mtd: add support for rewriting the fis table layout on redboot based systems
[openwrt.git] / package / mtd / src / fis.c
1 #include <sys/mman.h>
2 #include <stdint.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <unistd.h>
6 #include <stdio.h>
7 #include "crc32.h"
8 #include "mtd.h"
9 #include "fis.h"
10
11 struct fis_image_hdr {
12         unsigned char name[16];
13         uint32_t flash_base;
14         uint32_t mem_base;
15         uint32_t size;
16         uint32_t entry_point;
17         uint32_t data_length;
18 } __attribute__((packed));
19
20 struct fis_image_crc {
21         uint32_t desc;
22         uint32_t file;
23 } __attribute__((packed));
24
25 struct fis_image_desc {
26         struct fis_image_hdr hdr;
27         char _pad[256 - sizeof(struct fis_image_hdr) - sizeof(struct fis_image_crc)];
28         struct fis_image_crc crc;
29 } __attribute__((packed));
30
31 static int fis_fd = -1;
32 static struct fis_image_desc *fis_desc;
33 static int fis_erasesize = 0;
34
35 static void
36 fis_close(void)
37 {
38         if (fis_desc)
39                 munmap(fis_desc, fis_erasesize);
40
41         if (fis_fd >= 0)
42                 close(fis_fd);
43
44         fis_fd = -1;
45         fis_desc = NULL;
46 }
47
48 static struct fis_image_desc *
49 fis_open(void)
50 {
51         struct fis_image_desc *desc;
52
53         if (fis_fd >= 0)
54                 fis_close();
55
56         fis_fd = mtd_check_open("FIS directory");
57         if (fis_fd < 0)
58                 goto error;
59
60         close(fis_fd);
61         fis_fd = mtd_open("FIS directory", true);
62         if (fis_fd < 0)
63                 goto error;
64
65         fis_erasesize = erasesize;
66         desc = mmap(NULL, erasesize, PROT_READ|PROT_WRITE, MAP_SHARED, fis_fd, 0);
67         if (desc == MAP_FAILED)
68                 goto error;
69
70         fis_desc = desc;
71         return desc;
72
73 error:
74         fis_close();
75         return NULL;
76 }
77
78 int
79 fis_validate(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
80 {
81         struct fis_image_desc *desc;
82         void *end;
83         int found = 0;
84         int i;
85
86         desc = fis_open();
87         if (!desc)
88                 return 0;
89
90         for (i = 0; i < n_new - 1; i++) {
91                 if (!new[i].size) {
92                         fprintf(stderr, "FIS error: only the last partition can detect the size automatically\n");
93                         i = -1;
94                         goto done;
95                 }
96         }
97
98         end = desc;
99         end = (char *) end + fis_erasesize;
100         while ((void *) desc < end) {
101                 if (!desc->hdr.name[0] || (desc->hdr.name[0] == 0xff))
102                         break;
103
104                 for (i = 0; i < n_old; i++) {
105                         if (!strncmp((char *) desc->hdr.name, (char *) old[i].name, sizeof(desc->hdr.name))) {
106                                 found++;
107                                 goto next;
108                         }
109                 }
110 next:
111                 desc++;
112                 continue;
113         }
114
115         if (found == n_old)
116                 i = 1;
117         else
118                 i = -1;
119
120 done:
121         fis_close();
122         return i;
123 }
124
125 int
126 fis_remap(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
127 {
128         struct fis_image_desc *fisdir = NULL;
129         struct fis_image_desc *redboot = NULL;
130         struct fis_image_desc *first = NULL;
131         struct fis_image_desc *last = NULL;
132         struct fis_image_desc *desc;
133         struct fis_part *part;
134         uint32_t offset = 0, size = 0;
135         char *end, *tmp;
136         int i;
137
138         desc = fis_open();
139         if (!desc)
140                 return -1;
141
142         if (!quiet)
143                 fprintf(stderr, "Updating FIS table... \n");
144
145         end = (char *) desc + fis_erasesize;
146         while ((char *) desc < end) {
147                 if (!desc->hdr.name[0] || (desc->hdr.name[0] == 0xff))
148                         break;
149
150                 if (!strcmp((char *) desc->hdr.name, "FIS directory"))
151                         fisdir = desc;
152
153                 if (!strcmp((char *) desc->hdr.name, "RedBoot"))
154                         redboot = desc;
155
156                 for (i = 0; i < n_old; i++) {
157                         if (!strncmp((char *) desc->hdr.name, (char *) old[i].name, sizeof(desc->hdr.name))) {
158                                 size += desc->hdr.size;
159                                 last = desc;
160                                 if (!first)
161                                         first = desc;
162                                 break;
163                         }
164                 }
165                 desc++;
166         }
167         desc--;
168
169         if (desc == last) {
170                 desc = fisdir;
171         }
172
173         /* size fixup */
174         if (desc && (last->hdr.flash_base < desc->hdr.flash_base - last->hdr.size))
175                         size += (desc->hdr.flash_base - last->hdr.flash_base) - last->hdr.size;
176
177 #ifdef notyet
178         desc = first - 1;
179         if (redboot && (desc >= redboot)) {
180                 if (first->hdr.flash_base - desc->hdr.size > desc->hdr.flash_base) {
181                         int delta = first->hdr.flash_base - desc->hdr.size - desc->hdr.flash_base;
182
183                         offset -= delta;
184                         size += delta;
185                 }
186         }
187 #endif
188
189         last++;
190         desc = first + n_new;
191         offset = first->hdr.flash_base;
192
193         if (desc != last) {
194                 if (desc > last)
195                         tmp = (char *) desc;
196                 else
197                         tmp = (char *) last;
198
199                 memmove(desc, last, end - tmp);
200                 if (desc < last) {
201                         tmp = end - (last - desc) * sizeof(struct fis_image_desc);
202                         memset(tmp, 0xff, tmp - end);
203                 }
204         }
205
206         for (part = new, desc = first; desc < first + n_new; desc++, part++) {
207                 memset(desc, 0, sizeof(struct fis_image_desc));
208                 memcpy(desc->hdr.name, part->name, sizeof(desc->hdr.name));
209                 desc->crc.desc = 0;
210                 desc->crc.file = 0;
211
212                 desc->hdr.flash_base = offset;
213                 desc->hdr.mem_base = part->loadaddr;
214                 desc->hdr.entry_point = part->loadaddr;
215                 desc->hdr.size = (part->size > 0) ? part->size : size;
216                 desc->hdr.data_length = desc->hdr.size;
217
218                 offset += desc->hdr.size;
219                 size -= desc->hdr.size;
220         }
221
222         msync(fis_desc, fis_erasesize, MS_SYNC|MS_INVALIDATE);
223         fis_close();
224
225         return 0;
226 }