5b58523e4d4ecd597c8d72e63ae702a7b5d02389
[linux-2.6.git] / drivers / mtd / redboot.c
1 /*
2  * $Id: redboot.c,v 1.21 2006/03/30 18:34:37 bjd 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     uint32_t      flash_base;    // Address within FLASH of image
19     uint32_t      mem_base;      // Address in memory where it executes
20     uint32_t      size;          // Length of image
21     uint32_t      entry_point;   // Execution entry point
22     uint32_t      data_length;   // Length of actual data
23     unsigned char _pad[256-(16+7*sizeof(uint32_t))];
24     uint32_t      desc_cksum;    // Checksum over image descriptor
25     uint32_t      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 (!memcmp(buf[i].name, "FIS directory", 14)) {
89                         /* This is apparently the FIS directory entry for the
90                          * FIS directory itself.  The FIS directory size is
91                          * one erase block; if the buf[i].size field is
92                          * swab32(erasesize) then we know we are looking at
93                          * a byte swapped FIS directory - swap all the entries!
94                          * (NOTE: this is 'size' not 'data_length'; size is
95                          * the full size of the entry.)
96                          */
97                         if (swab32(buf[i].size) == master->erasesize) {
98                                 int j;
99                                 for (j = 0; j < numslots && buf[j].name[0] != 0xff; ++j) {
100                                         /* The unsigned long fields were written with the
101                                          * wrong byte sex, name and pad have no byte sex.
102                                          */
103                                         swab32s(&buf[j].flash_base);
104                                         swab32s(&buf[j].mem_base);
105                                         swab32s(&buf[j].size);
106                                         swab32s(&buf[j].entry_point);
107                                         swab32s(&buf[j].data_length);
108                                         swab32s(&buf[j].desc_cksum);
109                                         swab32s(&buf[j].file_cksum);
110                                 }
111                         }
112                         break;
113                 }
114         }
115         if (i == numslots) {
116                 /* Didn't find it */
117                 printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
118                        master->name);
119                 ret = 0;
120                 goto out;
121         }
122
123         for (i = 0; i < numslots; i++) {
124                 struct fis_list *new_fl, **prev;
125
126                 if (buf[i].name[0] == 0xff)
127                         continue;
128                 if (!redboot_checksum(&buf[i]))
129                         break;
130
131                 new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
132                 namelen += strlen(buf[i].name)+1;
133                 if (!new_fl) {
134                         ret = -ENOMEM;
135                         goto out;
136                 }
137                 new_fl->img = &buf[i];
138                 if (fis_origin) {
139                         buf[i].flash_base -= fis_origin;
140                 } else {
141                         buf[i].flash_base &= master->size-1;
142                 }
143
144                 /* I'm sure the JFFS2 code has done me permanent damage.
145                  * I now think the following is _normal_
146                  */
147                 prev = &fl;
148                 while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
149                         prev = &(*prev)->next;
150                 new_fl->next = *prev;
151                 *prev = new_fl;
152
153                 nrparts++;
154         }
155 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
156         if (fl->img->flash_base) {
157                 nrparts++;
158                 nulllen = sizeof(nullstring);
159         }
160
161         for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
162                 if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
163                         nrparts++;
164                         nulllen = sizeof(nullstring);
165                 }
166         }
167 #endif
168         parts = kmalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
169
170         if (!parts) {
171                 ret = -ENOMEM;
172                 goto out;
173         }
174
175         memset(parts, 0, sizeof(*parts)*nrparts + nulllen + namelen);
176
177         nullname = (char *)&parts[nrparts];
178 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
179         if (nulllen > 0) {
180                 strcpy(nullname, nullstring);
181         }
182 #endif
183         names = nullname + nulllen;
184
185         i=0;
186
187 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
188         if (fl->img->flash_base) {
189                parts[0].name = nullname;
190                parts[0].size = fl->img->flash_base;
191                parts[0].offset = 0;
192                 i++;
193         }
194 #endif
195         for ( ; i<nrparts; i++) {
196                 parts[i].size = fl->img->size;
197                 parts[i].offset = fl->img->flash_base;
198                 parts[i].name = names;
199
200                 strcpy(names, fl->img->name);
201 #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
202                 if (!memcmp(names, "RedBoot", 8) ||
203                                 !memcmp(names, "RedBoot config", 15) ||
204                                 !memcmp(names, "FIS directory", 14)) {
205                         parts[i].mask_flags = MTD_WRITEABLE;
206                 }
207 #endif
208                 names += strlen(names)+1;
209
210 #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
211                 if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
212                         i++;
213                         parts[i].offset = parts[i-1].size + parts[i-1].offset;
214                         parts[i].size = fl->next->img->flash_base - parts[i].offset;
215                         parts[i].name = nullname;
216                 }
217 #endif
218                 tmp_fl = fl;
219                 fl = fl->next;
220                 kfree(tmp_fl);
221         }
222         ret = nrparts;
223         *pparts = parts;
224  out:
225         while (fl) {
226                 struct fis_list *old = fl;
227                 fl = fl->next;
228                 kfree(old);
229         }
230         vfree(buf);
231         return ret;
232 }
233
234 static struct mtd_part_parser redboot_parser = {
235         .owner = THIS_MODULE,
236         .parse_fn = parse_redboot_partitions,
237         .name = "RedBoot",
238 };
239
240 static int __init redboot_parser_init(void)
241 {
242         return register_mtd_parser(&redboot_parser);
243 }
244
245 static void __exit redboot_parser_exit(void)
246 {
247         deregister_mtd_parser(&redboot_parser);
248 }
249
250 module_init(redboot_parser_init);
251 module_exit(redboot_parser_exit);
252
253 MODULE_LICENSE("GPL");
254 MODULE_AUTHOR("Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>");
255 MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");