Pull mca-cleanup into release branch
[linux-2.6] / drivers / mtd / redboot.c
1 /*
2  * $Id: redboot.c,v 1.19 2005/12/01 10:03:51 dwmw2 Exp $
3  *
4  * Parse RedBoot-style Flash Image System (FIS) tables and
5  * produce a Linux partition array to match.
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
10 #include <linux/init.h>
11 #include <linux/vmalloc.h>
12
13 #include <linux/mtd/mtd.h>
14 #include <linux/mtd/partitions.h>
15
16 struct fis_image_desc {
17     unsigned char name[16];      // Null terminated name
18     unsigned long flash_base;    // Address within FLASH of image
19     unsigned long mem_base;      // Address in memory where it executes
20     unsigned long size;          // Length of image
21     unsigned long entry_point;   // Execution entry point
22     unsigned long data_length;   // Length of actual data
23     unsigned char _pad[256-(16+7*sizeof(unsigned long))];
24     unsigned long desc_cksum;    // Checksum over image descriptor
25     unsigned long file_cksum;    // Checksum over image data
26 };
27
28 struct fis_list {
29         struct fis_image_desc *img;
30         struct fis_list *next;
31 };
32
33 static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
34 module_param(directory, int, 0);
35
36 static inline int redboot_checksum(struct fis_image_desc *img)
37 {
38         /* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
39         return 1;
40 }
41
42 static int parse_redboot_partitions(struct mtd_info *master,
43                              struct mtd_partition **pparts,
44                              unsigned long fis_origin)
45 {
46         int nrparts = 0;
47         struct fis_image_desc *buf;
48         struct mtd_partition *parts;
49         struct fis_list *fl = NULL, *tmp_fl;
50         int ret, i;
51         size_t retlen;
52         char *names;
53         char *nullname;
54         int namelen = 0;
55         int nulllen = 0;
56         int numslots;
57         unsigned long offset;
58 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
59         static char nullstring[] = "unallocated";
60 #endif
61
62         buf = vmalloc(master->erasesize);
63
64         if (!buf)
65                 return -ENOMEM;
66
67         if ( directory < 0 )
68                 offset = master->size + directory*master->erasesize;
69         else
70                 offset = directory*master->erasesize;
71
72         printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
73                master->name, offset);
74
75         ret = master->read(master, offset,
76                            master->erasesize, &retlen, (void *)buf);
77
78         if (ret)
79                 goto out;
80
81         if (retlen != master->erasesize) {
82                 ret = -EIO;
83                 goto out;
84         }
85
86         numslots = (master->erasesize / sizeof(struct fis_image_desc));
87         for (i = 0; i < numslots; i++) {
88                 if (buf[i].name[0] == 0xff) {
89                         i = numslots;
90                         break;
91                 }
92                 if (!memcmp(buf[i].name, "FIS directory", 14)) {
93                         /* This is apparently the FIS directory entry for the
94                          * FIS directory itself.  The FIS directory size is
95                          * one erase block; if the buf[i].size field is
96                          * swab32(erasesize) then we know we are looking at
97                          * a byte swapped FIS directory - swap all the entries!
98                          * (NOTE: this is 'size' not 'data_length'; size is
99                          * the full size of the entry.)
100                          */
101                         if (swab32(buf[i].size) == master->erasesize) {
102                                 int j;
103                                 for (j = 0; j < numslots && buf[j].name[0] != 0xff; ++j) {
104                                         /* The unsigned long fields were written with the
105                                          * wrong byte sex, name and pad have no byte sex.
