Skip to content

Commit 3cf7f13

Browse files
rmileckiDavid Woodhouse
rmilecki
authored and
David Woodhouse
committed
mtd: bcm47part driver for BCM47XX chipsets
This driver provides parser detecting partitions on BCM47XX flash memories. It has many differences in comparison to BCM63XX, like: 1) Different CFE with no more trivial MAGICs 2) More partitions types (board_data, ML, POT) 3) Supporting more than 1 flash on a device which resulted in decision of writing new parser. It uses generic mtd interface and was successfully tested with Netgear WNDR4500 router which has 2 flash memories: serial one and NAND one. Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
1 parent aa3c5dc commit 3cf7f13

File tree

3 files changed

+210
-0
lines changed

3 files changed

+210
-0
lines changed

‎drivers/mtd/Kconfig

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -148,6 +148,13 @@ config MTD_BCM63XX_PARTS
148148
This provides partions parsing for BCM63xx devices with CFE
149149
bootloaders.
150150

151+
config MTD_BCM47XX_PARTS
152+
tristate "BCM47XX partitioning support"
153+
depends on BCM47XX
154+
help
155+
This provides partitions parser for devices based on BCM47xx
156+
boards.
157+
151158
comment "User Modules And Translation Layers"
152159

153160
config MTD_CHAR

‎drivers/mtd/Makefile

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -12,6 +12,7 @@ obj-$(CONFIG_MTD_CMDLINE_PARTS) += cmdlinepart.o
1212
obj-$(CONFIG_MTD_AFS_PARTS) += afs.o
1313
obj-$(CONFIG_MTD_AR7_PARTS) += ar7part.o
1414
obj-$(CONFIG_MTD_BCM63XX_PARTS) += bcm63xxpart.o
15+
obj-$(CONFIG_MTD_BCM47XX_PARTS) += bcm47xxpart.o
1516

1617
# 'Users' - code which presents functionality to userspace.
1718
obj-$(CONFIG_MTD_CHAR) += mtdchar.o

