cpupower: Rename package from cpupowerutils to cpupower
[linux-2.6.git] / drivers / mtd / redboot.c
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
32 struct fis_image_desc {
33     unsigned char name[16];      // Null terminated name
34     uint32_t      flash_base;    // Address within FLASH of image
35     uint32_t      mem_base;      // Address in memory where it executes
36     uint32_t      size;          // Length of image
37     uint32_t      entry_point;   // Execution entry point
38     uint32_t      data_length;   // Length of actual data
39     unsigned char _pad[256-(16+7*sizeof(uint32_t))];
40     uint32_t      desc_cksum;    // Checksum over image descriptor
41     uint32_t      file_cksum;    // Checksum over image data
42 };
43
44 struct fis_list {
45         struct fis_image_desc *img;
46         struct fis_list *next;
47 };
48
49 static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
50 module_param(directory, int, 0);
51
52 static inline int redboot_checksum(struct fis_image_desc *img)
53 {
54         /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
55         return 1;
56 }
57
58 static int parse_redboot_partitions(struct mtd_info *master,
59                              struct mtd_partition **pparts,
60                              unsigned long fis_origin)
61 {
62         int nrparts = 0;
63         struct fis_image_desc *buf;
64         struct mtd_partition *parts;
65         struct fis_list *fl = NULL, *tmp_fl;
66         int ret, i;
67         size_t retlen;
68         char *names;
69         char *nullname;
70         int namelen = 0;
71         int nulllen = 0;
72         int numslots;
73         unsigned long offset;
74 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
75         static char nullstring[] = "unallocated";
76 #endif
77
78         if ( directory < 0 ) {
79                 offset = master->size + directory * master->erasesize;
80                 while (master->block_isbad && 
81                        master->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 (master->block_isbad && 
92                        master->block_isbad(master, offset)) {
93                         offset += master->erasesize;
94                         if (offset == master->size)
95                                 goto nogood;
96                 }
97         }
98         buf = vmalloc(master->erasesize);
99
100         if (!buf)
101                 return -ENOMEM;
102
103         printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
104                master->name, offset);
105
106         ret = master->read(master, offset,
107                            master->erasesize, &retlen, (void *)buf);
108
109         if (ret)
110                 goto out;
111
112         if (retlen != master->erasesize) {
113                 ret = -EIO;
114                 goto out;
115         }
116
117         numslots = (master->erasesize / sizeof(struct fis_image_desc));
118         for (i = 0; i < numslots; i++) {
119                 if (!memcmp(buf[i].name, "FIS directory", 14)) {
120                         /* This is apparently the FIS directory entry for the
121                          * FIS directory itself.  The FIS directory size is
122                          * one erase block; if the buf[i].size field is
123                          * swab32(erasesize) then we know we are looking at
124                          * a byte swapped FIS directory - swap all the entries!
125                          * (NOTE: this is 'size' not 'data_length'; size is
126                          * the full size of the entry.)
127                          */
128
129                         /* RedBoot can combine the FIS directory and
130                            config partitions into a single eraseblock;
131                            we assume wrong-endian if either the swapped
132                            'size' matches the eraseblock size precisely,
133                            or if the swapped size actually fits in an
134                            eraseblock while the unswapped size doesn't. */
135                         if (swab32(buf[i].size) == master->erasesize ||
136                             (buf[i].size > master->erasesize
137                              && swab32(buf[i].size) < master->erasesize)) {
138                                 int j;
139                                 /* Update numslots based on actual FIS directory size */
140                                 numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc);
141                                 for (j = 0; j < numslots; ++j) {
142
143                                         /* A single 0xff denotes a deleted entry.
144                                          * Two of them in a row is the end of the table.
145                                          */
146                                         if (buf[j].name[0] == 0xff) {
147                                                 if (buf[j].name[1] == 0xff) {
148                                                         break;
149                                                 } else {
150                                                         continue;
151                                                 }
152                                         }
153
154                                         /* The unsigned long fields were written with the
155                                          * wrong byte sex, name and pad have no byte sex.
