kernel: add support for mtdsplit-fit offset

Support devices that has vendor custom header before FIT image.

Some devices has vendor custom header before FIT image. In this case mtd-
split can not find FIT image and it results in rootfs mount failure.
Please refer iptime,a6004mx device for further examples.

Signed-off-by: Yoonji Park <koreapyj@dcmys.kr>

diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_fit.c b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_fit.c
index d8fb74ea381239a0d05fc6c8789ccd1bc47ff9a0..3b71597d23d52b3d99cf584c96ae6b7143d13564 100644 (file)
--- a/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_fit.c
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_fit.c
@@ -199,6 +199,7 @@ mtdsplit_fit_parse(struct mtd_info *mtd,
        struct fdt_header hdr;
        size_t hdr_len, retlen;
        size_t offset;
+       u32 offset_start = 0;
        size_t fit_offset, fit_size;
        size_t rootfs_offset, rootfs_size;
        size_t data_size, img_total, max_size = 0;
@@ -211,11 +212,13 @@ mtdsplit_fit_parse(struct mtd_info *mtd,
        if (cmdline_match && !strstr(saved_command_line, cmdline_match))
                return -ENODEV;
 
+       of_property_read_u32(np, "openwrt,fit-offset", &offset_start);
+
        hdr_len = sizeof(struct fdt_header);
 
        /* Parse the MTD device & search for the FIT image location */
        for(offset = 0; offset + hdr_len <= mtd->size; offset += mtd->erasesize) {
-               ret = mtd_read(mtd, offset, hdr_len, &retlen, (void*) &hdr);
+               ret = mtd_read(mtd, offset + offset_start, hdr_len, &retlen, (void*) &hdr);
                if (ret) {
                        pr_err("read error in \"%s\" at offset 0x%llx\n",
                               mtd->name, (unsigned long long) offset);
@@ -259,7 +262,7 @@ mtdsplit_fit_parse(struct mtd_info *mtd,
                enum mtdsplit_part_type type;
 
                /* Search for the rootfs partition after the FIT image */
-               ret = mtd_find_rootfs_from(mtd, fit_offset + fit_size, mtd->size,
+               ret = mtd_find_rootfs_from(mtd, fit_offset + fit_size + offset_start, mtd->size,
                                           &rootfs_offset, &type);
                if (ret) {
                        pr_info("no rootfs found after FIT image in \"%s\"\n",
@@ -275,7 +278,7 @@ mtdsplit_fit_parse(struct mtd_info *mtd,
 
                parts[0].name = KERNEL_PART_NAME;
                parts[0].offset = fit_offset;
-               parts[0].size = mtd_rounddown_to_eb(fit_size, mtd) + mtd->erasesize;
+               parts[0].size = mtd_rounddown_to_eb(fit_size + offset_start, mtd) + mtd->erasesize;
 
                if (type == MTDSPLIT_PART_TYPE_UBI)
                        parts[1].name = UBI_PART_NAME;
@@ -290,7 +293,7 @@ mtdsplit_fit_parse(struct mtd_info *mtd,
        } else {
                /* Search for rootfs_data after FIT external data */
                fit = kzalloc(fit_size, GFP_KERNEL);
-               ret = mtd_read(mtd, offset, fit_size, &retlen, fit);
+               ret = mtd_read(mtd, offset, fit_size + offset_start, &retlen, fit);
                if (ret) {
                        pr_err("read error in \"%s\" at offset 0x%llx\n",
                               mtd->name, (unsigned long long) offset);