[linux.git] / drivers / mtd / redboot.c

/*
 * Parse RedBoot-style Flash Image System (FIS) tables and
 * produce a Linux partition array to match.
 */

#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>

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 <[email protected]>");
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
	3	* produce a Linux partition array to match.
	4	*/
	5
	6	#include <linux/kernel.h>
	7	#include <linux/slab.h>
	8	#include <linux/init.h>
	9	#include <linux/vmalloc.h>
	10
	11	#include <linux/mtd/mtd.h>
	12	#include <linux/mtd/partitions.h>
	13
	14	struct fis_image_desc {
	15	unsigned char name[16]; // Null terminated name
b020bb7d BD	16	uint32_t flash_base; // Address within FLASH of image
	17	uint32_t mem_base; // Address in memory where it executes
	18	uint32_t size; // Length of image
	19	uint32_t entry_point; // Execution entry point
	20	uint32_t data_length; // Length of actual data
	21	unsigned char _pad[256-(16+7*sizeof(uint32_t))];
	22	uint32_t desc_cksum; // Checksum over image descriptor
	23	uint32_t file_cksum; // Checksum over image data
1da177e4 LT	24	};
	25
	26	struct fis_list {
	27	struct fis_image_desc *img;
	28	struct fis_list *next;
	29	};
	30
	31	static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
	32	module_param(directory, int, 0);
	33
	34	static inline int redboot_checksum(struct fis_image_desc *img)
	35	{
	36	/* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
	37	return 1;
	38	}
	39
97894cda	40	static int parse_redboot_partitions(struct mtd_info *master,
1da177e4 LT	41	struct mtd_partition **pparts,
	42	unsigned long fis_origin)
	43	{
	44	int nrparts = 0;
	45	struct fis_image_desc *buf;
	46	struct mtd_partition *parts;
	47	struct fis_list fl = NULL, tmp_fl;
	48	int ret, i;
	49	size_t retlen;
	50	char *names;
	51	char *nullname;
	52	int namelen = 0;
	53	int nulllen = 0;
	54	int numslots;
	55	unsigned long offset;
	56	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	57	static char nullstring[] = "unallocated";
	58	#endif
	59
3c441baa DW	60	if ( directory < 0 ) {
	61	offset = master->size + directory * master->erasesize;
	62	while (master->block_isbad &&
	63	master->block_isbad(master, offset)) {
	64	if (!offset) {
	65	nogood:
	66	printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n");
	67	return -EIO;
	68	}
	69	offset -= master->erasesize;
	70	}
	71	} else {
	72	offset = directory * master->erasesize;
	73	while (master->block_isbad &&
	74	master->block_isbad(master, offset)) {
	75	offset += master->erasesize;
	76	if (offset == master->size)
	77	goto nogood;
	78	}
	79	}
1da177e4 LT	80	buf = vmalloc(master->erasesize);
	81
	82	if (!buf)
	83	return -ENOMEM;
	84
1da177e4 LT	85	printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
	86	master->name, offset);
	87
	88	ret = master->read(master, offset,
	89	master->erasesize, &retlen, (void *)buf);
	90
	91	if (ret)
	92	goto out;
	93
	94	if (retlen != master->erasesize) {
	95	ret = -EIO;
	96	goto out;
	97	}
	98
	99	numslots = (master->erasesize / sizeof(struct fis_image_desc));
	100	for (i = 0; i < numslots; i++) {
9cff3372 JB	101	if (!memcmp(buf[i].name, "FIS directory", 14)) {
	102	/* This is apparently the FIS directory entry for the
	103	* FIS directory itself. The FIS directory size is
77a33135	104	* one erase block; if the buf[i].size field is
9cff3372 JB	105	* swab32(erasesize) then we know we are looking at
9cff3372 JB	106	* a byte swapped FIS directory - swap all the entries!
77a33135	107	* (NOTE: this is 'size' not 'data_length'; size is
9cff3372 JB	108	* the full size of the entry.)
9cff3372 JB	109	*/
7ca353a4 DW	110
	111	/* RedBoot can combine the FIS directory and
	112	config partitions into a single eraseblock;
	113	we assume wrong-endian if either the swapped
	114	'size' matches the eraseblock size precisely,
	115	or if the swapped size actually fits in an
	116	eraseblock while the unswapped size doesn't. */
	117	if (swab32(buf[i].size) == master->erasesize \|\|
	118	(buf[i].size > master->erasesize
	119	&& swab32(buf[i].size) < master->erasesize)) {
9cff3372	120	int j;
11192146 RW	121	/* Update numslots based on actual FIS directory size */
11192146 RW	122	numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc);
f33665d9 RW	123	for (j = 0; j < numslots; ++j) {
	124
	125	/* A single 0xff denotes a deleted entry.
	126	* Two of them in a row is the end of the table.
	127	*/
	128	if (buf[j].name[0] == 0xff) {
	129	if (buf[j].name[1] == 0xff) {
