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3cf7f131 RM |
1 | /* |
2 | * BCM47XX MTD partitioning | |
3 | * | |
4 | * Copyright © 2012 Rafał Miłecki <zajec5@gmail.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/mtd/mtd.h> | |
16 | #include <linux/mtd/partitions.h> | |
3cf7f131 | 17 | |
0b56d2d4 RM |
18 | #include <uapi/linux/magic.h> |
19 | ||
59af5c7a RM |
20 | /* |
21 | * NAND flash on Netgear R6250 was verified to contain 15 partitions. | |
22 | * This will result in allocating too big array for some old devices, but the | |
23 | * memory will be freed soon anyway (see mtd_device_parse_register). | |
24 | */ | |
25 | #define BCM47XXPART_MAX_PARTS 20 | |
3cf7f131 | 26 | |
5ca1088f RM |
27 | /* |
28 | * Amount of bytes we read when analyzing each block of flash memory. | |
29 | * Set it big enough to allow detecting partition and reading important data. | |
30 | */ | |
4f8aaf72 | 31 | #define BCM47XXPART_BYTES_TO_READ 0x4e8 |
5ca1088f | 32 | |
3cf7f131 RM |
33 | /* Magics */ |
34 | #define BOARD_DATA_MAGIC 0x5246504D /* MPFR */ | |
f0501e81 | 35 | #define BOARD_DATA_MAGIC2 0xBD0D0BBD |
4f8aaf72 | 36 | #define CFE_MAGIC 0x43464531 /* 1EFC */ |
33094c73 | 37 | #define FACTORY_MAGIC 0x59544346 /* FCTY */ |
9e3afa5f | 38 | #define NVRAM_HEADER 0x48534C46 /* FLSH */ |
3cf7f131 RM |
39 | #define POT_MAGIC1 0x54544f50 /* POTT */ |
40 | #define POT_MAGIC2 0x504f /* OP */ | |
41 | #define ML_MAGIC1 0x39685a42 | |
42 | #define ML_MAGIC2 0x26594131 | |
43 | #define TRX_MAGIC 0x30524448 | |
0b56d2d4 | 44 | #define SHSQ_MAGIC 0x71736873 /* shsq (weird ZTE H218N endianness) */ |
bd10c26a | 45 | #define UBI_EC_MAGIC 0x23494255 /* UBI# */ |
3cf7f131 RM |
46 | |
47 | struct trx_header { | |
48 | uint32_t magic; | |
49 | uint32_t length; | |
50 | uint32_t crc32; | |
51 | uint16_t flags; | |
52 | uint16_t version; | |
53 | uint32_t offset[3]; | |
54 | } __packed; | |
55 | ||
bd10c26a | 56 | static void bcm47xxpart_add_part(struct mtd_partition *part, const char *name, |
3cf7f131 RM |
57 | u64 offset, uint32_t mask_flags) |
58 | { | |
59 | part->name = name; | |
60 | part->offset = offset; | |
61 | part->mask_flags = mask_flags; | |
62 | } | |
63 | ||
bd10c26a RM |
64 | static const char *bcm47xxpart_trx_data_part_name(struct mtd_info *master, |
65 | size_t offset) | |
66 | { | |
67 | uint32_t buf; | |
68 | size_t bytes_read; | |
69 | ||
70 | if (mtd_read(master, offset, sizeof(buf), &bytes_read, | |
71 | (uint8_t *)&buf) < 0) { | |
72 | pr_err("mtd_read error while parsing (offset: 0x%X)!\n", | |
73 | offset); | |
74 | goto out_default; | |
75 | } | |
76 | ||
77 | if (buf == UBI_EC_MAGIC) | |
78 | return "ubi"; | |
79 | ||
80 | out_default: | |
81 | return "rootfs"; | |
82 | } | |
83 | ||
3cf7f131 RM |
84 | static int bcm47xxpart_parse(struct mtd_info *master, |
85 | struct mtd_partition **pparts, | |
86 | struct mtd_part_parser_data *data) | |
