Hung-Te Lin | eab2c81 | 2013-01-29 01:56:17 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * CBFS Image Manipulation |
| 3 | * |
| 4 | * Copyright (C) 2013 The Chromium OS Authors. All rights reserved. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; version 2 of the License. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA |
| 18 | */ |
| 19 | |
| 20 | #include <stdio.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <string.h> |
| 23 | |
| 24 | #include "common.h" |
| 25 | #include "cbfs_image.h" |
| 26 | |
| 27 | /* The file name align is not defined in CBFS spec -- only a preference by |
| 28 | * (old) cbfstool. */ |
| 29 | #define CBFS_FILENAME_ALIGN (16) |
| 30 | |
| 31 | /* To make CBFS more friendly to ROM, fill -1 (0xFF) instead of zero. */ |
| 32 | #define CBFS_CONTENT_DEFAULT_VALUE (-1) |
| 33 | |
| 34 | static uint32_t align_up(uint32_t value, uint32_t align) { |
| 35 | if (value % align) |
| 36 | value += align - (value % align); |
| 37 | return value; |
| 38 | } |
| 39 | |
| 40 | int cbfs_image_from_file(struct cbfs_image *image, const char *filename) { |
| 41 | if (buffer_from_file(&image->buffer, filename) != 0) |
| 42 | return -1; |
| 43 | DEBUG("read_cbfs_image: %s (%zd bytes)\n", image->buffer.name, |
| 44 | image->buffer.size); |
| 45 | image->header = cbfs_find_header(image->buffer.data, |
| 46 | image->buffer.size); |
| 47 | if (!image->header) { |
| 48 | ERROR("%s does not have CBFS master header.\n", filename); |
| 49 | cbfs_image_delete(image); |
| 50 | return -1; |
| 51 | } |
| 52 | |
| 53 | return 0; |
| 54 | } |
| 55 | |
| 56 | int cbfs_image_write_file(struct cbfs_image *image, const char *filename) { |
| 57 | assert(image && image->buffer.data); |
| 58 | return buffer_write_file(&image->buffer, filename); |
| 59 | } |
| 60 | |
| 61 | int cbfs_image_delete(struct cbfs_image *image) { |
| 62 | buffer_delete(&image->buffer); |
| 63 | image->header = NULL; |
| 64 | return 0; |
| 65 | } |
| 66 | |
| 67 | struct cbfs_header *cbfs_find_header(char *data, size_t size) { |
| 68 | size_t offset; |
| 69 | int found = 0; |
| 70 | uint32_t x86sig; |
| 71 | struct cbfs_header *header, *result = NULL; |
| 72 | |
| 73 | // Try x86 style (check signature in bottom) header first. |
| 74 | x86sig = *(uint32_t *)(data + size - sizeof(uint32_t)); |
| 75 | offset = (x86sig + (uint32_t)size); |
| 76 | DEBUG("x86sig: 0x%x, offset: 0x%zx\n", x86sig, offset); |
| 77 | if (offset >= size - sizeof(*header) || |
| 78 | ntohl(((struct cbfs_header *)(data + offset))->magic) != |
| 79 | CBFS_HEADER_MAGIC) |
| 80 | offset = 0; |
| 81 | |
| 82 | for (; offset + sizeof(*header) < size; offset++) { |
| 83 | header = (struct cbfs_header *)(data + offset); |
| 84 | if (ntohl(header->magic) !=(CBFS_HEADER_MAGIC)) |
| 85 | continue; |
| 86 | if (ntohl(header->version) != CBFS_HEADER_VERSION1 && |
| 87 | ntohl(header->version) != CBFS_HEADER_VERSION2) { |
| 88 | // Probably not a real CBFS header? |
| 89 | continue; |
| 90 | } |
| 91 | found++; |
| 92 | result = header; |
| 93 | } |
| 94 | if (found > 1) { |
| 95 | ERROR("multiple (%d) CBFS headers found!\n", |
| 96 | found); |
| 97 | result = NULL; |
| 98 | } |
| 99 | return result; |
| 100 | } |
| 101 | |
| 102 | |
| 103 | struct cbfs_file *cbfs_find_first_entry(struct cbfs_image *image) { |
| 104 | assert(image && image->header); |
| 105 | return (struct cbfs_file *)(image->buffer.data + |
| 106 | ntohl(image->header->offset)); |
| 107 | } |
| 108 | |
| 109 | struct cbfs_file *cbfs_find_next_entry(struct cbfs_image *image, |
| 110 | struct cbfs_file *entry) { |
| 111 | uint32_t addr = cbfs_get_entry_addr(image, entry); |
| 112 | int align = ntohl(image->header->align); |
| 113 | assert(entry && cbfs_is_valid_entry(entry)); |
| 114 | addr += ntohl(entry->offset) + ntohl(entry->len); |
| 115 | addr = align_up(addr, align); |
| 116 | return (struct cbfs_file *)(image->buffer.data + addr); |
| 117 | } |
| 118 | |
| 119 | uint32_t cbfs_get_entry_addr(struct cbfs_image *image, struct cbfs_file *entry) { |
| 120 | assert(image && image->buffer.data && entry); |
| 121 | return (int32_t)((char *)entry - image->buffer.data); |
| 122 | } |
| 123 | |
| 124 | int cbfs_is_valid_entry(struct cbfs_file *entry) { |
| 125 | return (entry &&memcmp(entry->magic, CBFS_FILE_MAGIC, |
| 126 | sizeof(entry->magic)) == 0); |
| 127 | } |
| 128 | |