ROOT_DIR_OFFSET
const u32 *root_directory = &fw_parent_device(unit)->config_rom[ROOT_DIR_OFFSET];
const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]);
quirks |= detect_quirks_by_root_directory(rom + ROOT_DIR_OFFSET, length - ROOT_DIR_OFFSET);
fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]);