kernel: add mtd split support for trx images

[openwrt/openwrt.git] / target / linux / generic / files / drivers / mtd / mtdsplit / mtdsplit_trx.c

diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_trx.c b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_trx.c
new file mode 100644 (file)
index 0000000..6efffce
--- /dev/null
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_trx.c
@@ -0,0 +1,147 @@
+/*
+ *  Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ */
+
+#define pr_fmt(fmt)    KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/byteorder/generic.h>
+
+#include "mtdsplit.h"
+
+#define TRX_MAGIC   0x30524448  /* "HDR0" */
+
+struct trx_header {
+       __le32 magic;
+       __le32 len;
+       __le32 crc32;
+       __le32 flag_version;
+       __le32 offset[4];
+};
+
+static int
+read_trx_header(struct mtd_info *mtd, size_t offset,
+                  struct trx_header *header)
+{
+       size_t header_len;
+       size_t retlen;
+       int ret;
+
+       header_len = sizeof(*header);
+       ret = mtd_read(mtd, offset, header_len, &retlen,
+                      (unsigned char *) header);
+       if (ret) {
+               pr_debug("read error in \"%s\"\n", mtd->name);
+               return ret;
+       }
+
+       if (retlen != header_len) {
+               pr_debug("short read in \"%s\"\n", mtd->name);
+               return -EIO;
+       }
+
+       return 0;
+}
+
+static int
+mtdsplit_parse_trx(struct mtd_info *master,
+                  struct mtd_partition **pparts,
+                  struct mtd_part_parser_data *data)
+{
+       struct mtd_partition *parts;
+       struct trx_header hdr;
+       int nr_parts;
+       size_t offset;
+       size_t trx_offset;
+       size_t trx_size = 0;
+       size_t rootfs_offset;
+       size_t rootfs_size = 0;
+       int ret;
+
+       nr_parts = 2;
+       parts = kzalloc(nr_parts * sizeof(*parts), GFP_KERNEL);
+       if (!parts)
+               return -ENOMEM;
+
+       /* find trx image on erase block boundaries */
+       for (offset = 0; offset < master->size; offset += master->erasesize) {
+               trx_size = 0;
+
+               ret = read_trx_header(master, offset, &hdr);
+               if (ret)
+                       continue;
+
+               if (hdr.magic != cpu_to_le32(TRX_MAGIC)) {
+                       pr_debug("no valid trx header found in \"%s\" at offset %llx\n",
+                                master->name, (unsigned long long) offset);
+                       continue;
+               }
+
+               trx_size = le32_to_cpu(hdr.len);
+               if ((offset + trx_size) > master->size) {
+                       pr_debug("trx image exceeds MTD device \"%s\"\n",
+                                master->name);
+                       continue;
+               }
+               break;
+       }
+
+       if (trx_size == 0) {
+               pr_debug("no trx header found in \"%s\"\n", master->name);
+               ret = -ENODEV;
+               goto err;
+       }
+
+       trx_offset = offset + hdr.offset[0];
+       rootfs_offset = offset + hdr.offset[1];
+       rootfs_size = master->size - rootfs_offset;
+       trx_size = rootfs_offset - trx_offset;
+
+       if (rootfs_size == 0) {
+               pr_debug("no rootfs found in \"%s\"\n", master->name);
+               ret = -ENODEV;
+               goto err;
+       }
+
+       parts[0].name = KERNEL_PART_NAME;
+       parts[0].offset = trx_offset;
+       parts[0].size = trx_size;
+
+       parts[1].name = ROOTFS_PART_NAME;
+       parts[1].offset = rootfs_offset;
+       parts[1].size = rootfs_size;
+
+       *pparts = parts;
+       return nr_parts;
+
+err:
+       kfree(parts);
+       return ret;
+}
+
+static struct mtd_part_parser trx_parser = {
+       .owner = THIS_MODULE,
+       .name = "trx-fw",
+       .parse_fn = mtdsplit_parse_trx,
+       .type = MTD_PARSER_TYPE_FIRMWARE,
+};
+
+static int __init mtdsplit_trx_init(void)
+{
+       register_mtd_parser(&trx_parser);
+
+       return 0;
+}
+
+module_init(mtdsplit_trx_init);