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 #ifdef CONFIG_MIPS
26 #include <asm/bootinfo.h>
27 #include <asm/fw/cfe/cfe_api.h>
28 #endif /* CONFIG_MIPS */
29 
30 #define BCM963XX_CFE_BLOCK_SIZE		SZ_64K	/* always at least 64KiB */
31 
32 #define BCM963XX_CFE_MAGIC_OFFSET	0x4e0
33 #define BCM963XX_CFE_VERSION_OFFSET	0x570
34 #define BCM963XX_NVRAM_OFFSET		0x580
35 
36 /* Ensure strings read from flash structs are null terminated */
37 #define STR_NULL_TERMINATE(x) \
38 	do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
39 
40 static inline int bcm63xx_detect_cfe(void)
41 {
42 	int ret = 0;
43 
44 #ifdef CONFIG_MIPS
45 	ret = (fw_arg3 == CFE_EPTSEAL);
46 #endif /* CONFIG_MIPS */
47 
48 	return ret;
49 }
50 
51 static int bcm63xx_read_nvram(struct mtd_info *master,
52 	struct bcm963xx_nvram *nvram)
53 {
54 	u32 actual_crc, expected_crc;
55 	size_t retlen;
56 	int ret;
57 
58 	/* extract nvram data */
59 	ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
60 			&retlen, (void *)nvram);
61 	if (ret)
62 		return ret;
63 
64 	ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
65 	if (ret)
66 		pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
67 			expected_crc, actual_crc);
68 
69 	if (!nvram->psi_size)
70 		nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
71 
72 	return 0;
73 }
74 
75 static const char * const bcm63xx_cfe_part_types[] = {
76 	"bcm963xx-imagetag",
77 	NULL,
78 };
79 
80 static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
81 	const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
82 {
83 	struct mtd_partition *parts;
84 	int nrparts = 3, curpart = 0;
85 	unsigned int cfelen, nvramlen;
86 	unsigned int cfe_erasesize;
87 	int i;
88 
89 	cfe_erasesize = max_t(uint32_t, master->erasesize,
90 			      BCM963XX_CFE_BLOCK_SIZE);
91 
92 	cfelen = cfe_erasesize;
93 	nvramlen = nvram->psi_size * SZ_1K;
94 	nvramlen = roundup(nvramlen, cfe_erasesize);
95 
96 	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
97 	if (!parts)
98 		return -ENOMEM;
99 
100 	/* Start building partition list */
101 	parts[curpart].name = "CFE";
102 	parts[curpart].offset = 0;
103 	parts[curpart].size = cfelen;
104 	curpart++;
105 
106 	parts[curpart].name = "nvram";
107 	parts[curpart].offset = master->size - nvramlen;
108 	parts[curpart].size = nvramlen;
109 	curpart++;
110 
111 	/* Global partition "linux" to make easy firmware upgrade */
112 	parts[curpart].name = "linux";
113 	parts[curpart].offset = cfelen;
114 	parts[curpart].size = master->size - cfelen - nvramlen;
115 	parts[curpart].types = bcm63xx_cfe_part_types;
116 
117 	for (i = 0; i < nrparts; i++)
118 		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
119 			parts[i].name, parts[i].offset,	parts[i].size);
120 
121 	*pparts = parts;
122 
123 	return nrparts;
124 }
125 
126 static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
127 					const struct mtd_partition **pparts,
128 					struct mtd_part_parser_data *data)
129 {
130 	struct bcm963xx_nvram *nvram = NULL;
131 	int ret;
132 
133 	if (!bcm63xx_detect_cfe())
134 		return -EINVAL;
135 
136 	nvram = vzalloc(sizeof(*nvram));
137 	if (!nvram)
138 		return -ENOMEM;
139 
140 	ret = bcm63xx_read_nvram(master, nvram);
141 	if (ret)
142 		goto out;
143 
144 	if (!mtd_type_is_nand(master))
145 		ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
146 	else
147 		ret = -EINVAL;
148 
149 out:
150 	vfree(nvram);
151 	return ret;
152 };
153 
154 static const struct of_device_id parse_bcm63xx_cfe_match_table[] = {
155 	{ .compatible = "brcm,bcm963xx-cfe-nor-partitions" },
156 	{},
157 };
158 MODULE_DEVICE_TABLE(of, parse_bcm63xx_cfe_match_table);
159 
160 static struct mtd_part_parser bcm63xx_cfe_parser = {
161 	.parse_fn = bcm63xx_parse_cfe_partitions,
162 	.name = "bcm63xxpart",
163 	.of_match_table = parse_bcm63xx_cfe_match_table,
164 };
165 module_mtd_part_parser(bcm63xx_cfe_parser);
166 
167 MODULE_LICENSE("GPL");
168 MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
169 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
170 MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
171 MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
172 MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
173