/*====================================================================== drivers/mtd/afs.c: ARM Flash Layout/Partitioning Copyright (C) 2000 ARM Limited 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA This is access code for flashes using ARM's flash partitioning standards. $Id: afs.c,v 1.15 2005/11/07 11:14:19 gleixner Exp $ ======================================================================*/ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/init.h> #include <linux/mtd/mtd.h> #include <linux/mtd/map.h> #include <linux/mtd/partitions.h> struct footer_struct { u32 image_info_base; /* Address of first word of ImageFooter */ u32 image_start; /* Start of area reserved by this footer */ u32 signature; /* 'Magic' number proves it's a footer */ u32 type; /* Area type: ARM Image, SIB, customer */ u32 checksum; /* Just this structure */ }; struct image_info_struct { u32 bootFlags; /* Boot flags, compression etc. */ u32 imageNumber; /* Unique number, selects for boot etc. */ u32 loadAddress; /* Address program should be loaded to */ u32 length; /* Actual size of image */ u32 address; /* Image is executed from here */ char name[16]; /* Null terminated */ u32 headerBase; /* Flash Address of any stripped header */ u32 header_length; /* Length of header in memory */ u32 headerType; /* AIF, RLF, s-record etc. */ u32 checksum; /* Image checksum (inc. this struct) */ }; static u32 word_sum(void *words, int num) { u32 *p = words; u32 sum = 0; while (num--) sum += *p++; return sum; } static int afs_read_footer(struct mtd_info *mtd, u_int *img_start, u_int *iis_start, u_int off, u_int mask) { struct footer_struct fs; u_int ptr = off + mtd->erasesize - sizeof(fs); size_t sz; int ret; ret = mtd->read(mtd, ptr, sizeof(fs), &sz, (u_char *) &fs); if (ret >= 0 && sz != sizeof(fs)) ret = -EINVAL; if (ret < 0) { printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", ptr, ret); return ret; } ret = 1; /* * Does it contain the magic number? */ if (fs.signature != 0xa0ffff9f) ret = 0; /* * Check the checksum. */ if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff) ret = 0; /* * Don't touch the SIB. */ if (fs.type == 2) ret = 0; *iis_start = fs.image_info_base & mask; *img_start = fs.image_start & mask; /* * Check the image info base. This can not * be located after the footer structure. */ if (*iis_start >= ptr) ret = 0; /* * Check the start of this image. The image * data can not be located after this block. */ if (*img_start > off) ret = 0; return ret; } static int afs_read_iis(struct mtd_info *mtd, struct image_info_struct *iis, u_int ptr) { size_t sz; int ret, i; memset(iis, 0, sizeof(*iis)); ret = mtd->read(mtd, ptr, sizeof(*iis), &sz, (u_char *) iis); if (ret < 0) goto failed; if (sz != sizeof(*iis)) { ret = -EINVAL; goto failed; } ret = 0; /* * Validate the name - it must be NUL terminated. */ for (i = 0; i < sizeof(iis->name); i++) if (iis->name[i] == '\0') break; if (i < sizeof(iis->name)) ret = 1; return ret; failed: printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", ptr, ret); return ret; } static int parse_afs_partitions(struct mtd_info *mtd, struct mtd_partition **pparts, unsigned long origin) { struct mtd_partition *parts; u_int mask, off, idx, sz; int ret = 0; char *str; /* * This is the address mask; we use this to mask off out of * range address bits. */ mask = mtd->size - 1; /* * First, calculate the size of the array we need for the * partition information. We include in this the size of * the strings. */ for (idx = off = sz = 0; off < mtd->size; off += mtd->erasesize) { struct image_info_struct iis; u_int iis_ptr, img_ptr; ret = afs_read_footer(mtd, &img_ptr, &iis_ptr, off, mask); if (ret < 0) break; if (ret == 0) continue; ret = afs_read_iis(mtd, &iis, iis_ptr); if (ret < 0) break; if (ret == 0) continue; sz += sizeof(struct mtd_partition); sz += strlen(iis.name) + 1; idx += 1; } if (!sz) return ret; parts = kmalloc(sz, GFP_KERNEL); if (!parts) return -ENOMEM; memset(parts, 0, sz); str = (char *)(parts + idx); /* * Identify the partitions */ for (idx = off = 0; off < mtd->size; off += mtd->erasesize) { struct image_info_struct iis; u_int iis_ptr, img_ptr; /* Read the footer. */ ret = afs_read_footer(mtd, &img_ptr, &iis_ptr, off, mask); if (ret < 0) break; if (ret == 0) continue; /* Read the image info block */ ret = afs_read_iis(mtd, &iis, iis_ptr); if (ret < 0) break; if (ret == 0) continue; strcpy(str, iis.name); parts[idx].name = str; parts[idx].size = (iis.length + mtd->erasesize - 1) & ~(mtd->erasesize - 1); parts[idx].offset = img_ptr; parts[idx].mask_flags = 0; printk(" mtd%d: at 0x%08x, %5dKB, %8u, %s\n", idx, img_ptr, parts[idx].size / 1024, iis.imageNumber, str); idx += 1; str = str + strlen(iis.name) + 1; } if (!idx) { kfree(parts); parts = NULL; } *pparts = parts; return idx ? idx : ret; } static struct mtd_part_parser afs_parser = { .owner = THIS_MODULE, .parse_fn = parse_afs_partitions, .name = "afs", }; static int __init afs_parser_init(void) { return register_mtd_parser(&afs_parser); } static void __exit afs_parser_exit(void) { deregister_mtd_parser(&afs_parser); } module_init(afs_parser_init); module_exit(afs_parser_exit); MODULE_AUTHOR("ARM Ltd"); MODULE_DESCRIPTION("ARM Firmware Suite partition parser"); MODULE_LICENSE("GPL");