mtd/parsers/parser_imagetag.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * BCM63XX CFE image tag parser
0004  *
0005  * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
0006  *            Mike Albon <malbon@openwrt.org>
0007  * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
0008  * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
0009  */
0010
0011 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0012
0013 #include <linux/bcm963xx_tag.h>
0014 #include <linux/crc32.h>
0015 #include <linux/module.h>
0016 #include <linux/kernel.h>
0017 #include <linux/sizes.h>
0018 #include <linux/slab.h>
0019 #include <linux/vmalloc.h>
0020 #include <linux/mtd/mtd.h>
0021 #include <linux/mtd/partitions.h>
0022 #include <linux/of.h>
0023
0024 /* Ensure strings read from flash structs are null terminated */
0025 #define STR_NULL_TERMINATE(x) \
0026     do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
0027
0028 static int bcm963xx_read_imagetag(struct mtd_info *master, const char *name,
0029     loff_t tag_offset, struct bcm_tag *buf)
0030 {
0031     int ret;
0032     size_t retlen;
0033     u32 computed_crc;
0034
0035     ret = mtd_read(master, tag_offset, sizeof(*buf), &retlen, (void *)buf);
0036     if (ret)
0037         return ret;
0038
0039     if (retlen != sizeof(*buf))
0040         return -EIO;
0041
0042     computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
0043                 offsetof(struct bcm_tag, header_crc));
0044     if (computed_crc == buf->header_crc) {
0045         STR_NULL_TERMINATE(buf->board_id);
0046         STR_NULL_TERMINATE(buf->tag_version);
0047
0048         pr_info("%s: CFE image tag found at 0x%llx with version %s, board type %s\n",
0049             name, tag_offset, buf->tag_version, buf->board_id);
0050
0051         return 0;
0052     }
0053
0054     pr_warn("%s: CFE image tag at 0x%llx CRC invalid (expected %08x, actual %08x)\n",
0055         name, tag_offset, buf->header_crc, computed_crc);
0056     return -EINVAL;
0057 }
0058
0059 static int bcm963xx_parse_imagetag_partitions(struct mtd_info *master,
0060                     const struct mtd_partition **pparts,
0061                     struct mtd_part_parser_data *data)
0062 {
0063     /* CFE, NVRAM and global Linux are always present */
0064     int nrparts = 0, curpart = 0;
0065     struct bcm_tag *buf = NULL;
0066     struct mtd_partition *parts;
0067     int ret;
0068     unsigned int rootfsaddr, kerneladdr, spareaddr, offset;
0069     unsigned int rootfslen, kernellen, sparelen, totallen;
0070     int i;
0071     bool rootfs_first = false;
0072
0073     buf = vmalloc(sizeof(struct bcm_tag));
0074     if (!buf)
0075         return -ENOMEM;
0076
0077     /* Get the tag */
0078     ret = bcm963xx_read_imagetag(master, "rootfs", 0, buf);
0079     if (!ret) {
0080         STR_NULL_TERMINATE(buf->flash_image_start);
0081         if (kstrtouint(buf->flash_image_start, 10, &rootfsaddr) ||
0082                 rootfsaddr < BCM963XX_EXTENDED_SIZE) {
0083             pr_err("invalid rootfs address: %*ph\n",
0084                 (int)sizeof(buf->flash_image_start),
0085                 buf->flash_image_start);
0086             ret = -EINVAL;
0087             goto out;
0088         }
0089
0090         STR_NULL_TERMINATE(buf->kernel_address);
0091         if (kstrtouint(buf->kernel_address, 10, &kerneladdr) ||
0092                 kerneladdr < BCM963XX_EXTENDED_SIZE) {
0093             pr_err("invalid kernel address: %*ph\n",
0094                 (int)sizeof(buf->kernel_address),
0095                 buf->kernel_address);
0096             ret = -EINVAL;
0097             goto out;
0098         }
0099
0100         STR_NULL_TERMINATE(buf->kernel_length);
0101         if (kstrtouint(buf->kernel_length, 10, &kernellen)) {
0102             pr_err("invalid kernel length: %*ph\n",
0103                 (int)sizeof(buf->kernel_length),
0104                 buf->kernel_length);
0105             ret = -EINVAL;
0106             goto out;
0107         }
0108
0109         STR_NULL_TERMINATE(buf->total_length);
0110         if (kstrtouint(buf->total_length, 10, &totallen)) {
0111             pr_err("invalid total length: %*ph\n",
0112                 (int)sizeof(buf->total_length),
0113                 buf->total_length);
0114             ret = -EINVAL;
0115             goto out;
0116         }
0117
0118         /*
0119          * Addresses are flash absolute, so convert to partition
0120          * relative addresses. Assume either kernel or rootfs will
0121          * directly follow the image tag.
