1/*
2 * Copyright (C) 2016 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 <stdio.h>
18#include <stdlib.h>
19
20#include "libfdt.h"
21#include "libufdt_sysdeps.h"
22
23#include "util.h"
24
25
26int find_dtb_header_pos(const char *buf, size_t buf_size) {
27  if (buf == NULL || buf_size == 0) {
28    return -1;
29  }
30
31  int pos = buf_size;
32  while (1) {
33    pos--;
34    if (pos < 0) {
35      break;
36    }
37    uint32_t tag = fdt32_to_cpu(*(fdt32_t *)(buf + pos));
38    if (tag == FDT_MAGIC) {
39      // Hit!
40      break;
41    }
42  }
43
44  return pos;
45}
46
47int find_and_write_dtb(const char *filename,
48                       const char *buf, size_t buf_size) {
49  int tag_pos = find_dtb_header_pos(buf, buf_size);
50  if (tag_pos < 0) {
51    goto end;
52  }
53
54  // Check FDT header
55  const char *fdt_ptr = buf + tag_pos;
56  if (fdt_check_header(fdt_ptr) != 0) {
57    fprintf(stderr, "Bad DTB header.\n");
58    goto end;
59  }
60
61  // Check FDT size and actual size
62  size_t fdt_size = fdt_totalsize(fdt_ptr);
63  size_t fdt_actual_size = buf_size - tag_pos;
64  int fdt_size_diff = (int)fdt_actual_size - (int)fdt_size;
65  if (fdt_size_diff) {
66    fprintf(stderr, "Wrong size: actual size = %d FDT size = %d(%d)\n",
67      fdt_actual_size, fdt_size, fdt_size_diff);
68  }
69
70  // Print the DT basic information
71  int root_node_off = fdt_path_offset(fdt_ptr, "/");
72  if (root_node_off < 0) {
73    fprintf(stderr, "Can not get the root node.\n");
74    goto end;
75  }
76  printf("Output %s\n", filename);
77  const char *model =
78    (const char *)fdt_getprop(fdt_ptr, root_node_off, "model", NULL);
79  printf("  model=%s\n", model ? model : "(unknown)");
80  const char *compatible =
81    (const char *)fdt_getprop(fdt_ptr, root_node_off, "compatible", NULL);
82  printf("  compatible=%s\n", compatible ? compatible : "(unknown)");
83
84  // Output DTB file
85  if (write_fdt_to_file(filename, fdt_ptr) != 0) {
86    fprintf(stderr, "Write file error: %s\n", filename);
87    goto end;
88  }
89
90end:
91  return tag_pos;
92}
93
94int extract_dtbs(const char *in_filename,
95                 const char *out_dtb_filename,
96                 const char *out_image_filename) {
97  int ret = 1;
98  char *buf = NULL;
99
100  size_t buf_size;
101  buf = load_file(in_filename, &buf_size);
102  if (!buf) {
103    fprintf(stderr, "Can not load file: %s\n", in_filename);
104    goto end;
105  }
106
107  char filename[128];
108  int index = 0;
109  while (buf_size > 0) {
110    int tag_pos;
111    if (index > 0) {
112      snprintf(filename, sizeof(filename), "%s.%d", out_dtb_filename, index);
113      tag_pos = find_and_write_dtb(filename, buf, buf_size);
114    } else {
115      tag_pos = find_and_write_dtb(out_dtb_filename, buf, buf_size);
116    }
117    if (tag_pos < 0) {
118      break;
119    }
120
121    buf_size = tag_pos;
122    index++;
123  }
124
125  if (index == 0) {
126    fprintf(stderr, "Can not find any DTB.\n");
127    goto end;
128  }
129
130  // Output the rest buffer as image file
131  if (out_image_filename != NULL) {
132    printf("Output %s\n", out_image_filename);
133    if (write_buf_to_file(out_image_filename, buf, buf_size) != 0) {
134      fprintf(stderr, "Write file error: %s\n", out_image_filename);
135      goto end;
136    }
137  }
138
139  ret = 0;
140
141end:
142  if (buf) dto_free(buf);
143
144  return ret;
145}
146
147int main(int argc, char **argv) {
148  if (argc < 3) {
149    fprintf(stderr, "Usage: %s <image.gz-dtb_file> <out_dtb_name> (<out_image_name>)\n\n", argv[0]);
150    fprintf(stderr, " Note: If there are more than one DTB, it outputs DTB files named\n" \
151                    "       out_dtb_name, out_dtb_name.1, out_dtb_name.2, etc.\n");
152    return 1;
153  }
154
155  const char *in_file = argv[1];
156  const char *out_dtb_file = argv[2];
157  const char *out_image_file = (argc > 3) ? argv[3] : NULL;
158  int ret = extract_dtbs(in_file, out_dtb_file, out_image_file);
159
160  return ret;
161}
162