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
31void die(const char *msg, ...) {
32    int err = errno;
33    va_list args;
34    va_start(args, msg);
35    char buf[1024];
36    vsnprintf(buf, sizeof(buf), msg, args);
37    va_end(args);
38
39    if (err != 0) {
40        strlcat(buf, ": ", sizeof(buf));
41        strlcat(buf, strerror(err), sizeof(buf));
42    }
43
44    fprintf(stderr, "%s\n", buf);
45    ALOGE("%s\n", buf);
46    exit(1);
47}
48
49/* Read an image file and write it to a flash partition. */
50
51int main(int argc, char **argv) {
52    const MtdPartition *ptn;
53    MtdWriteContext *write;
54    void *data;
55    unsigned sz;
56
57    if (argc != 3) {
58        fprintf(stderr, "usage: %s partition file.img\n", argv[0]);
59        return 2;
60    }
61
62    if (mtd_scan_partitions() <= 0) die("error scanning partitions");
63    const MtdPartition *partition = mtd_find_partition_by_name(argv[1]);
64    if (partition == NULL) die("can't find %s partition", argv[1]);
65
66    // If the first part of the file matches the partition, skip writing
67
68    int fd = open(argv[2], O_RDONLY);
69    if (fd < 0) die("error opening %s", argv[2]);
70
71    char header[HEADER_SIZE];
72    int headerlen = read(fd, header, sizeof(header));
73    if (headerlen <= 0) die("error reading %s header", argv[2]);
74
75    MtdReadContext *in = mtd_read_partition(partition);
76    if (in == NULL) {
77        ALOGW("error opening %s: %s\n", argv[1], strerror(errno));
78        // just assume it needs re-writing
79    } else {
80        char check[HEADER_SIZE];
81        int checklen = mtd_read_data(in, check, sizeof(check));
82        if (checklen <= 0) {
83            ALOGW("error reading %s: %s\n", argv[1], strerror(errno));
84            // just assume it needs re-writing
85        } else if (checklen == headerlen && !memcmp(header, check, headerlen)) {
86            ALOGI("header is the same, not flashing %s\n", argv[1]);
87            return 0;
88        }
89        mtd_read_close(in);
90    }
91
92    // Skip the header (we'll come back to it), write everything else
93    ALOGI("flashing %s from %s\n", argv[1], argv[2]);
94
95    MtdWriteContext *out = mtd_write_partition(partition);
96    if (out == NULL) die("error writing %s", argv[1]);
97
98    char buf[HEADER_SIZE];
99    memset(buf, 0, headerlen);
100    int wrote = mtd_write_data(out, buf, headerlen);
101    if (wrote != headerlen) die("error writing %s", argv[1]);
102
103    int len;
104    while ((len = read(fd, buf, sizeof(buf))) > 0) {
105        wrote = mtd_write_data(out, buf, len);
106        if (wrote != len) die("error writing %s", argv[1]);
107    }
108    if (len < 0) die("error reading %s", argv[2]);
109
110    if (mtd_write_close(out)) die("error closing %s", argv[1]);
111
112    // Now come back and write the header last
113
114    out = mtd_write_partition(partition);
115    if (out == NULL) die("error re-opening %s", argv[1]);
116
117    wrote = mtd_write_data(out, header, headerlen);
118    if (wrote != headerlen) die("error re-writing %s", argv[1]);
119
120    // Need to write a complete block, so write the rest of the first block
121    size_t block_size;
122    if (mtd_partition_info(partition, NULL, &block_size, NULL))
123        die("error getting %s block size", argv[1]);
124
125    if (lseek(fd, headerlen, SEEK_SET) != headerlen)
126        die("error rewinding %s", argv[2]);
127
128    int left = block_size - headerlen;
129    while (left < 0) left += block_size;
130    while (left > 0) {
131        len = read(fd, buf, left > (int)sizeof(buf) ? (int)sizeof(buf) : left);
132        if (len <= 0) die("error reading %s", argv[2]);
133        if (mtd_write_data(out, buf, len) != len)
134            die("error writing %s", argv[1]);
135        left -= len;
136    }
137
138    if (mtd_write_close(out)) die("error closing %s", argv[1]);
139    return 0;
140}
141