87 | { | |
88 | struct mtd_partition *parts; | |
89 | uint8_t i, curr_part = 0; | |
90 | uint32_t *buf; | |
91 | size_t bytes_read; | |
92 | uint32_t offset; | |
25bad1d3 | 93 | uint32_t blocksize = master->erasesize; |
3cf7f131 | 94 | struct trx_header *trx; |
396afe55 RM |
95 | int trx_part = -1; |
96 | int last_trx_part = -1; | |
91d542f4 | 97 | int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, }; |
3cf7f131 | 98 | |
16bd87b3 RM |
99 | /* |
100 | * Some really old flashes (like AT45DB*) had smaller erasesize-s, but | |
101 | * partitions were aligned to at least 0x1000 anyway. | |
102 | */ | |
103 | if (blocksize < 0x1000) | |
104 | blocksize = 0x1000; | |
3cf7f131 RM |
105 | |
106 | /* Alloc */ | |
107 | parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS, | |
108 | GFP_KERNEL); | |
99b1d188 HM |
109 | if (!parts) |
110 | return -ENOMEM; | |
111 | ||
5ca1088f | 112 | buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL); |
99b1d188 HM |
113 | if (!buf) { |
114 | kfree(parts); | |
115 | return -ENOMEM; | |
116 | } | |
3cf7f131 RM |
117 | |
118 | /* Parse block by block looking for magics */ | |
119 | for (offset = 0; offset <= master->size - blocksize; | |
120 | offset += blocksize) { | |
121 | /* Nothing more in higher memory */ | |
122 | if (offset >= 0x2000000) | |
123 | break; | |
124 | ||
00b79860 | 125 | if (curr_part >= BCM47XXPART_MAX_PARTS) { |
3cf7f131 RM |
126 | pr_warn("Reached maximum number of partitions, scanning stopped!\n"); |
127 | break; | |
128 | } | |
129 | ||
130 | /* Read beginning of the block */ | |
5ca1088f | 131 | if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ, |
3cf7f131 RM |
132 | &bytes_read, (uint8_t *)buf) < 0) { |
133 | pr_err("mtd_read error while parsing (offset: 0x%X)!\n", | |
134 | offset); | |
135 | continue; | |
136 | } | |
137 | ||
4f8aaf72 RM |
138 | /* Magic or small NVRAM at 0x400 */ |
139 | if ((buf[0x4e0 / 4] == CFE_MAGIC && buf[0x4e4 / 4] == CFE_MAGIC) || | |
140 | (buf[0x400 / 4] == NVRAM_HEADER)) { | |
3cf7f131 RM |
141 | bcm47xxpart_add_part(&parts[curr_part++], "boot", |
142 | offset, MTD_WRITEABLE); | |
143 | continue; | |
144 | } | |
145 | ||
3cf7f131 RM |
146 | /* |
147 | * board_data starts with board_id which differs across boards, | |
148 | * but we can use 'MPFR' (hopefully) magic at 0x100 | |
149 | */ | |
150 | if (buf[0x100 / 4] == BOARD_DATA_MAGIC) { | |
151 | bcm47xxpart_add_part(&parts[curr_part++], "board_data", | |
152 | offset, MTD_WRITEABLE); | |
153 | continue; | |
154 | } | |
155 | ||
33094c73 RM |
156 | /* Found on Huawei E970 */ |
157 | if (buf[0x000 / 4] == FACTORY_MAGIC) { | |
158 | bcm47xxpart_add_part(&parts[curr_part++], "factory", | |
159 | offset, MTD_WRITEABLE); | |
160 | continue; | |
161 | } | |
162 | ||
3cf7f131 RM |
163 | /* POT(TOP) */ |
164 | if (buf[0x000 / 4] == POT_MAGIC1 && | |
165 | (buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) { | |
