[mirror_ubuntu-artful-kernel.git] / drivers / mtd / redboot.c

/*
 * Parse RedBoot-style Flash Image System (FIS) tables and
 * produce a Linux partition array to match.
 *
 * Copyright © 2001      Red Hat UK Limited
 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/vmalloc.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/module.h>

struct fis_image_desc {
    unsigned char name[16];      // Null terminated name
    uint32_t	  flash_base;    // Address within FLASH of image
    uint32_t	  mem_base;      // Address in memory where it executes
    uint32_t	  size;          // Length of image
    uint32_t	  entry_point;   // Execution entry point
    uint32_t	  data_length;   // Length of actual data
    unsigned char _pad[256-(16+7*sizeof(uint32_t))];
    uint32_t	  desc_cksum;    // Checksum over image descriptor
    uint32_t	  file_cksum;    // Checksum over image data
};

struct fis_list {
	struct fis_image_desc *img;
	struct fis_list *next;
};

static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
module_param(directory, int, 0);

static inline int redboot_checksum(struct fis_image_desc *img)
{
	/* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
	return 1;
}

static int parse_redboot_partitions(struct mtd_info *master,
				    struct mtd_partition **pparts,
				    struct mtd_part_parser_data *data)
{
	int nrparts = 0;
	struct fis_image_desc *buf;
	struct mtd_partition *parts;
	struct fis_list *fl = NULL, *tmp_fl;
	int ret, i;
	size_t retlen;
	char *names;
	char *nullname;
	int namelen = 0;
	int nulllen = 0;
	int numslots;
	unsigned long offset;
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	static char nullstring[] = "unallocated";
#endif

	if ( directory < 0 ) {
		offset = master->size + directory * master->erasesize;
		while (mtd_can_have_bb(master) &&
		       mtd_block_isbad(master, offset)) {
			if (!offset) {
			nogood:
				printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n");
				return -EIO;
			}
			offset -= master->erasesize;
		}
	} else {
		offset = directory * master->erasesize;
		while (mtd_can_have_bb(master) &&
		       mtd_block_isbad(master, offset)) {
			offset += master->erasesize;
			if (offset == master->size)
				goto nogood;
		}
	}
	buf = vmalloc(master->erasesize);

	if (!buf)
		return -ENOMEM;

	printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
	       master->name, offset);

	ret = mtd_read(master, offset, master->erasesize, &retlen,
		       (void *)buf);

	if (ret)
		goto out;

	if (retlen != master->erasesize) {
		ret = -EIO;
		goto out;
	}

	numslots = (master->erasesize / sizeof(struct fis_image_desc));
	for (i = 0; i < numslots; i++) {
		if (!memcmp(buf[i].name, "FIS directory", 14)) {
			/* This is apparently the FIS directory entry for the
			 * FIS directory itself.  The FIS directory size is
			 * one erase block; if the buf[i].size field is
			 * swab32(erasesize) then we know we are looking at
			 * a byte swapped FIS directory - swap all the entries!
			 * (NOTE: this is 'size' not 'data_length'; size is
			 * the full size of the entry.)
			 */

			/* RedBoot can combine the FIS directory and
			   config partitions into a single eraseblock;
			   we assume wrong-endian if either the swapped
			   'size' matches the eraseblock size precisely,
			   or if the swapped size actually fits in an
			   eraseblock while the unswapped size doesn't. */
			if (swab32(buf[i].size) == master->erasesize ||
			    (buf[i].size > master->erasesize
			     && swab32(buf[i].size) < master->erasesize)) {
				int j;
				/* Update numslots based on actual FIS directory size */
				numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc);
				for (j = 0; j < numslots; ++j) {

					/* A single 0xff denotes a deleted entry.
					 * Two of them in a row is the end of the table.
					 */
					if (buf[j].name[0] == 0xff) {
				  		if (buf[j].name[1] == 0xff) {
							break;
						} else {
							continue;
						}
					}

					/* The unsigned long fields were written with the
					 * wrong byte sex, name and pad have no byte sex.
					 */
					swab32s(&buf[j].flash_base);
					swab32s(&buf[j].mem_base);
					swab32s(&buf[j].size);
					swab32s(&buf[j].entry_point);
					swab32s(&buf[j].data_length);
					swab32s(&buf[j].desc_cksum);
					swab32s(&buf[j].file_cksum);
				}
			} else if (buf[i].size < master->erasesize) {
				/* Update numslots based on actual FIS directory size */
				numslots = buf[i].size / sizeof(struct fis_image_desc);
			}
			break;
		}
	}
	if (i == numslots) {
		/* Didn't find it */
		printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
		       master->name);
		ret = 0;
		goto out;
	}

	for (i = 0; i < numslots; i++) {
		struct fis_list *new_fl, **prev;

		if (buf[i].name[0] == 0xff) {
			if (buf[i].name[1] == 0xff) {
				break;
			} else {
				continue;
			}
		}
		if (!redboot_checksum(&buf[i]))
			break;

		new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
		namelen += strlen(buf[i].name)+1;
		if (!new_fl) {
			ret = -ENOMEM;
			goto out;
		}
		new_fl->img = &buf[i];
		if (data && data->origin)
			buf[i].flash_base -= data->origin;
		else
			buf[i].flash_base &= master->size-1;