106                                          */
107                                         swab32s(&buf[j].flash_base);
108                                         swab32s(&buf[j].mem_base);
109                                         swab32s(&buf[j].size);
110                                         swab32s(&buf[j].entry_point);
111                                         swab32s(&buf[j].data_length);
112                                         swab32s(&buf[j].desc_cksum);
113                                         swab32s(&buf[j].file_cksum);
114                                 }
115                         }
116                         break;
117                 }
118         }
119         if (i == numslots) {
120                 /* Didn't find it */
121                 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
122                        master->name);
123                 ret = 0;
124                 goto out;
125         }
126
127         for (i = 0; i < numslots; i++) {
128                 struct fis_list *new_fl, **prev;
129
130                 if (buf[i].name[0] == 0xff)
131                         break;
132                 if (!redboot_checksum(&buf[i]))
133                         break;
134
135                 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
136                 namelen += strlen(buf[i].name)+1;
137                 if (!new_fl) {
138                         ret = -ENOMEM;
139                         goto out;
140                 }
141                 new_fl->img = &buf[i];
142                 if (fis_origin) {
143                         buf[i].flash_base -= fis_origin;
144                 } else {
145                         buf[i].flash_base &= master->size-1;
146                 }
147
148                 /* I'm sure the JFFS2 code has done me permanent damage.
149                  * I now think the following is _normal_
150                  */
151                 prev = &fl;
152                 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
153                         prev = &(*prev)->next;
154                 new_fl->next = *prev;
155                 *prev = new_fl;
156
157                 nrparts++;
158         }
159 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
160         if (fl->img->flash_base) {
161                 nrparts++;
162                 nulllen = sizeof(nullstring);
163         }
164
165         for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
166                 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
167                         nrparts++;
168                         nulllen = sizeof(nullstring);
169                 }
170         }
171 #endif
172         parts = kmalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
173
174         if (!parts) {
175                 ret = -ENOMEM;
176                 goto out;
177         }
178
179         memset(parts, 0, sizeof(*parts)*nrparts + nulllen + namelen);
180
181         nullname = (char *)&parts[nrparts];
182 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
183         if (nulllen > 0) {
184                 strcpy(nullname, nullstring);
185         }
186 #endif
187         names = nullname + nulllen;
188
189         i=0;
190
191 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
192         if (fl->img->flash_base) {
193                parts[0].name = nullname;
194                parts[0].size = fl->img->flash_base;
195                parts[0].offset = 0;
196                 i++;
197         }
198 #endif
199         for ( ; i<nrparts; i++) {
200                 parts[i].size = fl->img->size;
201                 parts[i].offset = fl->img->flash_base;
202                 parts[i].name = names;
203
204                 strcpy(names, fl->img->name);
205 #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
206                 if (!memcmp(names, "RedBoot", 8) ||
207                                 !memcmp(names, "RedBoot config", 15) ||
208                                 !memcmp(names, "FIS directory", 14)) {
209                         parts[i].mask_flags = MTD_WRITEABLE;
210                 }
211 #endif
212                 names += strlen(names)+1;
213
214 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
215                 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
216                         i++;
217                         parts[i].offset = parts[i-1].size + parts[i-1].offset;
218                         parts[i].size = fl->next->img->flash_base - parts[i].offset;
219                         parts[i].name = nullname;
220                 }
221 #endif
222                 tmp_fl = fl;
223                 fl = fl->next;
224                 kfree(tmp_fl);
225         }
226         ret = nrparts;
227         *pparts = parts;
228  out:
229         while (fl) {
230                 struct fis_list *old = fl;
231                 fl = fl->next;
232                 kfree(old);
233         }
234         vfree(buf);
235         return ret;
236 }
237
238 static struct mtd_part_parser redboot_parser = {
239         .owner = THIS_MODULE,
240         .parse_fn = parse_redboot_partitions,
241         .name = "RedBoot",
242 };
243
244 static int __init redboot_parser_init(void)
245 {
246         return register_mtd_parser(&redboot_parser);
247 }
248
249 static void __exit redboot_parser_exit(void)
250 {
251         deregister_mtd_parser(&redboot_parser);
252 }
253
254 module_init(redboot_parser_init);
255 module_exit(redboot_parser_exit);
256
257 MODULE_LICENSE("GPL");
258 MODULE_AUTHOR("Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>");
259 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");