0122          */
0123         if (rootfsaddr < kerneladdr)
0124             offset = rootfsaddr - sizeof(struct bcm_tag);
0125         else
0126             offset = kerneladdr - sizeof(struct bcm_tag);
0127
0128         kerneladdr = kerneladdr - offset;
0129         rootfsaddr = rootfsaddr - offset;
0130         spareaddr = roundup(totallen, master->erasesize);
0131
0132         if (rootfsaddr < kerneladdr) {
0133             /* default Broadcom layout */
0134             rootfslen = kerneladdr - rootfsaddr;
0135             rootfs_first = true;
0136         } else {
0137             /* OpenWrt layout */
0138             rootfsaddr = kerneladdr + kernellen;
0139             rootfslen = spareaddr - rootfsaddr;
0140         }
0141     } else {
0142         goto out;
0143     }
0144     sparelen = master->size - spareaddr;
0145
0146     /* Determine number of partitions */
0147     if (rootfslen > 0)
0148         nrparts++;
0149
0150     if (kernellen > 0)
0151         nrparts++;
0152
0153     parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
0154     if (!parts) {
0155         ret = -ENOMEM;
0156         goto out;
0157     }
0158
0159     /* Start building partition list */
0160     if (kernellen > 0) {
0161         int kernelpart = curpart;
0162
0163         if (rootfslen > 0 && rootfs_first)
0164             kernelpart++;
0165         parts[kernelpart].name = "kernel";
0166         parts[kernelpart].offset = kerneladdr;
0167         parts[kernelpart].size = kernellen;
0168         curpart++;
0169     }
0170
0171     if (rootfslen > 0) {
0172         int rootfspart = curpart;
0173
0174         if (kernellen > 0 && rootfs_first)
0175             rootfspart--;
0176         parts[rootfspart].name = "rootfs";
0177         parts[rootfspart].offset = rootfsaddr;
0178         parts[rootfspart].size = rootfslen;
0179         if (sparelen > 0  && !rootfs_first)
0180             parts[rootfspart].size += sparelen;
0181         curpart++;
0182     }
0183
0184     for (i = 0; i < nrparts; i++)
0185         pr_info("Partition %d is %s offset %llx and length %llx\n", i,
0186             parts[i].name, parts[i].offset, parts[i].size);
0187
0188     pr_info("Spare partition is offset %x and length %x\n", spareaddr,
0189         sparelen);
0190
0191     *pparts = parts;
0192     ret = 0;
0193
0194 out:
0195     vfree(buf);
0196
0197     if (ret)
0198         return ret;
0199
0200     return nrparts;
0201 }
0202
0203 static const struct of_device_id parse_bcm963xx_imagetag_match_table[] = {
0204     { .compatible = "brcm,bcm963xx-imagetag" },
0205     {},
0206 };
0207 MODULE_DEVICE_TABLE(of, parse_bcm963xx_imagetag_match_table);
0208
0209 static struct mtd_part_parser bcm963xx_imagetag_parser = {
0210     .parse_fn = bcm963xx_parse_imagetag_partitions,
0211     .name = "bcm963xx-imagetag",
0212     .of_match_table = parse_bcm963xx_imagetag_match_table,
0213 };
0214 module_mtd_part_parser(bcm963xx_imagetag_parser);
0215
0216 MODULE_LICENSE("GPL");
0217 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
0218 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
0219 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
0220 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com>");
0221 MODULE_DESCRIPTION("MTD parser for BCM963XX CFE Image Tag partitions");