		/* I'm sure the JFFS2 code has done me permanent damage.
		 * I now think the following is _normal_
		 */
		prev = &fl;
		while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
			prev = &(*prev)->next;
		new_fl->next = *prev;
		*prev = new_fl;

		nrparts++;
	}
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	if (fl->img->flash_base) {
		nrparts++;
		nulllen = sizeof(nullstring);
	}

	for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
		if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
			nrparts++;
			nulllen = sizeof(nullstring);
		}
	}
#endif
	parts = kzalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);

	if (!parts) {
		ret = -ENOMEM;
		goto out;
	}

	nullname = (char *)&parts[nrparts];
#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	if (nulllen > 0) {
		strcpy(nullname, nullstring);
	}
#endif
	names = nullname + nulllen;

	i=0;

#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	if (fl->img->flash_base) {
	       parts[0].name = nullname;
	       parts[0].size = fl->img->flash_base;
	       parts[0].offset = 0;
		i++;
	}
#endif
	for ( ; i<nrparts; i++) {
		parts[i].size = fl->img->size;
		parts[i].offset = fl->img->flash_base;
		parts[i].name = names;

		strcpy(names, fl->img->name);
#ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
		if (!memcmp(names, "RedBoot", 8) ||
				!memcmp(names, "RedBoot config", 15) ||
				!memcmp(names, "FIS directory", 14)) {
			parts[i].mask_flags = MTD_WRITEABLE;
		}
#endif
		names += strlen(names)+1;

#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
		if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
			i++;
			parts[i].offset = parts[i-1].size + parts[i-1].offset;
			parts[i].size = fl->next->img->flash_base - parts[i].offset;
			parts[i].name = nullname;
		}
#endif
		tmp_fl = fl;
		fl = fl->next;
		kfree(tmp_fl);
	}
	ret = nrparts;
	*pparts = parts;
 out:
	while (fl) {
		struct fis_list *old = fl;
		fl = fl->next;
		kfree(old);
	}
	vfree(buf);
	return ret;
}

static struct mtd_part_parser redboot_parser = {
	.owner = THIS_MODULE,
	.parse_fn = parse_redboot_partitions,
	.name = "RedBoot",
};

/* mtd parsers will request the module by parser name */
MODULE_ALIAS("RedBoot");

static int __init redboot_parser_init(void)
{
	return register_mtd_parser(&redboot_parser);
}

static void __exit redboot_parser_exit(void)
{
	deregister_mtd_parser(&redboot_parser);
}

