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			316 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			316 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Parse RedBoot-style Flash Image System (FIS) tables and
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|  * produce a Linux partition array to match.
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|  *
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|  * Copyright © 2001      Red Hat UK Limited
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|  * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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|  *
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/slab.h>
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| #include <linux/init.h>
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| #include <linux/vmalloc.h>
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| 
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| #include <linux/mtd/mtd.h>
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| #include <linux/mtd/partitions.h>
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| 
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| struct fis_image_desc {
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|     unsigned char name[16];      // Null terminated name
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|     uint32_t	  flash_base;    // Address within FLASH of image
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|     uint32_t	  mem_base;      // Address in memory where it executes
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|     uint32_t	  size;          // Length of image
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|     uint32_t	  entry_point;   // Execution entry point
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|     uint32_t	  data_length;   // Length of actual data
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|     unsigned char _pad[256-(16+7*sizeof(uint32_t))];
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|     uint32_t	  desc_cksum;    // Checksum over image descriptor
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|     uint32_t	  file_cksum;    // Checksum over image data
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| };
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| 
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| struct fis_list {
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| 	struct fis_image_desc *img;
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| 	struct fis_list *next;
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| };
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| 
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| static int directory = CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK;
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| module_param(directory, int, 0);
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| 
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| static inline int redboot_checksum(struct fis_image_desc *img)
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| {
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| 	/* RedBoot doesn't actually write the desc_cksum field yet AFAICT */
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| 	return 1;
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| }
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| 
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| static int parse_redboot_partitions(struct mtd_info *master,
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|                              struct mtd_partition **pparts,
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|                              unsigned long fis_origin)
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| {
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| 	int nrparts = 0;
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| 	struct fis_image_desc *buf;
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| 	struct mtd_partition *parts;
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| 	struct fis_list *fl = NULL, *tmp_fl;
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| 	int ret, i;
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| 	size_t retlen;
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| 	char *names;
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| 	char *nullname;
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| 	int namelen = 0;
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| 	int nulllen = 0;
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| 	int numslots;
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| 	unsigned long offset;
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| #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
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| 	static char nullstring[] = "unallocated";
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| #endif
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| 
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| 	if ( directory < 0 ) {
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| 		offset = master->size + directory * master->erasesize;
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| 		while (master->block_isbad && 
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| 		       master->block_isbad(master, offset)) {
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| 			if (!offset) {
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| 			nogood:
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| 				printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n");
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| 				return -EIO;
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| 			}
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| 			offset -= master->erasesize;
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| 		}
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| 	} else {
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| 		offset = directory * master->erasesize;
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| 		while (master->block_isbad && 
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| 		       master->block_isbad(master, offset)) {
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| 			offset += master->erasesize;
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| 			if (offset == master->size)
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| 				goto nogood;
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| 		}
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| 	}
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| 	buf = vmalloc(master->erasesize);
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| 
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| 	if (!buf)
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| 		return -ENOMEM;
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| 
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| 	printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
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| 	       master->name, offset);
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| 
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| 	ret = master->read(master, offset,
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| 			   master->erasesize, &retlen, (void *)buf);
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| 
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| 	if (ret)
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| 		goto out;
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| 
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| 	if (retlen != master->erasesize) {
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| 		ret = -EIO;
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| 		goto out;
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| 	}
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| 
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| 	numslots = (master->erasesize / sizeof(struct fis_image_desc));
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| 	for (i = 0; i < numslots; i++) {
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| 		if (!memcmp(buf[i].name, "FIS directory", 14)) {
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| 			/* This is apparently the FIS directory entry for the
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| 			 * FIS directory itself.  The FIS directory size is
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| 			 * one erase block; if the buf[i].size field is
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| 			 * swab32(erasesize) then we know we are looking at
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| 			 * a byte swapped FIS directory - swap all the entries!
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| 			 * (NOTE: this is 'size' not 'data_length'; size is
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| 			 * the full size of the entry.)
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| 			 */
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| 
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| 			/* RedBoot can combine the FIS directory and
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| 			   config partitions into a single eraseblock;
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| 			   we assume wrong-endian if either the swapped
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| 			   'size' matches the eraseblock size precisely,
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| 			   or if the swapped size actually fits in an
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| 			   eraseblock while the unswapped size doesn't. */
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| 			if (swab32(buf[i].size) == master->erasesize ||
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| 			    (buf[i].size > master->erasesize
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| 			     && swab32(buf[i].size) < master->erasesize)) {
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| 				int j;
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| 				/* Update numslots based on actual FIS directory size */
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| 				numslots = swab32(buf[i].size) / sizeof (struct fis_image_desc);
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| 				for (j = 0; j < numslots; ++j) {
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| 
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| 					/* A single 0xff denotes a deleted entry.
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| 					 * Two of them in a row is the end of the table.
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| 					 */
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| 					if (buf[j].name[0] == 0xff) {
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| 				  		if (buf[j].name[1] == 0xff) {
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| 							break;
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| 						} else {
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| 							continue;
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| 						}
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| 					}
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| 
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| 					/* The unsigned long fields were written with the
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| 					 * wrong byte sex, name and pad have no byte sex.
