diff options
Diffstat (limited to 'drivers/mtd/parsers/afs.c')
| -rw-r--r-- | drivers/mtd/parsers/afs.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/mtd/parsers/afs.c b/drivers/mtd/parsers/afs.c new file mode 100644 index 000000000..26116694c --- /dev/null +++ b/drivers/mtd/parsers/afs.c @@ -0,0 +1,395 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*====================================================================== + + drivers/mtd/afs.c: ARM Flash Layout/Partitioning + + Copyright © 2000 ARM Limited + Copyright (C) 2019 Linus Walleij + + + This is access code for flashes using ARM's flash partitioning + standards. + +======================================================================*/ + +#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> + +#define AFSV1_FOOTER_MAGIC 0xA0FFFF9F +#define AFSV2_FOOTER_MAGIC1 0x464C5348 /* "FLSH" */ +#define AFSV2_FOOTER_MAGIC2 0x464F4F54 /* "FOOT" */ + +struct footer_v1 { + 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_v1 { + 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 u32 word_sum_v2(u32 *p, u32 num) +{ + u32 sum = 0; + int i; + + for (i = 0; i < num; i++) { + u32 val; + + val = p[i]; + if (val > ~sum) + sum++; + sum += val; + } + return ~sum; +} + +static bool afs_is_v1(struct mtd_info *mtd, u_int off) +{ + /* The magic is 12 bytes from the end of the erase block */ + u_int ptr = off + mtd->erasesize - 12; + u32 magic; + size_t sz; + int ret; + + ret = mtd_read(mtd, ptr, 4, &sz, (u_char *)&magic); + if (ret < 0) { + printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", + ptr, ret); + return false; + } + if (ret >= 0 && sz != 4) + return false; + + return (magic == AFSV1_FOOTER_MAGIC); +} + +static bool afs_is_v2(struct mtd_info *mtd, u_int off) +{ + /* The magic is the 8 last bytes of the erase block */ + u_int ptr = off + mtd->erasesize - 8; + u32 foot[2]; + size_t sz; + int ret; + + ret = mtd_read(mtd, ptr, 8, &sz, (u_char *)foot); + if (ret < 0) { + printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", + ptr, ret); + return false; + } + if (ret >= 0 && sz != 8) + return false; + + return (foot[0] == AFSV2_FOOTER_MAGIC1 && + foot[1] == AFSV2_FOOTER_MAGIC2); +} + +static int afs_parse_v1_partition(struct mtd_info *mtd, + u_int off, struct mtd_partition *part) +{ + struct footer_v1 fs; + struct image_info_v1 iis; + u_int mask; + /* + * Static checks cannot see that we bail out if we have an error + * reading the footer. + */ + u_int iis_ptr; + u_int img_ptr; + u_int ptr; + size_t sz; + int ret; + int i; + + /* + * This is the address mask; we use this to mask off out of + * range address bits. + */ + mask = mtd->size - 1; + + ptr = off + mtd->erasesize - sizeof(fs); + 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; + } + /* + * Check the checksum. + */ + if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff) + return -EINVAL; + + /* + * Hide the SIB (System Information Block) + */ + if (fs.type == 2) + return 0; + + iis_ptr = fs.image_info_base & mask; + img_ptr = fs.image_start & mask; + + /* + * Check the image info base. This can not + * be located after the footer structure. + */ + if (iis_ptr >= ptr) + return 0; + + /* + * Check the start of this image. The image + * data can not be located after this block. + */ + if (img_ptr > off) + return 0; + + /* Read the image info block */ + memset(&iis, 0, sizeof(iis)); + ret = mtd_read(mtd, iis_ptr, sizeof(iis), &sz, (u_char *)&iis); + if (ret < 0) { + printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n", + iis_ptr, ret); + return -EINVAL; + } + + if (sz != sizeof(iis)) + return -EINVAL; + + /* + * 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)) + return -EINVAL; + + part->name = kstrdup(iis.name, GFP_KERNEL); + if (!part->name) + return -ENOMEM; + + part->size = (iis.length + mtd->erasesize - 1) & ~(mtd->erasesize - 1); + part->offset = img_ptr; + part->mask_flags = 0; + + printk(" mtd: at 0x%08x, %5lluKiB, %8u, %s\n", + img_ptr, part->size / 1024, + iis.imageNumber, part->name); + + return 0; +} + +static int afs_parse_v2_partition(struct mtd_info *mtd, + u_int off, struct mtd_partition *part) +{ + u_int ptr; + u32 footer[12]; + u32 imginfo[36]; + char *name; + u32 version; + u32 entrypoint; + u32 attributes; + u32 region_count; + u32 block_start; + u32 block_end; + u32 crc; + size_t sz; + int ret; + int i; + int pad = 0; + + pr_debug("Parsing v2 partition @%08x-%08x\n", + off, off + mtd->erasesize); + + /* First read the footer */ + ptr = off + mtd->erasesize - sizeof(footer); + ret = mtd_read(mtd, ptr, sizeof(footer), &sz, (u_char *)footer); + if ((ret < 0) || (ret >= 0 && sz != sizeof(footer))) { + pr_err("AFS: mtd read failed at 0x%x: %d\n", + ptr, ret); + return -EIO; + } + name = (char *) &footer[0]; + version = footer[9]; + ptr = off + mtd->erasesize - sizeof(footer) - footer[8]; + + pr_debug("found image \"%s\", version %08x, info @%08x\n", + name, version, ptr); + + /* Then read the image information */ + ret = mtd_read(mtd, ptr, sizeof(imginfo), &sz, (u_char *)imginfo); + if ((ret < 0) || (ret >= 0 && sz != sizeof(imginfo))) { + pr_err("AFS: mtd read failed at 0x%x: %d\n", + ptr, ret); + return -EIO; + } + + /* 32bit platforms have 4 bytes padding */ + crc = word_sum_v2(&imginfo[1], 34); + if (!crc) { + pr_debug("Padding 1 word (4 bytes)\n"); + pad = 1; + } else { + /* 64bit platforms have 8 bytes padding */ + crc = word_sum_v2(&imginfo[2], 34); + if (!crc) { + pr_debug("Padding 2 words (8 bytes)\n"); + pad = 2; + } + } + if (crc) { + pr_err("AFS: bad checksum on v2 image info: %08x\n", crc); + return -EINVAL; + } + entrypoint = imginfo[pad]; + attributes = imginfo[pad+1]; + region_count = imginfo[pad+2]; + block_start = imginfo[20]; + block_end = imginfo[21]; + + pr_debug("image entry=%08x, attr=%08x, regions=%08x, " + "bs=%08x, be=%08x\n", + entrypoint, attributes, region_count, + block_start, block_end); + + for (i = 0; i < region_count; i++) { + u32 region_load_addr = imginfo[pad + 3 + i*4]; + u32 region_size = imginfo[pad + 4 + i*4]; + u32 region_offset = imginfo[pad + 5 + i*4]; + u32 region_start; + u32 region_end; + + pr_debug(" region %d: address: %08x, size: %08x, " + "offset: %08x\n", + i, + region_load_addr, + region_size, + region_offset); + + region_start = off + region_offset; + region_end = region_start + region_size; + /* Align partition to end of erase block */ + region_end += (mtd->erasesize - 1); + region_end &= ~(mtd->erasesize -1); + pr_debug(" partition start = %08x, partition end = %08x\n", + region_start, region_end); + + /* Create one partition per region */ + part->name = kstrdup(name, GFP_KERNEL); + if (!part->name) + return -ENOMEM; + part->offset = region_start; + part->size = region_end - region_start; + part->mask_flags = 0; + } + + return 0; +} + +static int parse_afs_partitions(struct mtd_info *mtd, + const struct mtd_partition **pparts, + struct mtd_part_parser_data *data) +{ + struct mtd_partition *parts; + u_int off, sz; + int ret = 0; + int i; + + /* Count the partitions by looping over all erase blocks */ + for (i = off = sz = 0; off < mtd->size; off += mtd->erasesize) { + if (afs_is_v1(mtd, off)) { + sz += sizeof(struct mtd_partition); + i += 1; + } + if (afs_is_v2(mtd, off)) { + sz += sizeof(struct mtd_partition); + i += 1; + } + } + + if (!i) + return 0; + + parts = kzalloc(sz, GFP_KERNEL); + if (!parts) + return -ENOMEM; + + /* + * Identify the partitions + */ + for (i = off = 0; off < mtd->size; off += mtd->erasesize) { + if (afs_is_v1(mtd, off)) { + ret = afs_parse_v1_partition(mtd, off, &parts[i]); + if (ret) + goto out_free_parts; + i++; + } + if (afs_is_v2(mtd, off)) { + ret = afs_parse_v2_partition(mtd, off, &parts[i]); + if (ret) + goto out_free_parts; + i++; + } + } + + *pparts = parts; + return i; + +out_free_parts: + while (--i >= 0) + kfree(parts[i].name); + kfree(parts); + *pparts = NULL; + return ret; +} + +static const struct of_device_id mtd_parser_afs_of_match_table[] = { + { .compatible = "arm,arm-firmware-suite" }, + {}, +}; +MODULE_DEVICE_TABLE(of, mtd_parser_afs_of_match_table); + +static struct mtd_part_parser afs_parser = { + .parse_fn = parse_afs_partitions, + .name = "afs", + .of_match_table = mtd_parser_afs_of_match_table, +}; +module_mtd_part_parser(afs_parser); + +MODULE_AUTHOR("ARM Ltd"); +MODULE_DESCRIPTION("ARM Firmware Suite partition parser"); +MODULE_LICENSE("GPL"); |