‎drivers/mtd/bcm47xxpart.c

Lines changed: 202 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,202 @@
1+
/*
2+
* BCM47XX MTD partitioning
3+
*
4+
* Copyright © 2012 Rafał Miłecki <zajec5@gmail.com>
5+
*
6+
* This program is free software; you can redistribute it and/or modify
7+
* it under the terms of the GNU General Public License version 2 as
8+
* published by the Free Software Foundation.
9+
*
10+
*/
11+
12+
#include <linux/module.h>
13+
#include <linux/kernel.h>
14+
#include <linux/slab.h>
15+
#include <linux/mtd/mtd.h>
16+
#include <linux/mtd/partitions.h>
17+
#include <asm/mach-bcm47xx/nvram.h>
18+
19+
/* 10 parts were found on sflash on Netgear WNDR4500 */
20+
#define BCM47XXPART_MAX_PARTS 12
21+
22+
/*
23+
* Amount of bytes we read when analyzing each block of flash memory.
24+
* Set it big enough to allow detecting partition and reading important data.
25+
*/
26+
#define BCM47XXPART_BYTES_TO_READ 0x404
27+
28+
/* Magics */
29+
#define BOARD_DATA_MAGIC 0x5246504D /* MPFR */
30+
#define POT_MAGIC1 0x54544f50 /* POTT */
31+
#define POT_MAGIC2 0x504f /* OP */
32+
#define ML_MAGIC1 0x39685a42
33+
#define ML_MAGIC2 0x26594131
34+
#define TRX_MAGIC 0x30524448
35+
36+
struct trx_header {
37+
uint32_t magic;
38+
uint32_t length;
39+
uint32_t crc32;
40+
uint16_t flags;
41+
uint16_t version;
42+
uint32_t offset[3];
43+
} __packed;
44+
45+
static void bcm47xxpart_add_part(struct mtd_partition *part, char *name,
46+
u64 offset, uint32_t mask_flags)
47+
{
48+
part->name = name;
49+
part->offset = offset;
50+
part->mask_flags = mask_flags;
51+
}
52+
53+
static int bcm47xxpart_parse(struct mtd_info *master,
54+
struct mtd_partition **pparts,
55+
struct mtd_part_parser_data *data)
56+
{
57+
struct mtd_partition *parts;
58+
uint8_t i, curr_part = 0;
59+
uint32_t *buf;
60+
size_t bytes_read;
61+
uint32_t offset;
62+
uint32_t blocksize = 0x10000;
63+
struct trx_header *trx;
64+
65+
/* Alloc */
66+
parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
67+
GFP_KERNEL);
68+
buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);
69+
70+
/* Parse block by block looking for magics */
71+
for (offset = 0; offset <= master->size - blocksize;
72+
offset += blocksize) {
73+
/* Nothing more in higher memory */
74+
if (offset >= 0x2000000)
75+
break;
76+
77+
if (curr_part > BCM47XXPART_MAX_PARTS) {
78+
pr_warn("Reached maximum number of partitions, scanning stopped!\n");
79+
break;
80+
}
81+
82+
/* Read beginning of the block */
83+
if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
84+
&bytes_read, (uint8_t *)buf) < 0) {
85+
pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
86+
offset);
87+
continue;
88+
}
89+
90+
/* CFE has small NVRAM at 0x400 */
91+
if (buf[0x400 / 4] == NVRAM_HEADER) {
92+
bcm47xxpart_add_part(&parts[curr_part++], "boot",
93+
offset, MTD_WRITEABLE);
94+
continue;
95+
}
96+
97+
/* Standard NVRAM */
98+
if (buf[0x000 / 4] == NVRAM_HEADER) {
99+
bcm47xxpart_add_part(&parts[curr_part++], "nvram",
100+
offset, 0);
101+
continue;
102+
}
103+
104+
/*
105+
* board_data starts with board_id which differs across boards,
106+
* but we can use 'MPFR' (hopefully) magic at 0x100
107+
*/
108+
if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {
109+
bcm47xxpart_add_part(&parts[curr_part++], "board_data",
110+
offset, MTD_WRITEABLE);
111+
continue;
112+
}
113+
114+
/* POT(TOP) */
115+
if (buf[0x000 / 4] == POT_MAGIC1 &&
116+
(buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {
117+
bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,
118+
MTD_WRITEABLE);
119+
continue;
120+
}
121+
122+
/* ML */
123+
if (buf[0x010 / 4] == ML_MAGIC1 &&
124+
buf[0x014 / 4] == ML_MAGIC2) {
125+
bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,
126+
MTD_WRITEABLE);
127+
continue;
128+
}
129+
130+
/* TRX */
131+
if (buf[0x000 / 4] == TRX_MAGIC) {
132+
trx = (struct trx_header *)buf;
133+
134+
i = 0;
135+
/* We have LZMA loader if offset[2] points to sth */
136+
if (trx->offset[2]) {
137+
bcm47xxpart_add_part(&parts[curr_part++],
138+
"loader",
139+
offset + trx->offset[i],
140+
0);
141+
i++;
142+
}
143+
144+
bcm47xxpart_add_part(&parts[curr_part++], "linux",
145+
offset + trx->offset[i], 0);
146+
i++;
147+
148+
/*
149+
* Pure rootfs size is known and can be calculated as:
150+
* trx->length - trx->offset[i]. We don't fill it as
151+
* we want to have jffs2 (overlay) in the same mtd.
152+
*/
153+
bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
154+
offset + trx->offset[i], 0);
155+
i++;
156+
157+
/*
158+
* We have whole TRX scanned, skip to the next part. Use
159+
* roundown (not roundup), as the loop will increase
160+
* offset in next step.
161+
*/
162+
offset = rounddown(offset + trx->length, blocksize);
163+
continue;
164+
}
165+
}
166+
kfree(buf);
167+
168+
/*
169+
* Assume that partitions end at the beginning of the one they are
170+
* followed by.
171+
*/
172+
for (i = 0; i < curr_part - 1; i++)
173+
parts[i].size = parts[i + 1].offset - parts[i].offset;
174+
if (curr_part > 0)
175+
parts[curr_part - 1].size =
176+
master->size - parts[curr_part - 1].offset;
177+
178+
*pparts = parts;
179+
return curr_part;
180+
};
181+
182+
static struct mtd_part_parser bcm47xxpart_mtd_parser = {
183+
.owner = THIS_MODULE,
184+
.parse_fn = bcm47xxpart_parse,
185+
.name = "bcm47xxpart",
186+
};
187+
188+
static int __init bcm47xxpart_init(void)
189+
{
190+
return register_mtd_parser(&bcm47xxpart_mtd_parser);
191+
}
192+
193+
static void __exit bcm47xxpart_exit(void)
194+
{
195+
deregister_mtd_parser(&bcm47xxpart_mtd_parser);
196+
}
197+
198+
module_init(bcm47xxpart_init);
199+
module_exit(bcm47xxpart_exit);
200+
201+
MODULE_LICENSE("GPL");
202+
MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");

0 commit comments

Comments
 (0)