From 7fffa694a8917af0c553ab48290a57e3674aa5d3 Mon Sep 17 00:00:00 2001 From: Simon Arlott Date: Sun, 13 Dec 2015 22:51:02 +0000 Subject: [PATCH] mtd: bcm63xxpart: Extract read of image tag to separate function Extract image tag reading and CRC check to a separate function. Signed-off-by: Simon Arlott Signed-off-by: Brian Norris --- drivers/mtd/bcm63xxpart.c | 62 ++++++++++++++++++++++++++++++----------------- 1 file changed, 40 insertions(+), 22 deletions(-) diff --git a/drivers/mtd/bcm63xxpart.c b/drivers/mtd/bcm63xxpart.c index 1eea8b6..eafbf52 100644 --- a/drivers/mtd/bcm63xxpart.c +++ b/drivers/mtd/bcm63xxpart.c @@ -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; -- 2.7.4