diff options
Diffstat (limited to 'drivers/mtd/afs.c')
| -rw-r--r-- | drivers/mtd/afs.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/mtd/afs.c b/drivers/mtd/afs.c new file mode 100644 index 000000000000..801e6c7d0892 --- /dev/null +++ b/drivers/mtd/afs.c @@ -0,0 +1,296 @@ +/*====================================================================== + + 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 1.13 2004/02/27 22:09:59 rmk 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, size; + + /* 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); + size = mtd->erasesize + off - img_ptr; + + /* + * In order to support JFFS2 partitions on this layout, + * we must lie to MTD about the real size of JFFS2 + * partitions; this ensures that the AFS flash footer + * won't be erased by JFFS2. Please ensure that your + * JFFS2 partitions are given image numbers between + * 1000 and 2000 inclusive. + */ + if (iis.imageNumber >= 1000 && iis.imageNumber < 2000) + size -= mtd->erasesize; + + parts[idx].name = str; + parts[idx].size = size; + 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"); |