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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3cf7f131 RM |
2 | /* |
3 | * BCM47XX MTD partitioning | |
4 | * | |
5 | * Copyright © 2012 Rafał Miłecki <zajec5@gmail.com> | |
3cf7f131 RM |
6 | */ |
7 | ||
89a0d9a9 | 8 | #include <linux/bcm47xx_nvram.h> |
3cf7f131 RM |
9 | #include <linux/module.h> |
10 | #include <linux/kernel.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/mtd/mtd.h> | |
13 | #include <linux/mtd/partitions.h> | |
3cf7f131 | 14 | |
0b56d2d4 RM |
15 | #include <uapi/linux/magic.h> |
16 | ||
59af5c7a RM |
17 | /* |
18 | * NAND flash on Netgear R6250 was verified to contain 15 partitions. | |
19 | * This will result in allocating too big array for some old devices, but the | |
20 | * memory will be freed soon anyway (see mtd_device_parse_register). | |
21 | */ | |
22 | #define BCM47XXPART_MAX_PARTS 20 | |
3cf7f131 | 23 | |
5ca1088f RM |
24 | /* |
25 | * Amount of bytes we read when analyzing each block of flash memory. | |
26 | * Set it big enough to allow detecting partition and reading important data. | |
27 | */ | |
4f8aaf72 | 28 | #define BCM47XXPART_BYTES_TO_READ 0x4e8 |
5ca1088f | 29 | |
3cf7f131 RM |
30 | /* Magics */ |
31 | #define BOARD_DATA_MAGIC 0x5246504D /* MPFR */ | |
f0501e81 | 32 | #define BOARD_DATA_MAGIC2 0xBD0D0BBD |
4f8aaf72 | 33 | #define CFE_MAGIC 0x43464531 /* 1EFC */ |
33094c73 | 34 | #define FACTORY_MAGIC 0x59544346 /* FCTY */ |
9e3afa5f | 35 | #define NVRAM_HEADER 0x48534C46 /* FLSH */ |
3cf7f131 RM |
36 | #define POT_MAGIC1 0x54544f50 /* POTT */ |
37 | #define POT_MAGIC2 0x504f /* OP */ | |
38 | #define ML_MAGIC1 0x39685a42 | |
39 | #define ML_MAGIC2 0x26594131 | |
40 | #define TRX_MAGIC 0x30524448 | |
0b56d2d4 | 41 | #define SHSQ_MAGIC 0x71736873 /* shsq (weird ZTE H218N endianness) */ |
99352afe RM |
42 | |
43 | static const char * const trx_types[] = { "trx", NULL }; | |
3cf7f131 RM |
44 | |
45 | struct trx_header { | |
46 | uint32_t magic; | |
47 | uint32_t length; | |
48 | uint32_t crc32; | |
49 | uint16_t flags; | |
50 | uint16_t version; | |
51 | uint32_t offset[3]; | |
52 | } __packed; | |
53 | ||
bd10c26a | 54 | static void bcm47xxpart_add_part(struct mtd_partition *part, const char *name, |
3cf7f131 RM |
55 | u64 offset, uint32_t mask_flags) |
56 | { | |
57 | part->name = name; | |
58 | part->offset = offset; | |
59 | part->mask_flags = mask_flags; | |
60 | } | |
61 | ||
89a0d9a9 RM |
62 | /** |
63 | * bcm47xxpart_bootpartition - gets index of TRX partition used by bootloader | |
64 | * | |
65 | * Some devices may have more than one TRX partition. In such case one of them | |
66 | * is the main one and another a failsafe one. Bootloader may fallback to the | |
67 | * failsafe firmware if it detects corruption of the main image. | |
68 | * | |
69 | * This function provides info about currently used TRX partition. It's the one | |
70 | * containing kernel started by the bootloader. | |
71 | */ | |
72 | static int bcm47xxpart_bootpartition(void) | |
73 | { | |
74 | char buf[4]; | |
75 | int bootpartition; | |
