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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 1.13 2004/02/27 22:09:59 rmk 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 | ||
39 | struct 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 | ||
47 | struct 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 | ||
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(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 | ||
130 | static int | |
131 | afs_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 | ||
166 | static 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 = kmalloc(sz, GFP_KERNEL); | |
211 | if (!parts) | |
212 | return -ENOMEM; | |
213 | ||
214 | memset(parts, 0, sz); | |
215 | str = (char *)(parts + idx); | |
216 | ||
217 | /* | |
218 | * Identify the partitions | |
219 | */ | |
220 | for (idx = off = 0; off < mtd->size; off += mtd->erasesize) { | |
221 | struct image_info_struct iis; | |
222 | u_int iis_ptr, img_ptr, size; | |
223 | ||
224 | /* Read the footer. */ | |
225 | ret = afs_read_footer(mtd, &img_ptr, &iis_ptr, off, mask); | |
226 | if (ret < 0) | |
227 | break; | |
228 | if (ret == 0) | |
229 | continue; | |
230 | ||
231 | /* Read the image info block */ | |
232 | ret = afs_read_iis(mtd, &iis, iis_ptr); | |
233 | if (ret < 0) | |
234 | break; | |
235 | if (ret == 0) | |
236 | continue; | |
237 | ||
238 | strcpy(str, iis.name); | |
239 | size = mtd->erasesize + off - img_ptr; | |
240 | ||
241 | /* | |
242 | * In order to support JFFS2 partitions on this layout, | |
243 | * we must lie to MTD about the real size of JFFS2 | |
244 | * partitions; this ensures that the AFS flash footer | |
245 | * won't be erased by JFFS2. Please ensure that your | |
246 | * JFFS2 partitions are given image numbers between | |
247 | * 1000 and 2000 inclusive. | |
248 | */ | |
249 | if (iis.imageNumber >= 1000 && iis.imageNumber < 2000) | |
250 | size -= mtd->erasesize; | |
251 | ||
252 | parts[idx].name = str; | |
253 | parts[idx].size = size; | |
254 | parts[idx].offset = img_ptr; | |
255 | parts[idx].mask_flags = 0; | |
256 | ||
257 | printk(" mtd%d: at 0x%08x, %5dKB, %8u, %s\n", | |
258 | idx, img_ptr, parts[idx].size / 1024, | |
259 | iis.imageNumber, str); | |
260 | ||
261 | idx += 1; | |
262 | str = str + strlen(iis.name) + 1; | |
263 | } | |
264 | ||
265 | if (!idx) { | |
266 | kfree(parts); | |
267 | parts = NULL; | |
268 | } | |
269 | ||
270 | *pparts = parts; | |
271 | return idx ? idx : ret; | |
272 | } | |
273 | ||
274 | static struct mtd_part_parser afs_parser = { | |
275 | .owner = THIS_MODULE, | |
276 | .parse_fn = parse_afs_partitions, | |
277 | .name = "afs", | |
278 | }; | |
279 | ||
280 | static int __init afs_parser_init(void) | |
281 | { | |
282 | return register_mtd_parser(&afs_parser); | |
283 | } | |
284 | ||
285 | static void __exit afs_parser_exit(void) | |
286 | { | |
287 | deregister_mtd_parser(&afs_parser); | |
288 | } | |
289 | ||
290 | module_init(afs_parser_init); | |
291 | module_exit(afs_parser_exit); | |
292 | ||
293 | ||
294 | MODULE_AUTHOR("ARM Ltd"); | |
295 | MODULE_DESCRIPTION("ARM Firmware Suite partition parser"); | |
296 | MODULE_LICENSE("GPL"); |