/* * This file is part of the libpayload project. * * Copyright (C) 2011 secunet Security Networks AG * Copyright (C) 2013 Google, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* The CBFS core requires a couple of #defines or functions to adapt it to the * target environment: * * CBFS_CORE_WITH_LZMA (must be #define) * if defined, ulzma() must exist for decompression of data streams * * ERROR(x...) * print an error message x (in printf format) * * LOG(x...) * print a message x (in printf format) * * DEBUG(x...) * print a debug message x (in printf format) * */ #include <cbfs.h> #include <string.h> /* returns a pointer to CBFS master header, or CBFS_HEADER_INVALID_ADDRESS * on failure */ const struct cbfs_header *cbfs_get_header(struct cbfs_media *media) { int32_t rel_offset; const struct cbfs_header *header; struct cbfs_media default_media; if (media == CBFS_DEFAULT_MEDIA) { media = &default_media; if (init_default_cbfs_media(media) != 0) { ERROR("Failed to initialize default media.\n"); return CBFS_HEADER_INVALID_ADDRESS; } } media->open(media); if (!media->read(media, &rel_offset, (size_t)(0 - sizeof(int32_t)), sizeof(int32_t))) { ERROR("Could not read CBFS master header offset!\n"); return CBFS_HEADER_INVALID_ADDRESS; } header = media->map(media, (size_t)rel_offset, sizeof(*header)); DEBUG("CBFS header at %#zx (-%#zx from end of image).\n", (size_t)rel_offset, (size_t)-rel_offset); media->close(media); if (header == CBFS_MEDIA_INVALID_MAP_ADDRESS) { ERROR("Failed to load CBFS header from %#zx(-%#zx)\n", (size_t)rel_offset, (size_t)-rel_offset); return CBFS_HEADER_INVALID_ADDRESS; } if (CBFS_HEADER_MAGIC != ntohl(header->magic)) { ERROR("Could not find valid CBFS master header at %#zx(-%#zx): " "magic %#.8x vs %#.8x.\n", (size_t)rel_offset, (size_t)-rel_offset, CBFS_HEADER_MAGIC, ntohl(header->magic)); if (header->magic == 0xffffffff) { ERROR("Maybe ROM is not mapped properly?\n"); } return CBFS_HEADER_INVALID_ADDRESS; } return header; } /* public API starts here*/ struct cbfs_file *cbfs_get_file(struct cbfs_media *media, const char *name) { const char *file_name; uint32_t offset, romsize, name_len; const struct cbfs_header *header; struct cbfs_file file, *file_ptr; struct cbfs_media default_media; if (media == CBFS_DEFAULT_MEDIA) { media = &default_media; if (init_default_cbfs_media(media) != 0) { ERROR("Failed to initialize default media.\n"); return NULL; } } if (CBFS_HEADER_INVALID_ADDRESS == (header = cbfs_get_header(media))) return NULL; // Logical offset (for source media) of first file. offset = ntohl(header->offset); romsize = ntohl(header->romsize); // TODO Add a "size" in CBFS header for a platform independent way to // determine the end of CBFS data. #if IS_ENABLED(CONFIG_LP_ARCH_X86) // resolve actual length of ROM used for CBFS components // the bootblock size was not taken into account romsize -= ntohl(header->bootblocksize); // fine tune the length to handle alignment positioning. // using (bootblock size) % align, to derive the // number of bytes the bootblock is off from the alignment size. if ((ntohl(header->bootblocksize) % CBFS_ALIGNMENT)) romsize -= (CBFS_ALIGNMENT - (ntohl(header->bootblocksize) % CBFS_ALIGNMENT)); else romsize -= 1; #endif DEBUG("CBFS location: 0x%x~0x%x\n", offset, romsize); DEBUG("Looking for '%s' starting from 0x%x.\n", name, offset); media->open(media); while (offset < romsize && media->read(media, &file, offset, sizeof(file)) == sizeof(file)) { if (memcmp(CBFS_FILE_MAGIC, file.magic, sizeof(file.magic)) != 0) { uint32_t new_align = CBFS_ALIGNMENT; if (offset % CBFS_ALIGNMENT) new_align += CBFS_ALIGNMENT - (offset % CBFS_ALIGNMENT); ERROR("ERROR: No file header found at 0x%xx - " "try next aligned address: 0x%x.\n", offset, offset + new_align); offset += new_align; continue; } name_len = ntohl(file.offset) - sizeof(file); DEBUG(" - load entry 0x%x file name (%d bytes)...\n", offset, name_len); // load file name (arbitrary length). file_name = (const char*)media->map( media, offset + sizeof(file), name_len); if (file_name == CBFS_MEDIA_INVALID_MAP_ADDRESS) { ERROR("ERROR: Failed to get filename: 0x%x.\n", offset); } else if (strcmp(file_name, name) == 0) { int file_offset = ntohl(file.offset), file_len = ntohl(file.len); DEBUG("Found file (offset=0x%x, len=%d).\n", offset + file_offset, file_len); media->unmap(media, file_name); file_ptr = media->map(media, offset, file_offset + file_len); media->close(media); return file_ptr; } else { DEBUG(" (unmatched file @0x%x: %s)\n", offset, file_name); media->unmap(media, file_name); } // Move to next file. offset += ntohl(file.len) + ntohl(file.offset); if (offset % CBFS_ALIGNMENT) offset += CBFS_ALIGNMENT - (offset % CBFS_ALIGNMENT); } media->close(media); LOG("WARNING: '%s' not found.\n", name); return NULL; } void *cbfs_get_file_content(struct cbfs_media *media, const char *name, int type, size_t *sz) { struct cbfs_file *file = cbfs_get_file(media, name); if (sz) *sz = 0; if (file == NULL) { ERROR("Could not find file '%s'.\n", name); return NULL; } if (ntohl(file->type) != type) { ERROR("File '%s' is of type %x, but we requested %x.\n", name, ntohl(file->type), type); return NULL; } if (sz) *sz = ntohl(file->len); return (void *)CBFS_SUBHEADER(file); } int cbfs_decompress(int algo, void *src, void *dst, int len) { switch (algo) { case CBFS_COMPRESS_NONE: memcpy(dst, src, len); return len; #ifdef CBFS_CORE_WITH_LZMA case CBFS_COMPRESS_LZMA: return ulzma(src, dst); #endif default: ERROR("tried to decompress %d bytes with algorithm #%x," "but that algorithm id is unsupported.\n", len, algo); return 0; } }