[PATCH PROOF 2/1] mtd: add TRX parser splitting firmware partition
Rafał Miłecki
zajec5 at gmail.com
Mon May 18 05:34:54 PDT 2015
This is just a proof of concept, not clean enough for being applied.
It results in creating subpartitions in a following way:
[ 1.890000] Creating 3 MTD partitions on "bcm47xxsflash":
[ 1.900000] 0x000000000000-0x000000020000 : "boot"
[ 1.900000] 0x000000020000-0x0000007f0000 : "firmware"
[ 1.940000] 3 trx_parser partitions found on MTD device firmware
[ 1.980000] 0x00000002001c-0x00000002090c : "loader"
[ 2.000000] 0x00000002090c-0x00000013b800 : "linux"
[ 2.030000] 0x00000013b800-0x0000007f0000 : "rootfs"
[ 2.060000] 0x0000007f0000-0x000000800000 : "nvram"
Signed-off-by: Rafał Miłecki <zajec5 at gmail.com>
---
drivers/mtd/Makefile | 1 +
drivers/mtd/mtdsplit_trx.c | 124 +++++++++++++++++++++++++++++++++++++++++
include/linux/mtd/partitions.h | 1 +
3 files changed, 126 insertions(+)
create mode 100644 drivers/mtd/mtdsplit_trx.c
diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 99bb9a1..c43742f 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_MTD_AFS_PARTS) += afs.o
obj-$(CONFIG_MTD_AR7_PARTS) += ar7part.o
obj-$(CONFIG_MTD_BCM63XX_PARTS) += bcm63xxpart.o
obj-$(CONFIG_MTD_BCM47XX_PARTS) += bcm47xxpart.o
+obj-y += mtdsplit_trx.o
# 'Users' - code which presents functionality to userspace.
obj-$(CONFIG_MTD_BLKDEVS) += mtd_blkdevs.o
diff --git a/drivers/mtd/mtdsplit_trx.c b/drivers/mtd/mtdsplit_trx.c
new file mode 100644
index 0000000..d075cc0e
--- /dev/null
+++ b/drivers/mtd/mtdsplit_trx.c
@@ -0,0 +1,124 @@
+/*
+ * TRX subpartitioning
+ *
+ * Copyright (C) 2015 Rafał Miłecki <zajec5 at gmail.com>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#define TRX_PARSER_MAX_PARTS 4
+#define TRX_MAGIC 0x30524448
+
+struct trx_header {
+ uint32_t magic;
+ uint32_t length;
+ uint32_t crc32;
+ uint16_t flags;
+ uint16_t version;
+ uint32_t offset[3];
+} __packed;
+
+static void trx_parser_add_part(struct mtd_partition *part, char *name,
+ u64 offset, uint32_t mask_flags)
+{
+ part->name = name;
+ part->offset = offset;
+ part->mask_flags = mask_flags;
+}
+
+static int trx_parser_parse(struct mtd_info *master,
+ struct mtd_partition **pparts,
+ struct mtd_part_parser_data *data)
+{
+ struct mtd_partition *parts;
+ struct trx_header trx;
+ size_t bytes_read;
+ int curr_part = 0;
+ int ret, i;
+
+ /* Alloc */
+ parts = kzalloc(sizeof(struct mtd_partition) * TRX_PARSER_MAX_PARTS,
+ GFP_KERNEL);
+ if (!parts)
+ return -ENOMEM;
+
+ /* Read beginning of the block */
+ ret = mtd_read(master, 0, sizeof(trx), &bytes_read, (uint8_t *)&trx);
+ if (ret < 0 || bytes_read != sizeof(trx)) {
+ kfree(parts);
+ return -EIO;
+ }
+
+ /* TRX */
+ if (le32_to_cpu(trx.magic) != TRX_MAGIC) {
+ kfree(parts);
+ return -EIO;
+ }
+
+ i = 0;
+ /* We have LZMA loader if offset[2] points to sth */
+ if (trx.offset[2]) {
+ trx_parser_add_part(&parts[curr_part++], "loader",
+ trx.offset[i], 0);
+ i++;
+ }
+
+ if (trx.offset[i]) {
+ trx_parser_add_part(&parts[curr_part++], "linux",
+ trx.offset[i], 0);
+ i++;
+ }
+
+ if (trx.offset[i]) {
+ trx_parser_add_part(&parts[curr_part++], "rootfs",
+ trx.offset[i], 0);
+ i++;
+ }
+
+ /*
+ * Assume that partitions end at the beginning of the one they are
+ * followed by.
+ */
+ for (i = 0; i < curr_part; i++) {
+ u64 next_part_offset = (i < curr_part - 1) ?
+ parts[i + 1].offset : master->size;
+
+ parts[i].size = next_part_offset - parts[i].offset;
+ }
+
+ *pparts = parts;
+ return curr_part;
+};
+
+static struct mtd_part_parser trx_parser = {
+ .owner = THIS_MODULE,
+ .parse_fn = trx_parser_parse,
+ .name = "trx_parser",
+ .type = MTD_PARTITION_TYPE_FIRMWARE,
+};
+
+static int __init trx_parser_init(void)
+{
+ register_mtd_parser(&trx_parser);
+ return 0;
+}
+
+static void __exit trx_parser_exit(void)
+{
+ deregister_mtd_parser(&trx_parser);
+}
+
+module_init(trx_parser_init);
+module_exit(trx_parser_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TRX subpartitioning");
diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
index 4d2432a..295e417 100644
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -13,6 +13,7 @@
enum mtd_partition_type {
MTD_PARTITION_TYPE_GENERIC = 0,
+ MTD_PARTITION_TYPE_FIRMWARE,
};
/*
--
1.8.4.5
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