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");
260
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