76 | ||
77 | /* Check CFE environment variable */ | |
78 | if (bcm47xx_nvram_getenv("bootpartition", buf, sizeof(buf)) > 0) { | |
79 | if (!kstrtoint(buf, 0, &bootpartition)) | |
80 | return bootpartition; | |
81 | } | |
82 | ||
83 | return 0; | |
84 | } | |
85 | ||
3cf7f131 | 86 | static int bcm47xxpart_parse(struct mtd_info *master, |
b9adf469 | 87 | const struct mtd_partition **pparts, |
3cf7f131 RM |
88 | struct mtd_part_parser_data *data) |
89 | { | |
90 | struct mtd_partition *parts; | |
91 | uint8_t i, curr_part = 0; | |
92 | uint32_t *buf; | |
93 | size_t bytes_read; | |
94 | uint32_t offset; | |
25bad1d3 | 95 | uint32_t blocksize = master->erasesize; |
89a0d9a9 RM |
96 | int trx_parts[2]; /* Array with indexes of TRX partitions */ |
97 | int trx_num = 0; /* Number of found TRX partitions */ | |
91d542f4 | 98 | int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, }; |
36bcc0c9 | 99 | int err; |
3cf7f131 | 100 | |
16bd87b3 RM |
101 | /* |
102 | * Some really old flashes (like AT45DB*) had smaller erasesize-s, but | |
103 | * partitions were aligned to at least 0x1000 anyway. | |
104 | */ | |
105 | if (blocksize < 0x1000) | |
106 | blocksize = 0x1000; | |
3cf7f131 RM |
107 | |
108 | /* Alloc */ | |
6396bb22 | 109 | parts = kcalloc(BCM47XXPART_MAX_PARTS, sizeof(struct mtd_partition), |
3cf7f131 | 110 | GFP_KERNEL); |
99b1d188 HM |
111 | if (!parts) |
112 | return -ENOMEM; | |
113 | ||
5ca1088f | 114 | buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL); |
99b1d188 HM |
115 | if (!buf) { |
116 | kfree(parts); | |
117 | return -ENOMEM; | |
118 | } | |
3cf7f131 RM |
119 | |
120 | /* Parse block by block looking for magics */ | |
121 | for (offset = 0; offset <= master->size - blocksize; | |
122 | offset += blocksize) { | |
2a36a5c3 | 123 | /* Nothing more in higher memory on BCM47XX (MIPS) */ |
97f2645f | 124 | if (IS_ENABLED(CONFIG_BCM47XX) && offset >= 0x2000000) |
3cf7f131 RM |
125 | break; |
126 | ||
00b79860 | 127 | if (curr_part >= BCM47XXPART_MAX_PARTS) { |
3cf7f131 RM |
128 | pr_warn("Reached maximum number of partitions, scanning stopped!\n"); |
129 | break; | |
130 | } | |
131 | ||
132 | /* Read beginning of the block */ | |
36bcc0c9 RM |
133 | err = mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ, |
134 | &bytes_read, (uint8_t *)buf); | |
135 | if (err && !mtd_is_bitflip(err)) { | |
136 | pr_err("mtd_read error while parsing (offset: 0x%X): %d\n", | |
137 | offset, err); | |
3cf7f131 RM |
138 | continue; |
139 | } | |
140 | ||
4f8aaf72 RM |
141 | /* Magic or small NVRAM at 0x400 */ |
142 | if ((buf[0x4e0 / 4] == CFE_MAGIC && buf[0x4e4 / 4] == CFE_MAGIC) || | |
143 | (buf[0x400 / 4] == NVRAM_HEADER)) { | |
3cf7f131 RM |
144 | bcm47xxpart_add_part(&parts[curr_part++], "boot", |
145 | offset, MTD_WRITEABLE); | |
146 | continue; | |
147 | } | |
148 | ||
3cf7f131 RM |
149 | /* |
150 | * board_data starts with board_id which differs across boards, | |
151 | * but we can use 'MPFR' (hopefully) magic at 0x100 | |
152 | */ | |
153 | if (buf[0x100 / 4] == BOARD_DATA_MAGIC) { | |