	130	break;
	131	} else {
	132	continue;
	133	}
	134	}
	135
9cff3372 JB	136	/* The unsigned long fields were written with the
	137	* wrong byte sex, name and pad have no byte sex.
	138	*/
77a33135 JB	139	swab32s(&buf[j].flash_base);
	140	swab32s(&buf[j].mem_base);
	141	swab32s(&buf[j].size);
	142	swab32s(&buf[j].entry_point);
	143	swab32s(&buf[j].data_length);
	144	swab32s(&buf[j].desc_cksum);
	145	swab32s(&buf[j].file_cksum);
9cff3372	146	}
7ca353a4	147	} else if (buf[i].size < master->erasesize) {
11192146 RW	148	/* Update numslots based on actual FIS directory size */
11192146 RW	149	numslots = buf[i].size / sizeof(struct fis_image_desc);
9cff3372	150	}
1da177e4	151	break;
9cff3372	152	}
1da177e4 LT	153	}
	154	if (i == numslots) {
	155	/* Didn't find it */
	156	printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
	157	master->name);
	158	ret = 0;
	159	goto out;
	160	}
	161
	162	for (i = 0; i < numslots; i++) {
	163	struct fis_list new_fl, *prev;
	164
f33665d9 RW	165	if (buf[i].name[0] == 0xff) {
	166	if (buf[i].name[1] == 0xff) {
	167	break;
	168	} else {
	169	continue;
	170	}
	171	}
1da177e4 LT	172	if (!redboot_checksum(&buf[i]))
	173	break;
	174
	175	new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
	176	namelen += strlen(buf[i].name)+1;
	177	if (!new_fl) {
	178	ret = -ENOMEM;
	179	goto out;
	180	}
	181	new_fl->img = &buf[i];
	182	if (fis_origin) {
	183	buf[i].flash_base -= fis_origin;
	184	} else {
	185	buf[i].flash_base &= master->size-1;
	186	}
	187
	188	/* I'm sure the JFFS2 code has done me permanent damage.
	189	* I now think the following is _normal_
	190	*/
	191	prev = &fl;
	192	while(prev && (prev)->img->flash_base < new_fl->img->flash_base)
	193	prev = &(*prev)->next;
	194	new_fl->next = *prev;
	195	*prev = new_fl;
	196
	197	nrparts++;
	198	}
	199	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	200	if (fl->img->flash_base) {
	201	nrparts++;
	202	nulllen = sizeof(nullstring);
	203	}
	204
	205	for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
	206	if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
	207	nrparts++;
	208	nulllen = sizeof(nullstring);
	209	}
	210	}
	211	#endif
95b93a0c	212	parts = kzalloc(sizeof(parts)nrparts + nulllen + namelen, GFP_KERNEL);
1da177e4 LT	213
	214	if (!parts) {
	215	ret = -ENOMEM;
	216	goto out;
	217	}
	218
1da177e4 LT	219	nullname = (char *)&parts[nrparts];
	220	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	221	if (nulllen > 0) {
	222	strcpy(nullname, nullstring);
	223	}
	224	#endif
	225	names = nullname + nulllen;
	226
	227	i=0;
	228
	229	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	230	if (fl->img->flash_base) {
	231	parts[0].name = nullname;
	232	parts[0].size = fl->img->flash_base;
	233	parts[0].offset = 0;
	234	i++;
	235	}
	236	#endif
	237	for ( ; i<nrparts; i++) {
	238	parts[i].size = fl->img->size;
	239	parts[i].offset = fl->img->flash_base;
	240	parts[i].name = names;
	241
	242	strcpy(names, fl->img->name);
	243	#ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
	244	if (!memcmp(names, "RedBoot", 8) \|\|
	245	!memcmp(names, "RedBoot config", 15) \|\|
	246	!memcmp(names, "FIS directory", 14)) {
	247	parts[i].mask_flags = MTD_WRITEABLE;
	248	}
	249	#endif
	250	names += strlen(names)+1;
	251
	252	#ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
	253	if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
	254	i++;
	255	parts[i].offset = parts[i-1].size + parts[i-1].offset;
	256	parts[i].size = fl->next->img->flash_base - parts[i].offset;
	257	parts[i].name = nullname;
	258	}
	259	#endif
	260	tmp_fl = fl;
	261	fl = fl->next;
	262	kfree(tmp_fl);
	263	}
	264	ret = nrparts;
	265	*pparts = parts;
	266	out:
	267	while (fl) {
	268	struct fis_list *old = fl;
	269	fl = fl->next;
	270	kfree(old);
	271	}
	272	vfree(buf);
	273	return ret;
	274	}
	275
	276	static struct mtd_part_parser redboot_parser = {
	277	.owner = THIS_MODULE,
	278	.parse_fn = parse_redboot_partitions,
	279	.name = "RedBoot",
	280	};
	281
	282	static int __init redboot_parser_init(void)
283	{
284	return register_mtd_parser(&redboot_parser);
285	}
286
287	static void __exit redboot_parser_exit(void)
288	{
289	deregister_mtd_parser(&redboot_parser);
290	}
291
292	module_init(redboot_parser_init);
293	module_exit(redboot_parser_exit);
294
295	MODULE_LICENSE("GPL");
44d1b980	296	MODULE_AUTHOR("David Woodhouse <[email protected]>");
1da177e4	297	MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");