/* * 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_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_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) { register_mtd_parser(&redboot_parser); return 0; } 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");