154 | bcm47xxpart_add_part(&parts[curr_part++], "board_data", | |
155 | offset, MTD_WRITEABLE); | |
156 | continue; | |
157 | } | |
158 | ||
33094c73 RM |
159 | /* Found on Huawei E970 */ |
160 | if (buf[0x000 / 4] == FACTORY_MAGIC) { | |
161 | bcm47xxpart_add_part(&parts[curr_part++], "factory", | |
162 | offset, MTD_WRITEABLE); | |
163 | continue; | |
164 | } | |
165 | ||
3cf7f131 RM |
166 | /* POT(TOP) */ |
167 | if (buf[0x000 / 4] == POT_MAGIC1 && | |
168 | (buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) { | |
169 | bcm47xxpart_add_part(&parts[curr_part++], "POT", offset, | |
170 | MTD_WRITEABLE); | |
171 | continue; | |
172 | } | |
173 | ||
174 | /* ML */ | |
175 | if (buf[0x010 / 4] == ML_MAGIC1 && | |
176 | buf[0x014 / 4] == ML_MAGIC2) { | |
177 | bcm47xxpart_add_part(&parts[curr_part++], "ML", offset, | |
178 | MTD_WRITEABLE); | |
179 | continue; | |
180 | } | |
181 | ||
182 | /* TRX */ | |
183 | if (buf[0x000 / 4] == TRX_MAGIC) { | |
b522d7b0 | 184 | struct trx_header *trx; |
237ea0d4 RM |
185 | uint32_t last_subpart; |
186 | uint32_t trx_size; | |
3cf7f131 | 187 | |
89a0d9a9 RM |
188 | if (trx_num >= ARRAY_SIZE(trx_parts)) |
189 | pr_warn("No enough space to store another TRX found at 0x%X\n", | |
190 | offset); | |
191 | else | |
192 | trx_parts[trx_num++] = curr_part; | |
396afe55 RM |
193 | bcm47xxpart_add_part(&parts[curr_part++], "firmware", |
194 | offset, 0); | |
195 | ||
237ea0d4 RM |
196 | /* |
197 | * Try to find TRX size. The "length" field isn't fully | |
198 | * reliable as it could be decreased to make CRC32 cover | |
199 | * only part of TRX data. It's commonly used as checksum | |
200 | * can't cover e.g. ever-changing rootfs partition. | |
201 | * Use offsets as helpers for assuming min TRX size. | |
202 | */ | |
b522d7b0 | 203 | trx = (struct trx_header *)buf; |
237ea0d4 RM |
204 | last_subpart = max3(trx->offset[0], trx->offset[1], |
205 | trx->offset[2]); | |
206 | trx_size = max(trx->length, last_subpart + blocksize); | |
207 | ||
208 | /* | |
209 | * Skip the TRX data. Decrease offset by block size as | |
210 | * the next loop iteration will increase it. | |
211 | */ | |
212 | offset += roundup(trx_size, blocksize) - blocksize; | |
3cf7f131 RM |
213 | continue; |
214 | } | |
020c6bcf RM |
215 | |
216 | /* Squashfs on devices not using TRX */ | |
0b56d2d4 RM |
217 | if (le32_to_cpu(buf[0x000 / 4]) == SQUASHFS_MAGIC || |
218 | buf[0x000 / 4] == SHSQ_MAGIC) { | |
020c6bcf RM |
219 | bcm47xxpart_add_part(&parts[curr_part++], "rootfs", |
220 | offset, 0); | |
221 | continue; | |
024629fd RM |
222 | } |
223 | ||
224 | /* | |
225 | * New (ARM?) devices may have NVRAM in some middle block. Last | |
226 | * block will be checked later, so skip it. | |
227 | */ | |
228 | if (offset != master->size - blocksize && | |
229 | buf[0x000 / 4] == NVRAM_HEADER) { | |
230 | bcm47xxpart_add_part(&parts[curr_part++], "nvram", | |
231 | offset, 0); | |
232 | continue; | |
020c6bcf | 233 | } |
f0501e81 RM |
234 | |
235 | /* Read middle of the block */ | |
