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/bcm963xx_nvram.h>
 28#include <linux/bcm963xx_tag.h>
 29#include <linux/crc32.h>
 30#include <linux/module.h>
 31#include <linux/kernel.h>
 32#include <linux/sizes.h>
 33#include <linux/slab.h>
 34#include <linux/vmalloc.h>
 35#include <linux/mtd/mtd.h>
 36#include <linux/mtd/partitions.h>
 37
 38#define BCM963XX_CFE_BLOCK_SIZE		SZ_64K	/* always at least 64KiB */
 39
 40#define BCM963XX_CFE_MAGIC_OFFSET	0x4e0
 41#define BCM963XX_CFE_VERSION_OFFSET	0x570
 42#define BCM963XX_NVRAM_OFFSET		0x580
 43
 44/* Ensure strings read from flash structs are null terminated */
 45#define STR_NULL_TERMINATE(x) \
 46	do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
 47
 48static int bcm63xx_detect_cfe(struct mtd_info *master)
 49{
 50	char buf[9];
 51	int ret;
 52	size_t retlen;
 53
 54	ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
 55		       (void *)buf);
 56	buf[retlen] = 0;
 57
 58	if (ret)
 59		return ret;
 60
 61	if (strncmp("cfe-v", buf, 5) == 0)
 62		return 0;
 63
 64	/* very old CFE's do not have the cfe-v string, so check for magic */
 65	ret = mtd_read(master, BCM963XX_CFE_MAGIC_OFFSET, 8, &retlen,
 66		       (void *)buf);
 67	buf[retlen] = 0;
 68
 69	return strncmp("CFE1CFE1", buf, 8);
 70}
 71
 72static int bcm63xx_read_nvram(struct mtd_info *master,
 73	struct bcm963xx_nvram *nvram)
 74{
 75	u32 actual_crc, expected_crc;
 76	size_t retlen;
 77	int ret;
 78
 79	/* extract nvram data */
 80	ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
 81			&retlen, (void *)nvram);
 82	if (ret)
 83		return ret;
 84
 85	ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
 86	if (ret)
 87		pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
 88			expected_crc, actual_crc);
 89
 90	if (!nvram->psi_size)
 91		nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;
 92
 93	return 0;
 94}
 95
 96static int bcm63xx_read_image_tag(struct mtd_info *master, const char *name,
 97	loff_t tag_offset, struct bcm_tag *buf)
 98{
 99	int ret;
100	size_t retlen;
101	u32 computed_crc;
102
103	ret = mtd_read(master, tag_offset, sizeof(*buf), &retlen, (void *)buf);
104	if (ret)
105		return ret;
106
107	if (retlen != sizeof(*buf))
108		return -EIO;
109
110	computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
111				offsetof(struct bcm_tag, header_crc));
112	if (computed_crc == buf->header_crc) {
113		STR_NULL_TERMINATE(buf->board_id);
114		STR_NULL_TERMINATE(buf->tag_version);
115
116		pr_info("%s: CFE image tag found at 0x%llx with version %s, board type %s\n",
117			name, tag_offset, buf->tag_version, buf->board_id);
118
119		return 0;
120	}
121
122	pr_warn("%s: CFE image tag at 0x%llx CRC invalid (expected %08x, actual %08x)\n",
123		name, tag_offset, buf->header_crc, computed_crc);
124	return 1;
125}
126
127static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
128	const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
129{
130	/* CFE, NVRAM and global Linux are always present */
131	int nrparts = 3, curpart = 0;
132	struct bcm_tag *buf = NULL;
133	struct mtd_partition *parts;
134	int ret;
135	unsigned int rootfsaddr, kerneladdr, spareaddr;
136	unsigned int rootfslen, kernellen, sparelen, totallen;
137	unsigned int cfelen, nvramlen;
138	unsigned int cfe_erasesize;
139	int i;
140	bool rootfs_first = false;
141
142	cfe_erasesize = max_t(uint32_t, master->erasesize,
143			      BCM963XX_CFE_BLOCK_SIZE);
144
145	cfelen = cfe_erasesize;
146	nvramlen = nvram->psi_size * SZ_1K;
147	nvramlen = roundup(nvramlen, cfe_erasesize);
148
149	buf = vmalloc(sizeof(struct bcm_tag));
150	if (!buf)
151		return -ENOMEM;
152
153	/* Get the tag */
154	ret = bcm63xx_read_image_tag(master, "rootfs", cfelen, buf);
155	if (!ret) {
156		STR_NULL_TERMINATE(buf->flash_image_start);
157		if (kstrtouint(buf->flash_image_start, 10, &rootfsaddr) ||
158				rootfsaddr < BCM963XX_EXTENDED_SIZE) {
159			pr_err("invalid rootfs address: %*ph\n",
160				(int)sizeof(buf->flash_image_start),
161				buf->flash_image_start);
162			goto invalid_tag;
163		}
164
165		STR_NULL_TERMINATE(buf->kernel_address);
166		if (kstrtouint(buf->kernel_address, 10, &kerneladdr) ||
167				kerneladdr < BCM963XX_EXTENDED_SIZE) {
