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1/*
2 * Parse RedBoot-style Flash Image System (FIS) tables and
3 * produce a Linux partition array to match.
4 *
5 * Copyright © 2001 Red Hat UK Limited
6 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24#include <linux/kernel.h>
25#include <linux/slab.h>
26#include <linux/init.h>
27#include <linux/vmalloc.h>
28
29#include <linux/mtd/mtd.h>
30#include <linux/mtd/partitions.h>
31#include <linux/module.h>
32
33struct fis_image_desc {
34 unsigned char name[16]; // Null terminated name
35 uint32_t flash_base; // Address within FLASH of image
36 uint32_t mem_base; // Address in memory where it executes
37 uint32_t size; // Length of image
38 uint32_t entry_point; // Execution entry point
39 uint32_t data_length; // Length of actual data
40 unsigned char _pad[256-(16+7*sizeof(uint32_t))];
41 uint32_t desc_cksum; // Checksum over image descriptor
42 uint32_t file_cksum; // Checksum over image data
43};
44
45struct fis_list {
46 struct fis_image_desc *img;
47 struct fis_list *next;
48};
49
50static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
51module_param(directory, int, 0);
52
53static inline int redboot_checksum(struct fis_image_desc *img)
54{
55 /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
56 return 1;
57}
58
59static int parse_redboot_partitions(struct mtd_info *master,
60 const struct mtd_partition **pparts,
61 struct mtd_part_parser_data *data)
62{
63 int nrparts = 0;
64 struct fis_image_desc *buf;
65 struct mtd_partition *parts;
66 struct fis_list *fl = NULL, *tmp_fl;
67 int ret, i;
68 size_t retlen;
69 char *names;
70 char *nullname;
71 int namelen = 0;
72 int nulllen = 0;
73 int numslots;
74 unsigned long offset;
75#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
76 static char nullstring[] = "unallocated";
77#endif
78
79 if ( directory < 0 ) {
80 offset = master->size + directory * master->erasesize;
81 while (mtd_block_isbad(master, offset)) {
82 if (!offset) {
83 nogood:
84 printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n");
85 return -EIO;
86 }
87 offset -= master->erasesize;
88 }
89 } else {
90 offset = directory * master->erasesize;
91 while (mtd_block_isbad(master, offset)) {
92 offset += master->erasesize;
93 if (offset == master->size)
94 goto nogood;
95 }
96 }
97 buf = vmalloc(master->erasesize);
98
99 if (!buf)
100 return -ENOMEM;
101
102 printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
103 master->name, offset);
104
105 ret = mtd_read(master, offset, master->erasesize, &retlen,
106 (void *)buf);
107
108 if (ret)
109 goto out;
110
111 if (retlen != master->erasesize) {
112 ret = -EIO;
113 goto out;
114 }
115
116 numslots = (master->erasesize / sizeof(struct fis_image_desc));
117 for (i = 0; i < numslots; i++) {
118 if (!memcmp(buf[i].name, "FIS directory", 14)) {
119 /* This is apparently the FIS directory entry for the
120 * FIS directory itself. The FIS directory size is
121 * one erase block; if the buf[i].size field is
122 * swab32(erasesize) then we know we are looking at
123 * a byte swapped FIS directory - swap all the entries!
124 * (NOTE: this is 'size' not 'data_length'; size is
125 * the full size of the entry.)
126 */
127
128 /* RedBoot can combine the FIS directory and
129 config partitions into a single eraseblock;
130 we assume wrong-endian if either the swapped
131 'size' matches the eraseblock size precisely,
132 or if the swapped size actually fits in an
133 eraseblock while the unswapped size doesn't. */
134 if (swab32(buf[i].size) == master->erasesize ||
135 (buf[i].size > master->erasesize
136 && swab32(buf[i].size) < master->erasesize)) {
137 int j;
138 /* Update numslots based on actual FIS directory size */
139 numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc);
140 for (j = 0; j < numslots; ++j) {
141
142 /* A single 0xff denotes a deleted entry.
143 * Two of them in a row is the end of the table.