156                                          */
157                                         swab32s(&buf[j].flash_base);
158                                         swab32s(&buf[j].mem_base);
159                                         swab32s(&buf[j].size);
160                                         swab32s(&buf[j].entry_point);
161                                         swab32s(&buf[j].data_length);
162                                         swab32s(&buf[j].desc_cksum);
163                                         swab32s(&buf[j].file_cksum);
164                                 }
165                         } else if (buf[i].size < master->erasesize) {
166                                 /* Update numslots based on actual FIS directory size */
167                                 numslots = buf[i].size / sizeof(struct fis_image_desc);
168                         }
169                         break;
170                 }
171         }
172         if (i == numslots) {
173                 /* Didn't find it */
174                 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
175                        master->name);
176                 ret = 0;
177                 goto out;
178         }
179
180         for (i = 0; i < numslots; i++) {
181                 struct fis_list *new_fl, **prev;
182
183                 if (buf[i].name[0] == 0xff) {
184                         if (buf[i].name[1] == 0xff) {
185                                 break;
186                         } else {
187                                 continue;
188                         }
189                 }
190                 if (!redboot_checksum(&buf[i]))
191                         break;
192
193                 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
194                 namelen += strlen(buf[i].name)+1;
195                 if (!new_fl) {
196                         ret = -ENOMEM;
197                         goto out;
198                 }
199                 new_fl->img = &buf[i];
200                 if (fis_origin) {
201                         buf[i].flash_base -= fis_origin;
202                 } else {
203                         buf[i].flash_base &= master->size-1;
204                 }
205
206                 /* I'm sure the JFFS2 code has done me permanent damage.
207                  * I now think the following is _normal_
208                  */
209                 prev = &fl;
210                 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
211                         prev = &(*prev)->next;
212                 new_fl->next = *prev;
213                 *prev = new_fl;
214
215                 nrparts++;
216         }
217 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
218         if (fl->img->flash_base) {
219                 nrparts++;
220                 nulllen = sizeof(nullstring);
221         }
222
223         for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
224                 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
225                         nrparts++;
226                         nulllen = sizeof(nullstring);
227                 }
228         }
229 #endif
230         parts = kzalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
231
232         if (!parts) {
233                 ret = -ENOMEM;
234                 goto out;
235         }
236
237         nullname = (char *)&parts[nrparts];
238 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
239         if (nulllen > 0) {
240                 strcpy(nullname, nullstring);
241         }
242 #endif
243         names = nullname + nulllen;
244
245         i=0;
246
247 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
248         if (fl->img->flash_base) {
249                parts[0].name = nullname;
250                parts[0].size = fl->img->flash_base;
251                parts[0].offset = 0;
252                 i++;
253         }
254 #endif
255         for ( ; i<nrparts; i++) {
256                 parts[i].size = fl->img->size;
257                 parts[i].offset = fl->img->flash_base;
258                 parts[i].name = names;
259
260                 strcpy(names, fl->img->name);
261 #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
262                 if (!memcmp(names, "RedBoot", 8) ||
263                                 !memcmp(names, "RedBoot config", 15) ||
264                                 !memcmp(names, "FIS directory", 14)) {
265                         parts[i].mask_flags = MTD_WRITEABLE;
266                 }
267 #endif
268                 names += strlen(names)+1;
269
270 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
271                 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
272                         i++;
273                         parts[i].offset = parts[i-1].size + parts[i-1].offset;
274                         parts[i].size = fl->next->img->flash_base - parts[i].offset;
275                         parts[i].name = nullname;
276                 }
277 #endif
278                 tmp_fl = fl;
279                 fl = fl->next;
280                 kfree(tmp_fl);
281         }
282         ret = nrparts;
283         *pparts = parts;
284  out:
285         while (fl) {
286                 struct fis_list *old = fl;
287                 fl = fl->next;
288                 kfree(old);
289         }
290         vfree(buf);
291         return ret;
292 }
293
294 static struct mtd_part_parser redboot_parser = {
295         .owner = THIS_MODULE,
296         .parse_fn = parse_redboot_partitions,
297         .name = "RedBoot",
298 };
299
300 static int __init redboot_parser_init(void)
301 {
302         return register_mtd_parser(&redboot_parser);
303 }
304
305 static void __exit redboot_parser_exit(void)
306 {
307         deregister_mtd_parser(&redboot_parser);
308 }
309
310 module_init(redboot_parser_init);
311 module_exit(redboot_parser_exit);
312
313 MODULE_LICENSE("GPL");
314 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
315 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");