernel_off, size - (kernel_off - off));
 159         if (ret)
 160                 return ret;
 161
 162         rootfs_off = kernel_off + master->erasesize;
 163         ret = ubifs_find(master, &rootfs_off, size - (rootfs_off - off));
 164         if (ret)
 165                 return ret;
 166
 167         parts = kzalloc(num_parts * sizeof(*parts), GFP_KERNEL);
 168         if (!parts)
 169                 return -ENOMEM;
 170
 171         if (cfe_part) {
 172                 parts[cur_part].name = "cferam";
 173                 parts[cur_part].mask_flags = MTD_WRITEABLE;
 174                 parts[cur_part].offset = cfe_off;
 175                 parts[cur_part].size = kernel_off - cfe_off;
 176                 cur_part++;
 177         }
 178
 179         parts[cur_part].name = "firmware";
 180         parts[cur_part].offset = kernel_off;
 181         parts[cur_part].size = size - (kernel_off - off);
 182         cur_part++;
 183
 184         parts[cur_part].name = KERNEL_PART_NAME;
 185         parts[cur_part].offset = kernel_off;
 186         parts[cur_part].size = rootfs_off - kernel_off;
 187         cur_part++;
 188
 189         parts[cur_part].name = UBI_PART_NAME;
 190         parts[cur_part].offset = rootfs_off;
 191         parts[cur_part].size = size - (rootfs_off - off);
 192         cur_part++;
 193
 194         *pparts = parts;
 195
 196         return num_parts;
 197 }
 198
 199 static int mtdsplit_parse_bcm_wfi(struct mtd_info *master,
 200                                   const struct mtd_partition **pparts,
 201                                   struct mtd_part_parser_data *data)
 202 {
 203         struct device_node *mtd_node;
 204         bool cfe_part = true;
 205         uint8_t *buf;
 206         int ret;
 207
 208         mtd_node = mtd_get_of_node(master);
 209         if (!mtd_node)
 210                 return -EINVAL;
 211
 212         buf = kzalloc(master->erasesize, GFP_KERNEL);
 213         if (!buf)
 214                 return -ENOMEM;
 215
 216         if (of_property_read_bool(mtd_node, "brcm,no-cferam"))
 217                 cfe_part = false;
 218
 219         ret = parse_bcm_wfi(master, pparts, buf, 0, master->size, cfe_part);
 220
 221         kfree(buf);
 222
 223         return ret;
 224 }
 225
 226 static const struct of_device_id mtdsplit_bcm_wfi_of_match[] = {
 227         { .compatible = "brcm,wfi" },
 228         { },
 229 };
 230
 231 static struct mtd_part_parser mtdsplit_bcm_wfi_parser = {
 232         .owner = THIS_MODULE,
 233         .name = "bcm-wfi-fw",
 234         .of_match_table = mtdsplit_bcm_wfi_of_match,
 235         .parse_fn = mtdsplit_parse_bcm_wfi,
 236         .type = MTD_PARSER_TYPE_FIRMWARE,
 237 };
 238
 239 static int sercomm_bootflag_value(struct mtd_info *mtd, uint8_t *buf)
 240 {
 241         size_t retlen;
 242         loff_t offs;
 243         int rc;
 244
 245         for (offs = 0; offs < mtd->size; offs += mtd->erasesize) {
 246                 rc = mtd_read(mtd, offs, SERCOMM_MAGIC_LEN, &retlen, buf);
 247                 if (rc || retlen != SERCOMM_MAGIC_LEN)
 248                         continue;
 249
 250                 if (memcmp(buf, SERCOMM_MAGIC_PFX, SERCOMM_MAGIC_PFX_LEN))
 251                         continue;
 252
 253                 rc = char_to_num(buf[SERCOMM_MAGIC_PFX_LEN + 0]) * 100;
 254                 rc += char_to_num(buf[SERCOMM_MAGIC_PFX_LEN + 1]) * 10;
 255                 rc += char_to_num(buf[SERCOMM_MAGIC_PFX_LEN + 2]) * 1;
 256
 257                 return rc;
 258         }
 259