168			pr_err("invalid kernel address: %*ph\n",
169				(int)sizeof(buf->kernel_address),
170				buf->kernel_address);
171			goto invalid_tag;
172		}
173
174		STR_NULL_TERMINATE(buf->kernel_length);
175		if (kstrtouint(buf->kernel_length, 10, &kernellen)) {
176			pr_err("invalid kernel length: %*ph\n",
177				(int)sizeof(buf->kernel_length),
178				buf->kernel_length);
179			goto invalid_tag;
180		}
181
182		STR_NULL_TERMINATE(buf->total_length);
183		if (kstrtouint(buf->total_length, 10, &totallen)) {
184			pr_err("invalid total length: %*ph\n",
185				(int)sizeof(buf->total_length),
186				buf->total_length);
187			goto invalid_tag;
188		}
189
190		kerneladdr = kerneladdr - BCM963XX_EXTENDED_SIZE;
191		rootfsaddr = rootfsaddr - BCM963XX_EXTENDED_SIZE;
192		spareaddr = roundup(totallen, master->erasesize) + cfelen;
193
194		if (rootfsaddr < kerneladdr) {
195			/* default Broadcom layout */
196			rootfslen = kerneladdr - rootfsaddr;
197			rootfs_first = true;
198		} else {
199			/* OpenWrt layout */
200			rootfsaddr = kerneladdr + kernellen;
201			rootfslen = spareaddr - rootfsaddr;
202		}
203	} else if (ret > 0) {
204invalid_tag:
205		kernellen = 0;
206		rootfslen = 0;
207		rootfsaddr = 0;
208		spareaddr = cfelen;
209	} else {
210		goto out;
211	}
212	sparelen = master->size - spareaddr - nvramlen;
213
214	/* Determine number of partitions */
215	if (rootfslen > 0)
216		nrparts++;
217
218	if (kernellen > 0)
219		nrparts++;
220
221	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
222	if (!parts) {
223		ret = -ENOMEM;
224		goto out;
225	}
226
227	/* Start building partition list */
228	parts[curpart].name = "CFE";
229	parts[curpart].offset = 0;
230	parts[curpart].size = cfelen;
231	curpart++;
232
233	if (kernellen > 0) {
234		int kernelpart = curpart;
235
236		if (rootfslen > 0 && rootfs_first)
237			kernelpart++;
238		parts[kernelpart].name = "kernel";
239		parts[kernelpart].offset = kerneladdr;
240		parts[kernelpart].size = kernellen;
241		curpart++;
242	}
243
244	if (rootfslen > 0) {
245		int rootfspart = curpart;
246
247		if (kernellen > 0 && rootfs_first)
248			rootfspart--;
249		parts[rootfspart].name = "rootfs";
250		parts[rootfspart].offset = rootfsaddr;
251		parts[rootfspart].size = rootfslen;
252		if (sparelen > 0  && !rootfs_first)
253			parts[rootfspart].size += sparelen;
254		curpart++;
255	}
256
257	parts[curpart].name = "nvram";
258	parts[curpart].offset = master->size - nvramlen;
259	parts[curpart].size = nvramlen;
260	curpart++;
261
262	/* Global partition "linux" to make easy firmware upgrade */
263	parts[curpart].name = "linux";
264	parts[curpart].offset = cfelen;
265	parts[curpart].size = master->size - cfelen - nvramlen;
266
267	for (i = 0; i < nrparts; i++)
268		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
269			parts[i].name, parts[i].offset,	parts[i].size);
270
271	pr_info("Spare partition is offset %x and length %x\n",	spareaddr,
272		sparelen);
273
274	*pparts = parts;
275	ret = 0;
276
277out:
278	vfree(buf);
279
280	if (ret)
281		return ret;
282
283	return nrparts;
284}
285
286static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
287					const struct mtd_partition **pparts,
288					struct mtd_part_parser_data *data)
289{
290	struct bcm963xx_nvram *nvram = NULL;
291	int ret;
292
293	if (bcm63xx_detect_cfe(master))
294		return -EINVAL;
295
296	nvram = vzalloc(sizeof(*nvram));
297	if (!nvram)
298		return -ENOMEM;
299
300	ret = bcm63xx_read_nvram(master, nvram);
301	if (ret)
302		goto out;
303
304	if (!mtd_type_is_nand(master))
305		ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
306	else
307		ret = -EINVAL;
308
309out:
310	vfree(nvram);
311	return ret;
312};
313
314static struct mtd_part_parser bcm63xx_cfe_parser = {
315	.parse_fn = bcm63xx_parse_cfe_partitions,
316	.name = "bcm63xxpart",
317};
318module_mtd_part_parser(bcm63xx_cfe_parser);
319
320MODULE_LICENSE("GPL");
321MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
322MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
323MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
324MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
325MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");