05e258c6 | 236 | err = mtd_read(master, offset + (blocksize / 2), 0x4, &bytes_read, |
36bcc0c9 RM |
237 | (uint8_t *)buf); |
238 | if (err && !mtd_is_bitflip(err)) { | |
239 | pr_err("mtd_read error while parsing (offset: 0x%X): %d\n", | |
05e258c6 | 240 | offset + (blocksize / 2), err); |
f0501e81 RM |
241 | continue; |
242 | } | |
243 | ||
244 | /* Some devices (ex. WNDR3700v3) don't have a standard 'MPFR' */ | |
245 | if (buf[0x000 / 4] == BOARD_DATA_MAGIC2) { | |
246 | bcm47xxpart_add_part(&parts[curr_part++], "board_data", | |
247 | offset, MTD_WRITEABLE); | |
248 | continue; | |
249 | } | |
3cf7f131 | 250 | } |
91d542f4 RM |
251 | |
252 | /* Look for NVRAM at the end of the last block. */ | |
253 | for (i = 0; i < ARRAY_SIZE(possible_nvram_sizes); i++) { | |
00b79860 | 254 | if (curr_part >= BCM47XXPART_MAX_PARTS) { |
91d542f4 RM |
255 | pr_warn("Reached maximum number of partitions, scanning stopped!\n"); |
256 | break; | |
257 | } | |
258 | ||
259 | offset = master->size - possible_nvram_sizes[i]; | |
36bcc0c9 RM |
260 | err = mtd_read(master, offset, 0x4, &bytes_read, |
261 | (uint8_t *)buf); | |
262 | if (err && !mtd_is_bitflip(err)) { | |
263 | pr_err("mtd_read error while reading (offset 0x%X): %d\n", | |
264 | offset, err); | |
91d542f4 RM |
265 | continue; |
266 | } | |
267 | ||
268 | /* Standard NVRAM */ | |
269 | if (buf[0] == NVRAM_HEADER) { | |
270 | bcm47xxpart_add_part(&parts[curr_part++], "nvram", | |
271 | master->size - blocksize, 0); | |
272 | break; | |
273 | } | |
274 | } | |
275 | ||
3cf7f131 RM |
276 | kfree(buf); |
277 | ||
278 | /* | |
279 | * Assume that partitions end at the beginning of the one they are | |
280 | * followed by. | |
281 | */ | |
648bdbee RM |
282 | for (i = 0; i < curr_part; i++) { |
283 | u64 next_part_offset = (i < curr_part - 1) ? | |
284 | parts[i + 1].offset : master->size; | |
285 | ||
286 | parts[i].size = next_part_offset - parts[i].offset; | |
b522d7b0 RM |
287 | } |
288 | ||
289 | /* If there was TRX parse it now */ | |
89a0d9a9 RM |
290 | for (i = 0; i < trx_num; i++) { |
291 | struct mtd_partition *trx = &parts[trx_parts[i]]; | |
292 | ||
99352afe RM |
293 | if (i == bcm47xxpart_bootpartition()) |
294 | trx->types = trx_types; | |
295 | else | |
89a0d9a9 | 296 | trx->name = "failsafe"; |
648bdbee | 297 | } |
3cf7f131 RM |
298 | |
299 | *pparts = parts; | |
300 | return curr_part; | |
301 | }; | |
302 | ||
cf589ce7 RM |
303 | static const struct of_device_id bcm47xxpart_of_match_table[] = { |
304 | { .compatible = "brcm,bcm947xx-cfe-partitions" }, | |
305 | {}, | |
306 | }; | |
307 | MODULE_DEVICE_TABLE(of, bcm47xxpart_of_match_table); | |
308 | ||
3cf7f131 | 309 | static struct mtd_part_parser bcm47xxpart_mtd_parser = { |
3cf7f131 RM |
310 | .parse_fn = bcm47xxpart_parse, |
311 | .name = "bcm47xxpart", | |
cf589ce7 | 312 | .of_match_table = bcm47xxpart_of_match_table, |
3cf7f131 | 313 | }; |
b8f70bad | 314 | module_mtd_part_parser(bcm47xxpart_mtd_parser); |
3cf7f131 RM |
315 | |
316 | MODULE_LICENSE("GPL"); | |
317 | MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories"); |