module_init(redboot_parser_init);
module_exit(redboot_parser_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* Parse RedBoot-style Flash Image System (FIS) tables and
1da177e4 LT	3	* produce a Linux partition array to match.
a1452a37 DW	4	*
	5	* Copyright © 2001 Red Hat UK Limited
	6	* Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	21	*
1da177e4 LT	22	*/
	23
	24	#include <linux/kernel.h>
	25	#include <linux/slab.h>
	26	#include <linux/init.h>
	27	#include <linux/vmalloc.h>
	28
	29	#include <linux/mtd/mtd.h>
	30	#include <linux/mtd/partitions.h>
a0e5cc58	31	#include <linux/module.h>
1da177e4 LT	32
	33	struct fis_image_desc {
	34	unsigned char name[16]; // Null terminated name
b020bb7d BD	35	uint32_t flash_base; // Address within FLASH of image
	36	uint32_t mem_base; // Address in memory where it executes
	37	uint32_t size; // Length of image
	38	uint32_t entry_point; // Execution entry point
	39	uint32_t data_length; // Length of actual data
	40	unsigned char _pad[256-(16+7*sizeof(uint32_t))];
	41	uint32_t desc_cksum; // Checksum over image descriptor
	42	uint32_t file_cksum; // Checksum over image data
1da177e4 LT	43	};
	44
	45	struct fis_list {
	46	struct fis_image_desc *img;
	47	struct fis_list *next;
	48	};
	49
	50	static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
	51	module_param(directory, int, 0);
	52
	53	static inline int redboot_checksum(struct fis_image_desc *img)
	54	{
	55	/* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
	56	return 1;
	57	}
	58
97894cda	59	static int parse_redboot_partitions(struct mtd_info *master,
c7975330 DES	60	struct mtd_partition **pparts,
c7975330 DES	61	struct mtd_part_parser_data *data)
1da177e4 LT	62	{
	63	int nrparts = 0;
	64	struct fis_image_desc *buf;
	65	struct mtd_partition *parts;
	66	struct fis_list fl = NULL, tmp_fl;
	67	int ret, i;
	68	size_t retlen;
	69	char *names;
	70	char *nullname;
	71	int namelen = 0;
	72	int nulllen = 0;
	73	int numslots;
	74	unsigned long offset;
	75	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	76	static char nullstring[] = "unallocated";
	77	#endif
	78
3c441baa DW	79	if ( directory < 0 ) {
3c441baa DW	80	offset = master->size + directory * master->erasesize;
8f461a73	81	while (mtd_can_have_bb(master) &&
7086c19d	82	mtd_block_isbad(master, offset)) {
3c441baa DW	83	if (!offset) {
	84	nogood:
	85	printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n");
	86	return -EIO;
	87	}
	88	offset -= master->erasesize;
	89	}
	90	} else {
	91	offset = directory * master->erasesize;
8f461a73	92	while (mtd_can_have_bb(master) &&
7086c19d	93	mtd_block_isbad(master, offset)) {
3c441baa DW	94	offset += master->erasesize;
	95	if (offset == master->size)
	96	goto nogood;
	97	}
	98	}
1da177e4 LT	99	buf = vmalloc(master->erasesize);
	100
	101	if (!buf)
	102	return -ENOMEM;
	103
1da177e4 LT	104	printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
	105	master->name, offset);
	106
329ad399 AB	107	ret = mtd_read(master, offset, master->erasesize, &retlen,
329ad399 AB	108	(void *)buf);
1da177e4 LT	109
	110	if (ret)
	111	goto out;
	112
	113	if (retlen != master->erasesize) {
	114	ret = -EIO;
	115	goto out;
	116	}
	117
	118	numslots = (master->erasesize / sizeof(struct fis_image_desc));
	119	for (i = 0; i < numslots; i++) {
9cff3372 JB	120	if (!memcmp(buf[i].name, "FIS directory", 14)) {
	121	/* This is apparently the FIS directory entry for the
	122	* FIS directory itself. The FIS directory size is
77a33135	123	* one erase block; if the buf[i].size field is
9cff3372 JB	124	* swab32(erasesize) then we know we are looking at
9cff3372 JB	125	* a byte swapped FIS directory - swap all the entries!
77a33135	126	* (NOTE: this is 'size' not 'data_length'; size is
9cff3372 JB	127	* the full size of the entry.)
9cff3372 JB	128	*/
7ca353a4 DW	129
	130	/* RedBoot can combine the FIS directory and
	131	config partitions into a single eraseblock;
	132	we assume wrong-endian if either the swapped
	133	'size' matches the eraseblock size precisely,
	134	or if the swapped size actually fits in an
	135	eraseblock while the unswapped size doesn't. */
	136	if (swab32(buf[i].size) == master->erasesize \|\|
	137	(buf[i].size > master->erasesize
	138	&& swab32(buf[i].size) < master->erasesize)) {
9cff3372	139	int j;
11192146 RW	140	/* Update numslots based on actual FIS directory size */
11192146 RW	141	numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc);
f33665d9 RW	142	for (j = 0; j < numslots; ++j) {
	143
	144	/* A single 0xff denotes a deleted entry.
	145	* Two of them in a row is the end of the table.
	146	*/
	147	if (buf[j].name[0] == 0xff) {