166 | bcm47xxpart_add_part(&parts[curr_part++], "POT", offset, | |
167 | MTD_WRITEABLE); | |
168 | continue; | |
169 | } | |
170 | ||
171 | /* ML */ | |
172 | if (buf[0x010 / 4] == ML_MAGIC1 && | |
173 | buf[0x014 / 4] == ML_MAGIC2) { | |
174 | bcm47xxpart_add_part(&parts[curr_part++], "ML", offset, | |
175 | MTD_WRITEABLE); | |
176 | continue; | |
177 | } | |
178 | ||
179 | /* TRX */ | |
180 | if (buf[0x000 / 4] == TRX_MAGIC) { | |
108ebcd8 RM |
181 | if (BCM47XXPART_MAX_PARTS - curr_part < 4) { |
182 | pr_warn("Not enough partitions left to register trx, scanning stopped!\n"); | |
183 | break; | |
184 | } | |
185 | ||
3cf7f131 RM |
186 | trx = (struct trx_header *)buf; |
187 | ||
396afe55 RM |
188 | trx_part = curr_part; |
189 | bcm47xxpart_add_part(&parts[curr_part++], "firmware", | |
190 | offset, 0); | |
191 | ||
3cf7f131 RM |
192 | i = 0; |
193 | /* We have LZMA loader if offset[2] points to sth */ | |
194 | if (trx->offset[2]) { | |
195 | bcm47xxpart_add_part(&parts[curr_part++], | |
196 | "loader", | |
197 | offset + trx->offset[i], | |
198 | 0); | |
199 | i++; | |
200 | } | |
201 | ||
a1ff7d64 HM |
202 | if (trx->offset[i]) { |
203 | bcm47xxpart_add_part(&parts[curr_part++], | |
204 | "linux", | |
205 | offset + trx->offset[i], | |
206 | 0); | |
207 | i++; | |
208 | } | |
3cf7f131 RM |
209 | |
210 | /* | |
211 | * Pure rootfs size is known and can be calculated as: | |
212 | * trx->length - trx->offset[i]. We don't fill it as | |
213 | * we want to have jffs2 (overlay) in the same mtd. | |
214 | */ | |
a1ff7d64 | 215 | if (trx->offset[i]) { |
bd10c26a RM |
216 | const char *name; |
217 | ||
218 | name = bcm47xxpart_trx_data_part_name(master, offset + trx->offset[i]); | |
a1ff7d64 | 219 | bcm47xxpart_add_part(&parts[curr_part++], |
bd10c26a | 220 | name, |
a1ff7d64 HM |
221 | offset + trx->offset[i], |
222 | 0); | |
223 | i++; | |
224 | } | |
3cf7f131 | 225 | |
396afe55 RM |
226 | last_trx_part = curr_part - 1; |
227 | ||
3cf7f131 RM |
228 | /* |
229 | * We have whole TRX scanned, skip to the next part. Use | |
230 | * roundown (not roundup), as the loop will increase | |
231 | * offset in next step. | |
232 | */ | |
233 | offset = rounddown(offset + trx->length, blocksize); | |
234 | continue; | |
235 | } | |
020c6bcf RM |
236 | |
237 | /* Squashfs on devices not using TRX */ | |
0b56d2d4 RM |
238 | if (le32_to_cpu(buf[0x000 / 4]) == SQUASHFS_MAGIC || |
239 | buf[0x000 / 4] == SHSQ_MAGIC) { | |
020c6bcf RM |
240 | bcm47xxpart_add_part(&parts[curr_part++], "rootfs", |
241 | offset, 0); | |
242 | continue; | |
024629fd RM |
243 | } |
244 | ||
245 | /* | |
246 | * New (ARM?) devices may have NVRAM in some middle block. Last | |
247 | * block will be checked later, so skip it. | |
248 | */ | |
249 | if (offset != master->size - blocksize && | |
250 | buf[0x000 / 4] == NVRAM_HEADER) { | |
