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 26 int 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 47 int 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 90 end: 91 return tag_pos; 92 } 93 94 int 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; 140 141 end: 142 if (buf) dto_free(buf); 143 144 return ret; 145 } 146 147 int 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
