xref: /OK3568_Linux_fs/kernel/drivers/mtd/parsers/ar7part.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright © 2007 Eugene Konev <ejka@openwrt.org>
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * TI AR7 flash partition table.
6*4882a593Smuzhiyun  * Based on ar7 map by Felix Fietkau <nbd@openwrt.org>
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun #include <linux/kernel.h>
10*4882a593Smuzhiyun #include <linux/slab.h>
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include <linux/mtd/mtd.h>
13*4882a593Smuzhiyun #include <linux/mtd/partitions.h>
14*4882a593Smuzhiyun #include <linux/memblock.h>
15*4882a593Smuzhiyun #include <linux/module.h>
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #include <uapi/linux/magic.h>
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun #define AR7_PARTS	4
20*4882a593Smuzhiyun #define ROOT_OFFSET	0xe0000
21*4882a593Smuzhiyun 
22*4882a593Smuzhiyun #define LOADER_MAGIC1	le32_to_cpu(0xfeedfa42)
23*4882a593Smuzhiyun #define LOADER_MAGIC2	le32_to_cpu(0xfeed1281)
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun struct ar7_bin_rec {
26*4882a593Smuzhiyun 	unsigned int checksum;
27*4882a593Smuzhiyun 	unsigned int length;
28*4882a593Smuzhiyun 	unsigned int address;
29*4882a593Smuzhiyun };
30*4882a593Smuzhiyun 
create_mtd_partitions(struct mtd_info * master,const struct mtd_partition ** pparts,struct mtd_part_parser_data * data)31*4882a593Smuzhiyun static int create_mtd_partitions(struct mtd_info *master,
32*4882a593Smuzhiyun 				 const struct mtd_partition **pparts,
33*4882a593Smuzhiyun 				 struct mtd_part_parser_data *data)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun 	struct ar7_bin_rec header;
36*4882a593Smuzhiyun 	unsigned int offset;
37*4882a593Smuzhiyun 	size_t len;
38*4882a593Smuzhiyun 	unsigned int pre_size = master->erasesize, post_size = 0;
39*4882a593Smuzhiyun 	unsigned int root_offset = ROOT_OFFSET;
40*4882a593Smuzhiyun 
41*4882a593Smuzhiyun 	int retries = 10;
42*4882a593Smuzhiyun 	struct mtd_partition *ar7_parts;
43*4882a593Smuzhiyun 
44*4882a593Smuzhiyun 	ar7_parts = kcalloc(AR7_PARTS, sizeof(*ar7_parts), GFP_KERNEL);
45*4882a593Smuzhiyun 	if (!ar7_parts)
46*4882a593Smuzhiyun 		return -ENOMEM;
47*4882a593Smuzhiyun 	ar7_parts[0].name = "loader";
48*4882a593Smuzhiyun 	ar7_parts[0].offset = 0;
49*4882a593Smuzhiyun 	ar7_parts[0].size = master->erasesize;
50*4882a593Smuzhiyun 	ar7_parts[0].mask_flags = MTD_WRITEABLE;
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun 	ar7_parts[1].name = "config";
53*4882a593Smuzhiyun 	ar7_parts[1].offset = 0;
54*4882a593Smuzhiyun 	ar7_parts[1].size = master->erasesize;
55*4882a593Smuzhiyun 	ar7_parts[1].mask_flags = 0;
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun 	do { /* Try 10 blocks starting from master->erasesize */
58*4882a593Smuzhiyun 		offset = pre_size;
59*4882a593Smuzhiyun 		mtd_read(master, offset, sizeof(header), &len,
60*4882a593Smuzhiyun 			 (uint8_t *)&header);
61*4882a593Smuzhiyun 		if (!strncmp((char *)&header, "TIENV0.8", 8))
62*4882a593Smuzhiyun 			ar7_parts[1].offset = pre_size;
63*4882a593Smuzhiyun 		if (header.checksum == LOADER_MAGIC1)
