Function parse_microcode_blob

util/cbfstool/fit.c:267–329

}

static int
parse_microcode_blob(struct cbfs_image *image,
		     const char *blob_name,
		     size_t *mcus_found,
		     struct microcode_entry *mcus,
		     const size_t max_fit_entries)
{
	size_t num_mcus;
	uint32_t current_offset;
	uint32_t file_length;
	struct cbfs_file *mcode_file;

	mcode_file = cbfs_get_entry(image, blob_name);
	if (!mcode_file) {
		ERROR("Couldn't find microcode blob.\n");
		return 1;
	}

	fit_location_from_cbfs_header(&current_offset, &file_length,
				      mcode_file);
	current_offset += cbfs_get_entry_addr(image, mcode_file);

	num_mcus = 0;
	while (file_length > sizeof(struct microcode_header)) {
		const struct microcode_header *mcu_header;

		mcu_header = rom_buffer_pointer(&image->buffer, current_offset);
		if (!mcu_header) {
			ERROR("Couldn't parse microcode header.\n");
			return 1;
		}

		/* Newer microcode updates include a size field, whereas older
		 * containers set it at 0 and are exactly 2048 bytes long */
		uint32_t total_size = mcu_header->total_size ?: 2048;

		/* Quickly sanity check a prospective microcode update. */
		if (total_size < sizeof(*mcu_header) ||
		    total_size > file_length)
			break;

		if (num_mcus == max_fit_entries) {
			ERROR("Maximum of FIT entries reached.\n");
			return 1;
		}

		/* FIXME: Should the checksum be validated? */
		mcus[num_mcus].offset = current_offset;
		mcus[num_mcus].size = total_size;

		/* Proceed to next payload. */
		current_offset += mcus[num_mcus].size;
		file_length -= mcus[num_mcus].size;
		num_mcus++;
		if (file_length < sizeof(struct microcode_header))
			break;
	}