summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/parsers/parser_trx.c
blob: 4814cf218e178ff8d22a283bfa029988f017c55a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Parser for TRX format partitions
 *
 * Copyright (C) 2012 - 2017 Rafał Miłecki <rafal@milecki.pl>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>

#define TRX_PARSER_MAX_PARTS		4

/* Magics */
#define TRX_MAGIC			0x30524448
#define UBI_EC_MAGIC			0x23494255	/* UBI# */

struct trx_header {
	uint32_t magic;
	uint32_t length;
	uint32_t crc32;
	uint16_t flags;
	uint16_t version;
	uint32_t offset[3];
} __packed;

static const char *parser_trx_data_part_name(struct mtd_info *master,
					     size_t offset)
{
	uint32_t buf;
	size_t bytes_read;
	int err;

	err  = mtd_read(master, offset, sizeof(buf), &bytes_read,
			(uint8_t *)&buf);
	if (err && !mtd_is_bitflip(err)) {
		pr_err("mtd_read error while parsing (offset: 0x%zX): %d\n",
			offset, err);
		goto out_default;
	}

	if (buf == UBI_EC_MAGIC)
		return "ubi";

out_default:
	return "rootfs";
}

static int parser_trx_parse(struct mtd_info *mtd,
			    const struct mtd_partition **pparts,
			    struct mtd_part_parser_data *data)
{
	struct device_node *np = mtd_get_of_node(mtd);
	struct mtd_partition *parts;
	struct mtd_partition *part;
	struct trx_header trx;
	size_t bytes_read;
	uint8_t curr_part = 0, i = 0;
	uint32_t trx_magic = TRX_MAGIC;
	int err;

	/* Get different magic from device tree if specified */
	err = of_property_read_u32(np, "brcm,trx-magic", &trx_magic);
	if (err != 0 && err != -EINVAL)
		pr_err("failed to parse \"brcm,trx-magic\" DT attribute, using default: %d\n", err);

	parts = kcalloc(TRX_PARSER_MAX_PARTS, sizeof(struct mtd_partition),
			GFP_KERNEL);
	if (!parts)
		return -ENOMEM;

	err = mtd_read(mtd, 0, sizeof(trx), &bytes_read, (uint8_t *)&trx);
	if (err) {
		pr_err("MTD reading error: %d\n", err);
		kfree(parts);
		return err;
	}

	if (trx.magic != trx_magic) {
		kfree(parts);
		return -ENOENT;
	}

	/* We have LZMA loader if there is address in offset[2] */
	if (trx.offset[2]) {
		part = &parts[curr_part++];
		part->name = "loader";
		part->offset = trx.offset[i];
		i++;
	}

	if (trx.offset[i]) {
		part = &parts[curr_part++];
		part->name = "linux";
		part->offset = trx.offset[i];
		i++;
	}

	if (trx.offset[i]) {
		part = &parts[curr_part++];
		part->name = parser_trx_data_part_name(mtd, trx.offset[i]);
		part->offset = trx.offset[i];
		i++;
	}

	/*
	 * Assume that every partition ends at the beginning of the one it is
	 * followed by.
	 */
	for (i = 0; i < curr_part; i++) {
		u64 next_part_offset = (i < curr_part - 1) ?
				       parts[i + 1].offset : mtd->size;

		parts[i].size = next_part_offset - parts[i].offset;
	}

	*pparts = parts;
	return i;
};

static const struct of_device_id mtd_parser_trx_of_match_table[] = {
	{ .compatible = "brcm,trx" },
	{},
};
MODULE_DEVICE_TABLE(of, mtd_parser_trx_of_match_table);

static struct mtd_part_parser mtd_parser_trx = {
	.parse_fn = parser_trx_parse,
	.name = "trx",
	.of_match_table = mtd_parser_trx_of_match_table,
};
module_mtd_part_parser(mtd_parser_trx);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Parser for TRX format partitions");