Commit 7fffa694 authored by Simon Arlott's avatar Simon Arlott Committed by Brian Norris
Browse files

mtd: bcm63xxpart: Extract read of image tag to separate function 



Extract image tag reading and CRC check to a separate function.

Signed-off-by: default avatarSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent 436e94a6

drivers/mtd/bcm63xxpart.c

+40 −22
Original line number Diff line number Diff line
@@ -41,6 +41,10 @@ 
#define BCM963XX_CFE_VERSION_OFFSET	0x570

#define BCM963XX_NVRAM_OFFSET		0x580



/* Ensure strings read from flash structs are null terminated */

#define STR_NULL_TERMINATE(x) \

	do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)



static int bcm63xx_detect_cfe(struct mtd_info *master)

{

	char buf[9];
@@ -89,6 +93,37 @@ static int bcm63xx_read_nvram(struct mtd_info *master, 
	return 0;

}



static int bcm63xx_read_image_tag(struct mtd_info *master, const char *name,

	loff_t tag_offset, struct bcm_tag *buf)

{

	int ret;

	size_t retlen;

	u32 computed_crc;



	ret = mtd_read(master, tag_offset, sizeof(*buf), &retlen, (void *)buf);

	if (ret)

		return ret;



	if (retlen != sizeof(*buf))

		return -EIO;



	computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,

				offsetof(struct bcm_tag, header_crc));

	if (computed_crc == buf->header_crc) {

		STR_NULL_TERMINATE(buf->board_id);

		STR_NULL_TERMINATE(buf->tag_version);



		pr_info("%s: CFE image tag found at 0x%llx with version %s, board type %s\n",

			name, tag_offset, buf->tag_version, buf->board_id);



		return 0;

	}



	pr_warn("%s: CFE image tag at 0x%llx CRC invalid (expected %08x, actual %08x)\n",

		name, tag_offset, buf->header_crc, computed_crc);

	return 1;

}



static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,

					const struct mtd_partition **pparts,

					struct mtd_part_parser_data *data)
@@ -99,13 +134,11 @@ static int bcm63xx_parse_cfe_partitions(struct mtd_info *master, 
	struct bcm_tag *buf = NULL;

	struct mtd_partition *parts;

	int ret;

	size_t retlen;

	unsigned int rootfsaddr, kerneladdr, spareaddr;

	unsigned int rootfslen, kernellen, sparelen, totallen;

	unsigned int cfelen, nvramlen;

	unsigned int cfe_erasesize;

	int i;

	u32 computed_crc;

	bool rootfs_first = false;



	if (bcm63xx_detect_cfe(master))
@@ -134,28 +167,13 @@ static int bcm63xx_parse_cfe_partitions(struct mtd_info *master, 
	}



	/* Get the tag */

	ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,

		       (void *)buf);



	if (retlen != sizeof(struct bcm_tag)) {

		ret = -EIO;

		goto out;

	}



	computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,

				offsetof(struct bcm_tag, header_crc));

	if (computed_crc == buf->header_crc) {

		char *boardid = &(buf->board_id[0]);

		char *tagversion = &(buf->tag_version[0]);



	ret = bcm63xx_read_image_tag(master, "rootfs", cfelen, buf);

	if (!ret) {

		sscanf(buf->flash_image_start, "%u", &rootfsaddr);

		sscanf(buf->kernel_address, "%u", &kerneladdr);

		sscanf(buf->kernel_length, "%u", &kernellen);

		sscanf(buf->total_length, "%u", &totallen);



		pr_info("CFE boot tag found with version %s and board type %s\n",

			tagversion, boardid);



		kerneladdr = kerneladdr - BCM963XX_EXTENDED_SIZE;

		rootfsaddr = rootfsaddr - BCM963XX_EXTENDED_SIZE;

		spareaddr = roundup(totallen, master->erasesize) + cfelen;
@@ -169,13 +187,13 @@ static int bcm63xx_parse_cfe_partitions(struct mtd_info *master, 
			rootfsaddr = kerneladdr + kernellen;

			rootfslen = spareaddr - rootfsaddr;

		}

	} else {

		pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",

			buf->header_crc, computed_crc);

	} else if (ret > 0) {

		kernellen = 0;

		rootfslen = 0;

		rootfsaddr = 0;

		spareaddr = cfelen;

	} else {

		goto out;

	}

	sparelen = master->size - spareaddr - nvramlen;