144 */
145 if (buf[j].name[0] == 0xff) {
146 if (buf[j].name[1] == 0xff) {
147 break;
148 } else {
149 continue;
150 }
151 }
152
153 /* The unsigned long fields were written with the
154 * wrong byte sex, name and pad have no byte sex.
155 */
156 swab32s(&buf[j].flash_base);
157 swab32s(&buf[j].mem_base);
158 swab32s(&buf[j].size);
159 swab32s(&buf[j].entry_point);
160 swab32s(&buf[j].data_length);
161 swab32s(&buf[j].desc_cksum);
162 swab32s(&buf[j].file_cksum);
163 }
164 } else if (buf[i].size < master->erasesize) {
165 /* Update numslots based on actual FIS directory size */
166 numslots = buf[i].size / sizeof(struct fis_image_desc);
167 }
168 break;
169 }
170 }
171 if (i == numslots) {
172 /* Didn't find it */
173 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
174 master->name);
175 ret = 0;
176 goto out;
177 }
178
179 for (i = 0; i < numslots; i++) {
180 struct fis_list *new_fl, **prev;
181
182 if (buf[i].name[0] == 0xff) {
183 if (buf[i].name[1] == 0xff) {
184 break;
185 } else {
186 continue;
187 }
188 }
189 if (!redboot_checksum(&buf[i]))
190 break;
191
192 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
193 namelen += strlen(buf[i].name)+1;
194 if (!new_fl) {
195 ret = -ENOMEM;
196 goto out;
197 }
198 new_fl->img = &buf[i];
199 if (data && data->origin)
200 buf[i].flash_base -= data->origin;
201 else
202 buf[i].flash_base &= master->size-1;
203
204 /* I'm sure the JFFS2 code has done me permanent damage.
205 * I now think the following is _normal_
206 */
207 prev = &fl;
208 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
209 prev = &(*prev)->next;
210 new_fl->next = *prev;
211 *prev = new_fl;
212
213 nrparts++;
214 }
215#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
216 if (fl->img->flash_base) {
217 nrparts++;
218 nulllen = sizeof(nullstring);
219 }
220
221 for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
222 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
223 nrparts++;
224 nulllen = sizeof(nullstring);
225 }
226 }
227#endif
228 parts = kzalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
229
230 if (!parts) {
231 ret = -ENOMEM;
232 goto out;
233 }
234
235 nullname = (char *)&parts[nrparts];
236#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
237 if (nulllen > 0) {
238 strcpy(nullname, nullstring);
239 }
240#endif
241 names = nullname + nulllen;
242
243 i=0;
244
245#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
246 if (fl->img->flash_base) {
247 parts[0].name = nullname;
248 parts[0].size = fl->img->flash_base;
249 parts[0].offset = 0;
250 i++;
251 }
252#endif
253 for ( ; i<nrparts; i++) {
254 parts[i].size = fl->img->size;
255 parts[i].offset = fl->img->flash_base;
256 parts[i].name = names;
257
258 strcpy(names, fl->img->name);
259#ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
260 if (!memcmp(names, "RedBoot", 8) ||
261 !memcmp(names, "RedBoot config", 15) ||
262 !memcmp(names, "FIS directory", 14)) {
263 parts[i].mask_flags = MTD_WRITEABLE;
264 }
265#endif
266 names += strlen(names)+1;
267
268#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
269 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
270 i++;
271 parts[i].offset = parts[i-1].size + parts[i-1].offset;
272 parts[i].size = fl->next->img->flash_base - parts[i].offset;
273 parts[i].name = nullname;
274 }
275#endif
276 tmp_fl = fl;
277 fl = fl->next;
278 kfree(tmp_fl);
279 }
280 ret = nrparts;
281 *pparts = parts;
282 out:
283 while (fl) {
284 struct fis_list *old = fl;
285 fl = fl->next;
286 kfree(old);
287 }
288 vfree(buf);
289 return ret;
290}
291
292static struct mtd_part_parser redboot_parser = {
293 .parse_fn = parse_redboot_partitions,
294 .name = "RedBoot",
295};
296module_mtd_part_parser(redboot_parser);
297
298/* mtd parsers will request the module by parser name */
299MODULE_ALIAS("RedBoot");
300MODULE_LICENSE("GPL");
301MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
302MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");