1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * BCM63XX CFE image tag parser
4  *
5  * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
6  *			  Mike Albon <malbon@openwrt.org>
7  * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
8  * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/bcm963xx_nvram.h>
14 #include <linux/bcm963xx_tag.h>
15 #include <linux/crc32.h>
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/sizes.h>
19 #include <linux/slab.h>
20 #include <linux/vmalloc.h>
21 #include <linux/mtd/mtd.h>
22 #include <linux/mtd/partitions.h>
23 #include <linux/of.h>
24 
25 #define BCM963XX_CFE_BLOCK_SIZE		SZ_64K	/* always at least 64KiB */
26 
27 #define BCM963XX_CFE_MAGIC_OFFSET	0x4e0
28 #define BCM963XX_CFE_VERSION_OFFSET	0x570
29 #define BCM963XX_NVRAM_OFFSET		0x580
30 
31 /* Ensure strings read from flash structs are null terminated */
32 #define STR_NULL_TERMINATE(x) \
33 	do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
34 
35 static int bcm63xx_detect_cfe(struct mtd_info *master)
36 {
37 	char buf[9];
38 	int ret;
39 	size_t retlen;
40 
41 	ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
42 		       (void *)buf);
43 	buf[retlen] = 0;
44 
45 	if (ret)
46 		return ret;
47 
48 	if (strncmp("cfe-v", buf, 5) == 0)
49 		return 0;
50 
51 	/* very old CFE's do not have the cfe-v string, so check for magic */
52 	ret = mtd_read(master, BCM963XX_CFE_MAGIC_OFFSET, 8, &retlen,
53 		       (void *)buf);
54 	buf[retlen] = 0;
55 
56 	return strncmp("CFE1CFE1", buf, 8);
57 }
58 
59 static int bcm63xx_read_nvram(struct mtd_info *master,
60 	struct bcm963xx_nvram *nvram)
61 {
62 	u32 actual_crc, expected_crc;
63 	size_t retlen;
64 	int ret;
65 
66 	/* extract nvram data */
67 	ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
68 			&retlen, (void *)nvram);
69 	if (ret)
70 		return ret;
71 
72 	ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
73 	if (ret)
74 		pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
75 			expected_crc, actual_crc);
76 
77 	if (!nvram->psi_size)
78 		nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
79 
80 	return 0;
81 }
82 
83 static const char * const bcm63xx_cfe_part_types[] = {
84 	"bcm963xx-imagetag",
85 	NULL,
86 };
87 
88 static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
89 	const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
90 {
91 	struct mtd_partition *parts;
92 	int nrparts = 3, curpart = 0;
93 	unsigned int cfelen, nvramlen;
94 	unsigned int cfe_erasesize;
95 	int i;
96 
97 	cfe_erasesize = max_t(uint32_t, master->erasesize,
98 			      BCM963XX_CFE_BLOCK_SIZE);
99 
100 	cfelen = cfe_erasesize;
101 	nvramlen = nvram->psi_size * SZ_1K;
102 	nvramlen = roundup(nvramlen, cfe_erasesize);
103 
104 	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
105 	if (!parts)
106 		return -ENOMEM;
107 
108 	/* Start building partition list */
109 	parts[curpart].name = "CFE";
110 	parts[curpart].offset = 0;
111 	parts[curpart].size = cfelen;
112 	curpart++;
113 
114 	parts[curpart].name = "nvram";
115 	parts[curpart].offset = master->size - nvramlen;
116 	parts[curpart].size = nvramlen;
117 	curpart++;
118 
119 	/* Global partition "linux" to make easy firmware upgrade */
120 	parts[curpart].name = "linux";
121 	parts[curpart].offset = cfelen;
122 	parts[curpart].size = master->size - cfelen - nvramlen;
123 	parts[curpart].types = bcm63xx_cfe_part_types;
124 
125 	for (i = 0; i < nrparts; i++)
126 		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
127 			parts[i].name, parts[i].offset,	parts[i].size);
128 
129 	*pparts = parts;
130 
131 	return nrparts;
132 }
133 
134 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
135 					const struct mtd_partition **pparts,
136 					struct mtd_part_parser_data *data)
137 {
138 	struct bcm963xx_nvram *nvram = NULL;
139 	int ret;
140 
141 	if (bcm63xx_detect_cfe(master))
142 		return -EINVAL;
143 
144 	nvram = vzalloc(sizeof(*nvram));
145 	if (!nvram)
146 		return -ENOMEM;
147 
148 	ret = bcm63xx_read_nvram(master, nvram);
149 	if (ret)
150 		goto out;
151 
152 	if (!mtd_type_is_nand(master))
153 		ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
154 	else
155 		ret = -EINVAL;
156 
157 out:
158 	vfree(nvram);
159 	return ret;
160 };
161 
162 static const struct of_device_id parse_bcm63xx_cfe_match_table[] = {
163 	{ .compatible = "brcm,bcm963xx-cfe-nor-partitions" },
164 	{},
165 };
166 MODULE_DEVICE_TABLE(of, parse_bcm63xx_cfe_match_table);
167 
168 static struct mtd_part_parser bcm63xx_cfe_parser = {
169 	.parse_fn = bcm63xx_parse_cfe_partitions,
170 	.name = "bcm63xxpart",
171 	.of_match_table = parse_bcm63xx_cfe_match_table,
172 };
173 module_mtd_part_parser(bcm63xx_cfe_parser);
174 
175 MODULE_LICENSE("GPL");
176 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
177 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
178 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
179 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
180 MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
181