xref: /OK3568_Linux_fs/external/recovery/mtdutils/flash_image.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23 
24 #include "cutils/log.h"
25 #include "mtdutils.h"
26 
27 #define LOG_TAG "flash_image"
28 
29 #define HEADER_SIZE 2048  // size of header to compare for equality
30 
die(const char * msg,...)31 void die(const char *msg, ...)
32 {
33     int err = errno;
34     va_list args;
35     va_start(args, msg);
36     char buf[1024];
37     vsnprintf(buf, sizeof(buf), msg, args);
38     va_end(args);
39 
40     if (err != 0) {
41         strlcat(buf, ": ", sizeof(buf));
42         strlcat(buf, strerror(err), sizeof(buf));
43     }
44 
45     fprintf(stderr, "%s\n", buf);
46     LOGE("%s\n", buf);
47     exit(1);
48 }
49 
50 /* Read an image file and write it to a flash partition. */
51 
main(int argc,char ** argv)52 int main(int argc, char **argv)
53 {
54     const MtdPartition *ptn;
55     MtdWriteContext *write;
56     void *data;
57     unsigned sz;
58 
59     if (argc != 3) {
60         fprintf(stderr, "usage: %s partition file.img\n", argv[0]);
61         return 2;
62     }
63 
64     if (mtd_scan_partitions() <= 0) die("error scanning partitions");
65     const MtdPartition *partition = mtd_find_partition_by_name(argv[1]);
66     if (partition == NULL) die("can't find %s partition", argv[1]);
67 
68     // If the first part of the file matches the partition, skip writing
69 
70     int fd = open(argv[2], O_RDONLY);
71     if (fd < 0) die("error opening %s", argv[2]);
72 
73     char header[HEADER_SIZE];
74     int headerlen = read(fd, header, sizeof(header));
75     if (headerlen <= 0) die("error reading %s header", argv[2]);
76 
77     MtdReadContext *in = mtd_read_partition(partition);
78     if (in == NULL) {
79         LOGW("error opening %s: %s\n", argv[1], strerror(errno));
80         // just assume it needs re-writing
81     } else {
82         char check[HEADER_SIZE];
83         int checklen = mtd_read_data(in, check, sizeof(check));
84         if (checklen <= 0) {
85             LOGW("error reading %s: %s\n", argv[1], strerror(errno));
86             // just assume it needs re-writing
87         } else if (checklen == headerlen && !memcmp(header, check, headerlen)) {
88             LOGI("header is the same, not flashing %s\n", argv[1]);
89             return 0;
90         }
91         mtd_read_close(in);
92     }
93 
94     // Skip the header (we'll come back to it), write everything else
95     LOGI("flashing %s from %s\n", argv[1], argv[2]);
96 
97     MtdWriteContext *out = mtd_write_partition(partition);
98     if (out == NULL) die("error writing %s", argv[1]);
99 
100     char buf[HEADER_SIZE];
101     memset(buf, 0, headerlen);
102     int wrote = mtd_write_data(out, buf, headerlen);
103     if (wrote != headerlen) die("error writing %s", argv[1]);
104 
105     int len;
106     while ((len = read(fd, buf, sizeof(buf))) > 0) {
107         wrote = mtd_write_data(out, buf, len);
108         if (wrote != len) die("error writing %s", argv[1]);
109     }
110     if (len < 0) die("error reading %s", argv[2]);
111 
112     if (mtd_write_close(out)) die("error closing %s", argv[1]);
113 
114     // Now come back and write the header last
115 
116     out = mtd_write_partition(partition);
117     if (out == NULL) die("error re-opening %s", argv[1]);
118 
119     wrote = mtd_write_data(out, header, headerlen);
120     if (wrote != headerlen) die("error re-writing %s", argv[1]);
121 
122     // Need to write a complete block, so write the rest of the first block
123     size_t block_size;
124     if (mtd_partition_info(partition, NULL, &block_size, NULL))
125         die("error getting %s block size", argv[1]);
126 
127     if (lseek(fd, headerlen, SEEK_SET) != headerlen)
128         die("error rewinding %s", argv[2]);
129 
130     int left = block_size - headerlen;
131     while (left < 0) left += block_size;
132     while (left > 0) {
133         len = read(fd, buf, left > (int)sizeof(buf) ? (int)sizeof(buf) : left);
134         if (len <= 0) die("error reading %s", argv[2]);
135         if (mtd_write_data(out, buf, len) != len)
136             die("error writing %s", argv[1]);
137         left -= len;
138     }
139 
140     if (mtd_write_close(out)) die("error closing %s", argv[1]);
141     return 0;
142 }
143