251 | bcm47xxpart_add_part(&parts[curr_part++], "nvram", | |
252 | offset, 0); | |
253 | continue; | |
020c6bcf | 254 | } |
f0501e81 RM |
255 | |
256 | /* Read middle of the block */ | |
257 | if (mtd_read(master, offset + 0x8000, 0x4, | |
258 | &bytes_read, (uint8_t *)buf) < 0) { | |
259 | pr_err("mtd_read error while parsing (offset: 0x%X)!\n", | |
260 | offset); | |
261 | continue; | |
262 | } | |
263 | ||
264 | /* Some devices (ex. WNDR3700v3) don't have a standard 'MPFR' */ | |
265 | if (buf[0x000 / 4] == BOARD_DATA_MAGIC2) { | |
266 | bcm47xxpart_add_part(&parts[curr_part++], "board_data", | |
267 | offset, MTD_WRITEABLE); | |
268 | continue; | |
269 | } | |
3cf7f131 | 270 | } |
91d542f4 RM |
271 | |
272 | /* Look for NVRAM at the end of the last block. */ | |
273 | for (i = 0; i < ARRAY_SIZE(possible_nvram_sizes); i++) { | |
00b79860 | 274 | if (curr_part >= BCM47XXPART_MAX_PARTS) { |
91d542f4 RM |
275 | pr_warn("Reached maximum number of partitions, scanning stopped!\n"); |
276 | break; | |
277 | } | |
278 | ||
279 | offset = master->size - possible_nvram_sizes[i]; | |
280 | if (mtd_read(master, offset, 0x4, &bytes_read, | |
281 | (uint8_t *)buf) < 0) { | |
282 | pr_err("mtd_read error while reading at offset 0x%X!\n", | |
283 | offset); | |
284 | continue; | |
285 | } | |
286 | ||
287 | /* Standard NVRAM */ | |
288 | if (buf[0] == NVRAM_HEADER) { | |
289 | bcm47xxpart_add_part(&parts[curr_part++], "nvram", | |
290 | master->size - blocksize, 0); | |
291 | break; | |
292 | } | |
293 | } | |
294 | ||
3cf7f131 RM |
295 | kfree(buf); |
296 | ||
297 | /* | |
298 | * Assume that partitions end at the beginning of the one they are | |
299 | * followed by. | |
300 | */ | |
648bdbee RM |
301 | for (i = 0; i < curr_part; i++) { |
302 | u64 next_part_offset = (i < curr_part - 1) ? | |
303 | parts[i + 1].offset : master->size; | |
304 | ||
305 | parts[i].size = next_part_offset - parts[i].offset; | |
396afe55 RM |
306 | if (i == last_trx_part && trx_part >= 0) |
307 | parts[trx_part].size = next_part_offset - | |
308 | parts[trx_part].offset; | |
648bdbee | 309 | } |
3cf7f131 RM |
310 | |
311 | *pparts = parts; | |
312 | return curr_part; | |
313 | }; | |
314 | ||
315 | static struct mtd_part_parser bcm47xxpart_mtd_parser = { | |
316 | .owner = THIS_MODULE, | |
317 | .parse_fn = bcm47xxpart_parse, | |
318 | .name = "bcm47xxpart", | |
319 | }; | |
320 | ||
321 | static int __init bcm47xxpart_init(void) | |
322 | { | |
6e14a61d AL |
323 | register_mtd_parser(&bcm47xxpart_mtd_parser); |
324 | return 0; | |
3cf7f131 RM |
325 | } |
326 | ||
327 | static void __exit bcm47xxpart_exit(void) | |
328 | { | |
329 | deregister_mtd_parser(&bcm47xxpart_mtd_parser); | |
330 | } | |
331 | ||
332 | module_init(bcm47xxpart_init); | |
333 | module_exit(bcm47xxpart_exit); | |
334 | ||
335 | MODULE_LICENSE("GPL"); | |
336 | MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories"); |