1/*
2 * BCM63XX CFE image tag parser
3 *
4 * Copyright �� 2006-2008  Florian Fainelli <florian@openwrt.org>
5 *			  Mike Albon <malbon@openwrt.org>
6 * Copyright �� 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
7 * Copyright �� 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
22 *
23 */
24
25#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26
27#include <linux/crc32.h>
28#include <linux/module.h>
29#include <linux/kernel.h>
30#include <linux/sizes.h>
31#include <linux/slab.h>
32#include <linux/vmalloc.h>
33#include <linux/mtd/mtd.h>
34#include <linux/mtd/partitions.h>
35
36#include <asm/mach-bcm63xx/bcm63xx_nvram.h>
37#include <asm/mach-bcm63xx/bcm963xx_tag.h>
38#include <asm/mach-bcm63xx/board_bcm963xx.h>
39
40#define BCM63XX_EXTENDED_SIZE	0xBFC00000	/* Extended flash address */
41
42#define BCM63XX_CFE_BLOCK_SIZE	SZ_64K		/* always at least 64KiB */
43
44#define BCM63XX_CFE_MAGIC_OFFSET 0x4e0
45
46static int bcm63xx_detect_cfe(struct mtd_info *master)
47{
48	char buf[9];
49	int ret;
50	size_t retlen;
51
52	ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
53		       (void *)buf);
54	buf[retlen] = 0;
55
56	if (ret)
57		return ret;
58
59	if (strncmp("cfe-v", buf, 5) == 0)
60		return 0;
61
62	/* very old CFE's do not have the cfe-v string, so check for magic */
63	ret = mtd_read(master, BCM63XX_CFE_MAGIC_OFFSET, 8, &retlen,
64		       (void *)buf);
65	buf[retlen] = 0;
66
67	return strncmp("CFE1CFE1", buf, 8);
68}
69
70static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
71					struct mtd_partition **pparts,
72					struct mtd_part_parser_data *data)
73{
74	/* CFE, NVRAM and global Linux are always present */
75	int nrparts = 3, curpart = 0;
76	struct bcm_tag *buf;
77	struct mtd_partition *parts;
78	int ret;
79	size_t retlen;
80	unsigned int rootfsaddr, kerneladdr, spareaddr;
81	unsigned int rootfslen, kernellen, sparelen, totallen;
82	unsigned int cfelen, nvramlen;
83	unsigned int cfe_erasesize;
84	int i;
85	u32 computed_crc;
86	bool rootfs_first = false;
87
88	if (bcm63xx_detect_cfe(master))
89		return -EINVAL;
90
91	cfe_erasesize = max_t(uint32_t, master->erasesize,
92			      BCM63XX_CFE_BLOCK_SIZE);
93
94	cfelen = cfe_erasesize;
95	nvramlen = bcm63xx_nvram_get_psi_size() * SZ_1K;
96	nvramlen = roundup(nvramlen, cfe_erasesize);
97
98	/* Allocate memory for buffer */
99	buf = vmalloc(sizeof(struct bcm_tag));
100	if (!buf)
101		return -ENOMEM;
102
103	/* Get the tag */
104	ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
105		       (void *)buf);
106
107	if (retlen != sizeof(struct bcm_tag)) {
108		vfree(buf);
109		return -EIO;
110	}
111
112	computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
113				offsetof(struct bcm_tag, header_crc));
114	if (computed_crc == buf->header_crc) {
115		char *boardid = &(buf->board_id[0]);
116		char *tagversion = &(buf->tag_version[0]);
117
118		sscanf(buf->flash_image_start, "%u", &rootfsaddr);
119		sscanf(buf->kernel_address, "%u", &kerneladdr);
120		sscanf(buf->kernel_length, "%u", &kernellen);
121		sscanf(buf->total_length, "%u", &totallen);
122
123		pr_info("CFE boot tag found with version %s and board type %s\n",
124			tagversion, boardid);
125
126		kerneladdr = kerneladdr - BCM63XX_EXTENDED_SIZE;
127		rootfsaddr = rootfsaddr - BCM63XX_EXTENDED_SIZE;
128		spareaddr = roundup(totallen, master->erasesize) + cfelen;
129
130		if (rootfsaddr < kerneladdr) {
131			/* default Broadcom layout */
132			rootfslen = kerneladdr - rootfsaddr;
133			rootfs_first = true;
134		} else {
135			/* OpenWrt layout */
136			rootfsaddr = kerneladdr + kernellen;
137			rootfslen = spareaddr - rootfsaddr;
138		}
139	} else {
140		pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",
141			buf->header_crc, computed_crc);
142		kernellen = 0;
143		rootfslen = 0;
144		rootfsaddr = 0;
145		spareaddr = cfelen;
146	}
147	sparelen = master->size - spareaddr - nvramlen;
148
149	/* Determine number of partitions */
150	if (rootfslen > 0)
151		nrparts++;
152
153	if (kernellen > 0)
154		nrparts++;
155
156	/* Ask kernel for more memory */
157	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
158	if (!parts) {
159		vfree(buf);
160		return -ENOMEM;
161	}
162
163	/* Start building partition list */
164	parts[curpart].name = "CFE";
165	parts[curpart].offset = 0;
166	parts[curpart].size = cfelen;
167	curpart++;
168
169	if (kernellen > 0) {
170		int kernelpart = curpart;
171
172		if (rootfslen > 0 && rootfs_first)
173			kernelpart++;
174		parts[kernelpart].name = "kernel";
175		parts[kernelpart].offset = kerneladdr;
176		parts[kernelpart].size = kernellen;
177		curpart++;
178	}
179
180	if (rootfslen > 0) {
181		int rootfspart = curpart;
182
183		if (kernellen > 0 && rootfs_first)
184			rootfspart--;
185		parts[rootfspart].name = "rootfs";
186		parts[rootfspart].offset = rootfsaddr;
187		parts[rootfspart].size = rootfslen;
188		if (sparelen > 0  && !rootfs_first)
189			parts[rootfspart].size += sparelen;
190		curpart++;
191	}
192
193	parts[curpart].name = "nvram";
194	parts[curpart].offset = master->size - nvramlen;
195	parts[curpart].size = nvramlen;
196	curpart++;
197
198	/* Global partition "linux" to make easy firmware upgrade */
199	parts[curpart].name = "linux";
200	parts[curpart].offset = cfelen;
201	parts[curpart].size = master->size - cfelen - nvramlen;
202
203	for (i = 0; i < nrparts; i++)
204		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
205			parts[i].name, parts[i].offset,	parts[i].size);
206
207	pr_info("Spare partition is offset %x and length %x\n",	spareaddr,
208		sparelen);
209
210	*pparts = parts;
211	vfree(buf);
212
213	return nrparts;
214};
215
216static struct mtd_part_parser bcm63xx_cfe_parser = {
217	.owner = THIS_MODULE,
218	.parse_fn = bcm63xx_parse_cfe_partitions,
219	.name = "bcm63xxpart",
220};
221
222static int __init bcm63xx_cfe_parser_init(void)
223{
224	register_mtd_parser(&bcm63xx_cfe_parser);
225	return 0;
226}
227
228static void __exit bcm63xx_cfe_parser_exit(void)
229{
230	deregister_mtd_parser(&bcm63xx_cfe_parser);
231}
232
233module_init(bcm63xx_cfe_parser_init);
234module_exit(bcm63xx_cfe_parser_exit);
235
236MODULE_LICENSE("GPL");
237MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
238MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
239MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
240MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
241MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");
242