64*4882a593Smuzhiyun 			break;
65*4882a593Smuzhiyun 		if (header.checksum == LOADER_MAGIC2)
66*4882a593Smuzhiyun 			break;
67*4882a593Smuzhiyun 		pre_size += master->erasesize;
68*4882a593Smuzhiyun 	} while (retries--);
69*4882a593Smuzhiyun 
70*4882a593Smuzhiyun 	pre_size = offset;
71*4882a593Smuzhiyun 
72*4882a593Smuzhiyun 	if (!ar7_parts[1].offset) {
73*4882a593Smuzhiyun 		ar7_parts[1].offset = master->size - master->erasesize;
74*4882a593Smuzhiyun 		post_size = master->erasesize;
75*4882a593Smuzhiyun 	}
76*4882a593Smuzhiyun 
77*4882a593Smuzhiyun 	switch (header.checksum) {
78*4882a593Smuzhiyun 	case LOADER_MAGIC1:
79*4882a593Smuzhiyun 		while (header.length) {
80*4882a593Smuzhiyun 			offset += sizeof(header) + header.length;
81*4882a593Smuzhiyun 			mtd_read(master, offset, sizeof(header), &len,
82*4882a593Smuzhiyun 				 (uint8_t *)&header);
83*4882a593Smuzhiyun 		}
84*4882a593Smuzhiyun 		root_offset = offset + sizeof(header) + 4;
85*4882a593Smuzhiyun 		break;
86*4882a593Smuzhiyun 	case LOADER_MAGIC2:
87*4882a593Smuzhiyun 		while (header.length) {
88*4882a593Smuzhiyun 			offset += sizeof(header) + header.length;
89*4882a593Smuzhiyun 			mtd_read(master, offset, sizeof(header), &len,
90*4882a593Smuzhiyun 				 (uint8_t *)&header);
91*4882a593Smuzhiyun 		}
92*4882a593Smuzhiyun 		root_offset = offset + sizeof(header) + 4 + 0xff;
93*4882a593Smuzhiyun 		root_offset &= ~(uint32_t)0xff;
94*4882a593Smuzhiyun 		break;
95*4882a593Smuzhiyun 	default:
96*4882a593Smuzhiyun 		printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
97*4882a593Smuzhiyun 		break;
98*4882a593Smuzhiyun 	}
99*4882a593Smuzhiyun 
100*4882a593Smuzhiyun 	mtd_read(master, root_offset, sizeof(header), &len, (u8 *)&header);
101*4882a593Smuzhiyun 	if (header.checksum != SQUASHFS_MAGIC) {
102*4882a593Smuzhiyun 		root_offset += master->erasesize - 1;
103*4882a593Smuzhiyun 		root_offset &= ~(master->erasesize - 1);
104*4882a593Smuzhiyun 	}
105*4882a593Smuzhiyun 
106*4882a593Smuzhiyun 	ar7_parts[2].name = "linux";
107*4882a593Smuzhiyun 	ar7_parts[2].offset = pre_size;
108*4882a593Smuzhiyun 	ar7_parts[2].size = master->size - pre_size - post_size;
109*4882a593Smuzhiyun 	ar7_parts[2].mask_flags = 0;
110*4882a593Smuzhiyun 
111*4882a593Smuzhiyun 	ar7_parts[3].name = "rootfs";
112*4882a593Smuzhiyun 	ar7_parts[3].offset = root_offset;
113*4882a593Smuzhiyun 	ar7_parts[3].size = master->size - root_offset - post_size;
114*4882a593Smuzhiyun 	ar7_parts[3].mask_flags = 0;
115*4882a593Smuzhiyun 
116*4882a593Smuzhiyun 	*pparts = ar7_parts;
117*4882a593Smuzhiyun 	return AR7_PARTS;
118*4882a593Smuzhiyun }
119*4882a593Smuzhiyun 
120*4882a593Smuzhiyun static struct mtd_part_parser ar7_parser = {
121*4882a593Smuzhiyun 	.parse_fn = create_mtd_partitions,
122*4882a593Smuzhiyun 	.name = "ar7part",
123*4882a593Smuzhiyun };
124*4882a593Smuzhiyun module_mtd_part_parser(ar7_parser);
125*4882a593Smuzhiyun 
126*4882a593Smuzhiyun MODULE_LICENSE("GPL");
127*4882a593Smuzhiyun MODULE_AUTHOR(	"Felix Fietkau <nbd@openwrt.org>, "
128*4882a593Smuzhiyun 		"Eugene Konev <ejka@openwrt.org>");
129*4882a593Smuzhiyun MODULE_DESCRIPTION("MTD partitioning for TI AR7");
130