diff options
Diffstat (limited to 'drivers/mtd/redboot.c')
-rw-r--r-- | drivers/mtd/redboot.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/drivers/mtd/redboot.c b/drivers/mtd/redboot.c new file mode 100644 index 000000000..5da911ebd --- /dev/null +++ b/drivers/mtd/redboot.c @@ -0,0 +1,317 @@ +/* + * 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"); |