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| 					 */
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| 					swab32s(&buf[j].flash_base);
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| 					swab32s(&buf[j].mem_base);
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| 					swab32s(&buf[j].size);
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| 					swab32s(&buf[j].entry_point);
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| 					swab32s(&buf[j].data_length);
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| 					swab32s(&buf[j].desc_cksum);
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| 					swab32s(&buf[j].file_cksum);
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| 				}
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| 			} else if (buf[i].size < master->erasesize) {
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| 				/* Update numslots based on actual FIS directory size */
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| 				numslots = buf[i].size / sizeof(struct fis_image_desc);
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| 			}
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| 			break;
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| 		}
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| 	}
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| 	if (i == numslots) {
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| 		/* Didn't find it */
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| 		printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
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| 		       master->name);
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| 		ret = 0;
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| 		goto out;
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| 	}
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| 
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| 	for (i = 0; i < numslots; i++) {
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| 		struct fis_list *new_fl, **prev;
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| 
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| 		if (buf[i].name[0] == 0xff) {
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| 			if (buf[i].name[1] == 0xff) {
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| 				break;
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| 			} else {
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| 				continue;
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| 			}
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| 		}
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| 		if (!redboot_checksum(&buf[i]))
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| 			break;
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| 
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| 		new_fl = kmalloc(sizeof(struct fis_list), GFP_KERNEL);
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| 		namelen += strlen(buf[i].name)+1;
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| 		if (!new_fl) {
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| 			ret = -ENOMEM;
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| 			goto out;
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| 		}
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| 		new_fl->img = &buf[i];
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|                 if (fis_origin) {
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|                         buf[i].flash_base -= fis_origin;
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|                 } else {
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|                         buf[i].flash_base &= master->size-1;
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|                 }
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| 
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| 		/* I'm sure the JFFS2 code has done me permanent damage.
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| 		 * I now think the following is _normal_
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| 		 */
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| 		prev = &fl;
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| 		while(*prev && (*prev)->img->flash_base < new_fl->img->flash_base)
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| 			prev = &(*prev)->next;
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| 		new_fl->next = *prev;
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| 		*prev = new_fl;
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| 
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| 		nrparts++;
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| 	}
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| #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
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| 	if (fl->img->flash_base) {
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| 		nrparts++;
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| 		nulllen = sizeof(nullstring);
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| 	}
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| 
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| 	for (tmp_fl = fl; tmp_fl->next; tmp_fl = tmp_fl->next) {
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| 		if (tmp_fl->img->flash_base + tmp_fl->img->size + master->erasesize <= tmp_fl->next->img->flash_base) {
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| 			nrparts++;
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| 			nulllen = sizeof(nullstring);
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| 		}
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| 	}
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| #endif
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| 	parts = kzalloc(sizeof(*parts)*nrparts + nulllen + namelen, GFP_KERNEL);
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| 
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| 	if (!parts) {
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| 		ret = -ENOMEM;
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| 		goto out;
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| 	}
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| 
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| 	nullname = (char *)&parts[nrparts];
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| #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
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| 	if (nulllen > 0) {
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| 		strcpy(nullname, nullstring);
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| 	}
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| #endif
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| 	names = nullname + nulllen;
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| 
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| 	i=0;
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| 
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| #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
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| 	if (fl->img->flash_base) {
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| 	       parts[0].name = nullname;
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| 	       parts[0].size = fl->img->flash_base;
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| 	       parts[0].offset = 0;
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| 		i++;
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| 	}
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| #endif
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| 	for ( ; i<nrparts; i++) {
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| 		parts[i].size = fl->img->size;
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| 		parts[i].offset = fl->img->flash_base;
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| 		parts[i].name = names;
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| 
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| 		strcpy(names, fl->img->name);
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| #ifdef CONFIG_MTD_REDBOOT_PARTS_READONLY
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| 		if (!memcmp(names, "RedBoot", 8) ||
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| 				!memcmp(names, "RedBoot config", 15) ||
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| 				!memcmp(names, "FIS directory", 14)) {
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| 			parts[i].mask_flags = MTD_WRITEABLE;
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| 		}
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| #endif
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| 		names += strlen(names)+1;
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| 
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| #ifdef CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED
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| 		if(fl->next && fl->img->flash_base + fl->img->size + master->erasesize <= fl->next->img->flash_base) {
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| 			i++;
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| 			parts[i].offset = parts[i-1].size + parts[i-1].offset;
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| 			parts[i].size = fl->next->img->flash_base - parts[i].offset;
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| 			parts[i].name = nullname;
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| 		}
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| #endif
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| 		tmp_fl = fl;
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| 		fl = fl->next;
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| 		kfree(tmp_fl);
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| 	}
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| 	ret = nrparts;
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| 	*pparts = parts;
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|  out:
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| 	while (fl) {
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| 		struct fis_list *old = fl;
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| 		fl = fl->next;
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| 		kfree(old);
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| 	}
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| 	vfree(buf);
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| 	return ret;
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| }
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| 
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| static struct mtd_part_parser redboot_parser = {
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| 	.owner = THIS_MODULE,
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| 	.parse_fn = parse_redboot_partitions,
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| 	.name = "RedBoot",
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| };
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| 
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| static int __init redboot_parser_init(void)
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| {
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| 	return register_mtd_parser(&redboot_parser);
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| }
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| 
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| static void __exit redboot_parser_exit(void)
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| {
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| 	deregister_mtd_parser(&redboot_parser);
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| }
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| 
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| module_init(redboot_parser_init);
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| module_exit(redboot_parser_exit);
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| 
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| MODULE_LICENSE("GPL");
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| MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
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| MODULE_DESCRIPTION("Parsing code for RedBoot Flash Image System (FIS) tables");
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