[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,
                             unsigned long fis_origin)
{
	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 (master->block_isbad && 
		       master->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 (master->block_isbad && 
		       master->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 = master->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 (fis_origin) {
                        buf[i].flash_base -= fis_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",
};

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,
1da177e4 LT	60	struct mtd_partition **pparts,
	61	unsigned long fis_origin)
	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 ) {
	80	offset = master->size + directory * master->erasesize;
	81	while (master->block_isbad &&
	82	master->block_isbad(master, offset)) {
	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;
	92	while (master->block_isbad &&
	93	master->block_isbad(master, offset)) {
	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
	107	ret = master->read(master, offset,
	108	master->erasesize, &retlen, (void *)buf);
	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];
	201	if (fis_origin) {
	202	buf[i].flash_base -= fis_origin;
	203	} else {
	204	buf[i].flash_base &= master->size-1;
	205	}
	206
	207	/* I'm sure the JFFS2 code has done me permanent damage.
	208	* I now think the following is _normal_
	209	*/
	210	prev = &fl;
	211	while(prev && (prev)->img->flash_base < new_fl->img->flash_base)
	212	prev = &(*prev)->next;
	213	new_fl->next = *prev;
	214	*prev = new_fl;
	215
	216	nrparts++;
	217	}
	218	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	219	if (fl->img->flash_base) {
	220	nrparts++;
	221	nulllen = sizeof(nullstring);
	222	}
	223
	224	for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
	225	if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
	226	nrparts++;
	227	nulllen = sizeof(nullstring);
	228	}
	229	}
	230	#endif
95b93a0c	231	parts = kzalloc(sizeof(parts)nrparts + nulllen + namelen, GFP_KERNEL);
1da177e4 LT	232
	233	if (!parts) {
	234	ret = -ENOMEM;
	235	goto out;
	236	}
	237
1da177e4 LT	238	nullname = (char *)&parts[nrparts];
	239	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	240	if (nulllen > 0) {
	241	strcpy(nullname, nullstring);
	242	}
	243	#endif
	244	names = nullname + nulllen;
	245
	246	i=0;
	247
	248	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	249	if (fl->img->flash_base) {
	250	parts[0].name = nullname;
	251	parts[0].size = fl->img->flash_base;
	252	parts[0].offset = 0;
	253	i++;
	254	}
	255	#endif
	256	for ( ; i<nrparts; i++) {
	257	parts[i].size = fl->img->size;
	258	parts[i].offset = fl->img->flash_base;
	259	parts[i].name = names;
	260
	261	strcpy(names, fl->img->name);
	262	#ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
	263	if (!memcmp(names, "RedBoot", 8) \|\|
	264	!memcmp(names, "RedBoot config", 15) \|\|
	265	!memcmp(names, "FIS directory", 14)) {
	266	parts[i].mask_flags = MTD_WRITEABLE;
	267	}
	268	#endif
	269	names += strlen(names)+1;
	270
	271	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	272	if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
	273	i++;
	274	parts[i].offset = parts[i-1].size + parts[i-1].offset;
	275	parts[i].size = fl->next->img->flash_base - parts[i].offset;
	276	parts[i].name = nullname;
	277	}
	278	#endif
	279	tmp_fl = fl;
	280	fl = fl->next;
	281	kfree(tmp_fl);
	282	}
	283	ret = nrparts;
	284	*pparts = parts;
	285	out:
	286	while (fl) {
	287	struct fis_list *old = fl;
	288	fl = fl->next;
	289	kfree(old);
	290	}
	291	vfree(buf);
	292	return ret;
	293	}
	294
	295	static struct mtd_part_parser redboot_parser = {
	296	.owner = THIS_MODULE,
	297	.parse_fn = parse_redboot_partitions,
	298	.name = "RedBoot",
	299	};
	300
	301	static int __init redboot_parser_init(void)
302	{
303	return register_mtd_parser(&redboot_parser);
304	}
305
306	static void __exit redboot_parser_exit(void)
307	{
308	deregister_mtd_parser(&redboot_parser);
309	}
310
311	module_init(redboot_parser_init);
312	module_exit(redboot_parser_exit);
313
314	MODULE_LICENSE("GPL");
44d1b980	315	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1da177e4	316	MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");