	148	if (buf[j].name[1] == 0xff) {
	149	break;
	150	} else {
	151	continue;
	152	}
	153	}
	154
9cff3372 JB	155	/* The unsigned long fields were written with the
	156	* wrong byte sex, name and pad have no byte sex.
	157	*/
77a33135 JB	158	swab32s(&buf[j].flash_base);
	159	swab32s(&buf[j].mem_base);
	160	swab32s(&buf[j].size);
	161	swab32s(&buf[j].entry_point);
	162	swab32s(&buf[j].data_length);
	163	swab32s(&buf[j].desc_cksum);
	164	swab32s(&buf[j].file_cksum);
9cff3372	165	}
7ca353a4	166	} else if (buf[i].size < master->erasesize) {
11192146 RW	167	/* Update numslots based on actual FIS directory size */
11192146 RW	168	numslots = buf[i].size / sizeof(struct fis_image_desc);
9cff3372	169	}
1da177e4	170	break;
9cff3372	171	}
1da177e4 LT	172	}
	173	if (i == numslots) {
	174	/* Didn't find it */
	175	printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
	176	master->name);
	177	ret = 0;
	178	goto out;
	179	}
	180
	181	for (i = 0; i < numslots; i++) {
	182	struct fis_list new_fl, *prev;
	183
f33665d9 RW	184	if (buf[i].name[0] == 0xff) {
	185	if (buf[i].name[1] == 0xff) {
	186	break;
	187	} else {
	188	continue;
	189	}
	190	}
1da177e4 LT	191	if (!redboot_checksum(&buf[i]))
	192	break;
	193
	194	new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
	195	namelen += strlen(buf[i].name)+1;
	196	if (!new_fl) {
	197	ret = -ENOMEM;
	198	goto out;
	199	}
	200	new_fl->img = &buf[i];
c7975330 DES	201	if (data && data->origin)
	202	buf[i].flash_base -= data->origin;
	203	else
	204	buf[i].flash_base &= master->size-1;
1da177e4 LT	205
	206	/* I'm sure the JFFS2 code has done me permanent damage.
	207	* I now think the following is _normal_
	208	*/
	209	prev = &fl;
	210	while(prev && (prev)->img->flash_base < new_fl->img->flash_base)
	211	prev = &(*prev)->next;
	212	new_fl->next = *prev;
	213	*prev = new_fl;
	214
	215	nrparts++;
	216	}
	217	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	218	if (fl->img->flash_base) {
	219	nrparts++;
	220	nulllen = sizeof(nullstring);
	221	}
	222
	223	for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
	224	if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
	225	nrparts++;
	226	nulllen = sizeof(nullstring);
	227	}
	228	}
	229	#endif
95b93a0c	230	parts = kzalloc(sizeof(parts)nrparts + nulllen + namelen, GFP_KERNEL);
1da177e4 LT	231
	232	if (!parts) {
	233	ret = -ENOMEM;
	234	goto out;
	235	}
	236
1da177e4 LT	237	nullname = (char *)&parts[nrparts];
	238	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	239	if (nulllen > 0) {
	240	strcpy(nullname, nullstring);
	241	}
	242	#endif
	243	names = nullname + nulllen;
	244
	245	i=0;
	246
	247	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	248	if (fl->img->flash_base) {
	249	parts[0].name = nullname;
	250	parts[0].size = fl->img->flash_base;
	251	parts[0].offset = 0;
	252	i++;
	253	}
	254	#endif
	255	for ( ; i<nrparts; i++) {
	256	parts[i].size = fl->img->size;
	257	parts[i].offset = fl->img->flash_base;
	258	parts[i].name = names;
	259
	260	strcpy(names, fl->img->name);
	261	#ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
	262	if (!memcmp(names, "RedBoot", 8) \|\|
	263	!memcmp(names, "RedBoot config", 15) \|\|
	264	!memcmp(names, "FIS directory", 14)) {
	265	parts[i].mask_flags = MTD_WRITEABLE;
	266	}
	267	#endif
	268	names += strlen(names)+1;
	269
	270	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	271	if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
	272	i++;
	273	parts[i].offset = parts[i-1].size + parts[i-1].offset;
	274	parts[i].size = fl->next->img->flash_base - parts[i].offset;
	275	parts[i].name = nullname;
	276	}
	277	#endif
	278	tmp_fl = fl;
	279	fl = fl->next;
	280	kfree(tmp_fl);
	281	}
	282	ret = nrparts;
	283	*pparts = parts;
	284	out:
	285	while (fl) {
	286	struct fis_list *old = fl;
	287	fl = fl->next;
	288	kfree(old);
	289	}
	290	vfree(buf);
	291	return ret;
	292	}
	293
	294	static struct mtd_part_parser redboot_parser = {
	295	.owner = THIS_MODULE,
	296	.parse_fn = parse_redboot_partitions,
	297	.name = "RedBoot",
	298	};
	299
d5de1907 AS	300	/* mtd parsers will request the module by parser name */
	301	MODULE_ALIAS("RedBoot");
	302
1da177e4 LT	303	static int __init redboot_parser_init(void)
	304	{
	305	return register_mtd_parser(&redboot_parser);
	306	}
	307
	308	static void __exit redboot_parser_exit(void)
	309	{
	310	deregister_mtd_parser(&redboot_parser);
	311	}
	312
	313	module_init(redboot_parser_init);
	314	module_exit(redboot_parser_exit);
	315
	316	MODULE_LICENSE("GPL");
44d1b980	317	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1da177e4	318	MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");