 260         return -ENOENT;
 261 }
 262
 263 static int mtdsplit_parse_ser_wfi(struct mtd_info *master,
 264                                   const struct mtd_partition **pparts,
 265                                   struct mtd_part_parser_data *data)
 266 {
 267         struct mtd_info *mtd_bf1, *mtd_bf2;
 268         struct erase_info bf_erase;
 269         loff_t img1_off = 0;
 270         loff_t img2_off = master->size / 2;
 271         loff_t img1_size = (img2_off - img1_off);
 272         loff_t img2_size = (master->size - img2_off);
 273         loff_t active_off, inactive_off;
 274         loff_t active_size, inactive_size;
 275         uint8_t *buf;
 276         int bf1, bf2;
 277         int ret;
 278
 279         mtd_bf1 = get_mtd_device_nm("bootflag1");
 280         if (IS_ERR(mtd_bf1))
 281                 return -ENOENT;
 282
 283         mtd_bf2 = get_mtd_device_nm("bootflag2");
 284         if (IS_ERR(mtd_bf2))
 285                 return -ENOENT;
 286
 287         buf = kzalloc(master->erasesize, GFP_KERNEL);
 288         if (!buf)
 289                 return -ENOMEM;
 290
 291         bf1 = sercomm_bootflag_value(mtd_bf1, buf);
 292         if (bf1 >= 0)
 293                 printk("sercomm: bootflag1=%d\n", bf1);
 294
 295         bf2 = sercomm_bootflag_value(mtd_bf2, buf);
 296         if (bf2 >= 0)
 297                 printk("sercomm: bootflag2=%d\n", bf2);
 298
 299         if (bf1 == bf2 && bf2 >= 0) {
 300                 bf2 = -ENOENT;
 301                 bf_erase.addr = 0;
 302                 bf_erase.len = mtd_bf2->size;
 303                 mtd_erase(mtd_bf2, &bf_erase);
 304         }
 305
 306         if (bf1 >= bf2) {
 307                 active_off = img1_off;
 308                 active_size = img1_size;
 309                 inactive_off = img2_off;
 310                 inactive_size = img2_size;
 311         } else {
 312                 active_off = img2_off;
 313                 active_size = img2_size;
 314                 inactive_off = img1_off;
 315                 inactive_size = img1_size;
 316         }
 317
 318         ret = parse_bcm_wfi(master, pparts, buf, active_off, active_size, false);
 319
 320         kfree(buf);
 321
 322         if (ret > 0) {
 323                 struct mtd_partition *parts;
 324
 325                 parts = kzalloc((ret + 1) * sizeof(*parts), GFP_KERNEL);
 326                 if (!parts)
 327                         return -ENOMEM;
 328
 329                 memcpy(parts, *pparts, ret * sizeof(*parts));
 330                 kfree(*pparts);
 331
 332                 parts[ret].name = "img2";
 333                 parts[ret].offset = inactive_off;
 334                 parts[ret].size = inactive_size;
 335                 ret++;
 336
 337                 *pparts = parts;
 338         }
 339
 340         return ret;
 341 }
 342
 343 static const struct of_device_id mtdsplit_ser_wfi_of_match[] = {
 344         { .compatible = "sercomm,wfi" },
 345         { },
 346 };
 347
 348 static struct mtd_part_parser mtdsplit_ser_wfi_parser = {
 349         .owner = THIS_MODULE,
 350         .name = "ser-wfi-fw",
 351         .of_match_table = mtdsplit_ser_wfi_of_match,
 352         .parse_fn = mtdsplit_parse_ser_wfi,
 353         .type = MTD_PARSER_TYPE_FIRMWARE,
 354 };
 355
 356 static int __init mtdsplit_bcm_wfi_init(void)
 357 {
 358         register_mtd_parser(&mtdsplit_bcm_wfi_parser);
 359         register_mtd_parser(&mtdsplit_ser_wfi_parser);
 360
 361         return 0;
 362 }
 363
 364 module_init(mtdsplit_bcm_wfi_init);