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1// SPDX-License-Identifier: GPL-2.0-or-later2/*======================================================================3 4 drivers/mtd/afs.c: ARM Flash Layout/Partitioning5 6 Copyright © 2000 ARM Limited7 Copyright (C) 2019 Linus Walleij8 9 10 This is access code for flashes using ARM's flash partitioning11 standards.12 13======================================================================*/14 15#include <linux/module.h>16#include <linux/types.h>17#include <linux/kernel.h>18#include <linux/slab.h>19#include <linux/string.h>20#include <linux/init.h>21 22#include <linux/mtd/mtd.h>23#include <linux/mtd/map.h>24#include <linux/mtd/partitions.h>25 26#define AFSV1_FOOTER_MAGIC 0xA0FFFF9F27#define AFSV2_FOOTER_MAGIC1 0x464C5348 /* "FLSH" */28#define AFSV2_FOOTER_MAGIC2 0x464F4F54 /* "FOOT" */29 30struct footer_v1 {31 u32 image_info_base; /* Address of first word of ImageFooter */32 u32 image_start; /* Start of area reserved by this footer */33 u32 signature; /* 'Magic' number proves it's a footer */34 u32 type; /* Area type: ARM Image, SIB, customer */35 u32 checksum; /* Just this structure */36};37 38struct image_info_v1 {39 u32 bootFlags; /* Boot flags, compression etc. */40 u32 imageNumber; /* Unique number, selects for boot etc. */41 u32 loadAddress; /* Address program should be loaded to */42 u32 length; /* Actual size of image */43 u32 address; /* Image is executed from here */44 char name[16]; /* Null terminated */45 u32 headerBase; /* Flash Address of any stripped header */46 u32 header_length; /* Length of header in memory */47 u32 headerType; /* AIF, RLF, s-record etc. */48 u32 checksum; /* Image checksum (inc. this struct) */49};50 51static u32 word_sum(void *words, int num)52{53 u32 *p = words;54 u32 sum = 0;55 56 while (num--)57 sum += *p++;58 59 return sum;60}61 62static u32 word_sum_v2(u32 *p, u32 num)63{64 u32 sum = 0;65 int i;66 67 for (i = 0; i < num; i++) {68 u32 val;69 70 val = p[i];71 if (val > ~sum)72 sum++;73 sum += val;74 }75 return ~sum;76}77 78static bool afs_is_v1(struct mtd_info *mtd, u_int off)79{80 /* The magic is 12 bytes from the end of the erase block */81 u_int ptr = off + mtd->erasesize - 12;82 u32 magic;83 size_t sz;84 int ret;85 86 ret = mtd_read(mtd, ptr, 4, &sz, (u_char *)&magic);87 if (ret < 0) {88 printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",89 ptr, ret);90 return false;91 }92 if (ret >= 0 && sz != 4)93 return false;94 95 return (magic == AFSV1_FOOTER_MAGIC);96}97 98static bool afs_is_v2(struct mtd_info *mtd, u_int off)99{100 /* The magic is the 8 last bytes of the erase block */101 u_int ptr = off + mtd->erasesize - 8;102 u32 foot[2];103 size_t sz;104 int ret;105 106 ret = mtd_read(mtd, ptr, 8, &sz, (u_char *)foot);107 if (ret < 0) {108 printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",109 ptr, ret);110 return false;111 }112 if (ret >= 0 && sz != 8)113 return false;114 115 return (foot[0] == AFSV2_FOOTER_MAGIC1 &&116 foot[1] == AFSV2_FOOTER_MAGIC2);117}118 119static int afs_parse_v1_partition(struct mtd_info *mtd,120 u_int off, struct mtd_partition *part)121{122 struct footer_v1 fs;123 struct image_info_v1 iis;124 u_int mask;125 /*126 * Static checks cannot see that we bail out if we have an error127 * reading the footer.128 */129 u_int iis_ptr;130 u_int img_ptr;131 u_int ptr;132 size_t sz;133 int ret;134 int i;135 136 /*137 * This is the address mask; we use this to mask off out of138 * range address bits.139 */140 mask = mtd->size - 1;141 142 ptr = off + mtd->erasesize - sizeof(fs);143 ret = mtd_read(mtd, ptr, sizeof(fs), &sz, (u_char *)&fs);144 if (ret >= 0 && sz != sizeof(fs))145 ret = -EINVAL;146 if (ret < 0) {147 printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",148 ptr, ret);149 return ret;150 }151 /*152 * Check the checksum.153 */154 if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff)155 return -EINVAL;156 157 /*158 * Hide the SIB (System Information Block)159 */160 if (fs.type == 2)161 return 0;162 163 iis_ptr = fs.image_info_base & mask;164 img_ptr = fs.image_start & mask;165 166 /*167 * Check the image info base. This can not168 * be located after the footer structure.169 */170 if (iis_ptr >= ptr)171 return 0;172 173 /*174 * Check the start of this image. The image175 * data can not be located after this block.176 */177 if (img_ptr > off)178 return 0;179 180 /* Read the image info block */181 memset(&iis, 0, sizeof(iis));182 ret = mtd_read(mtd, iis_ptr, sizeof(iis), &sz, (u_char *)&iis);183 if (ret < 0) {184 printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",185 iis_ptr, ret);186 return -EINVAL;187 }188 189 if (sz != sizeof(iis))190 return -EINVAL;191 192 /*193 * Validate the name - it must be NUL terminated.194 */195 for (i = 0; i < sizeof(iis.name); i++)196 if (iis.name[i] == '\0')197 break;198 if (i > sizeof(iis.name))199 return -EINVAL;200 201 part->name = kstrdup(iis.name, GFP_KERNEL);202 if (!part->name)203 return -ENOMEM;204 205 part->size = (iis.length + mtd->erasesize - 1) & ~(mtd->erasesize - 1);206 part->offset = img_ptr;207 part->mask_flags = 0;208 209 printk(" mtd: at 0x%08x, %5lluKiB, %8u, %s\n",210 img_ptr, part->size / 1024,211 iis.imageNumber, part->name);212 213 return 0;214}215 216static int afs_parse_v2_partition(struct mtd_info *mtd,217 u_int off, struct mtd_partition *part)218{219 u_int ptr;220 u32 footer[12];221 u32 imginfo[36];222 char *name;223 u32 version;224 u32 entrypoint;225 u32 attributes;226 u32 region_count;227 u32 block_start;228 u32 block_end;229 u32 crc;230 size_t sz;231 int ret;232 int i;233 int pad = 0;234 235 pr_debug("Parsing v2 partition @%08x-%08x\n",236 off, off + mtd->erasesize);237 238 /* First read the footer */239 ptr = off + mtd->erasesize - sizeof(footer);240 ret = mtd_read(mtd, ptr, sizeof(footer), &sz, (u_char *)footer);241 if ((ret < 0) || (ret >= 0 && sz != sizeof(footer))) {242 pr_err("AFS: mtd read failed at 0x%x: %d\n",243 ptr, ret);244 return -EIO;245 }246 name = (char *) &footer[0];247 version = footer[9];248 ptr = off + mtd->erasesize - sizeof(footer) - footer[8];249 250 pr_debug("found image \"%s\", version %08x, info @%08x\n",251 name, version, ptr);252 253 /* Then read the image information */254 ret = mtd_read(mtd, ptr, sizeof(imginfo), &sz, (u_char *)imginfo);255 if ((ret < 0) || (ret >= 0 && sz != sizeof(imginfo))) {256 pr_err("AFS: mtd read failed at 0x%x: %d\n",257 ptr, ret);258 return -EIO;259 }260 261 /* 32bit platforms have 4 bytes padding */262 crc = word_sum_v2(&imginfo[1], 34);263 if (!crc) {264 pr_debug("Padding 1 word (4 bytes)\n");265 pad = 1;266 } else {267 /* 64bit platforms have 8 bytes padding */268 crc = word_sum_v2(&imginfo[2], 34);269 if (!crc) {270 pr_debug("Padding 2 words (8 bytes)\n");271 pad = 2;272 }273 }274 if (crc) {275 pr_err("AFS: bad checksum on v2 image info: %08x\n", crc);276 return -EINVAL;277 }278 entrypoint = imginfo[pad];279 attributes = imginfo[pad+1];280 region_count = imginfo[pad+2];281 block_start = imginfo[20];282 block_end = imginfo[21];283 284 pr_debug("image entry=%08x, attr=%08x, regions=%08x, "285 "bs=%08x, be=%08x\n",286 entrypoint, attributes, region_count,287 block_start, block_end);288 289 for (i = 0; i < region_count; i++) {290 u32 region_load_addr = imginfo[pad + 3 + i*4];291 u32 region_size = imginfo[pad + 4 + i*4];292 u32 region_offset = imginfo[pad + 5 + i*4];293 u32 region_start;294 u32 region_end;295 296 pr_debug(" region %d: address: %08x, size: %08x, "297 "offset: %08x\n",298 i,299 region_load_addr,300 region_size,301 region_offset);302 303 region_start = off + region_offset;304 region_end = region_start + region_size;305 /* Align partition to end of erase block */306 region_end += (mtd->erasesize - 1);307 region_end &= ~(mtd->erasesize -1);308 pr_debug(" partition start = %08x, partition end = %08x\n",309 region_start, region_end);310 311 /* Create one partition per region */312 part->name = kstrdup(name, GFP_KERNEL);313 if (!part->name)314 return -ENOMEM;315 part->offset = region_start;316 part->size = region_end - region_start;317 part->mask_flags = 0;318 }319 320 return 0;321}322 323static int parse_afs_partitions(struct mtd_info *mtd,324 const struct mtd_partition **pparts,325 struct mtd_part_parser_data *data)326{327 struct mtd_partition *parts;328 u_int off, sz;329 int ret = 0;330 int i;331 332 /* Count the partitions by looping over all erase blocks */333 for (i = off = sz = 0; off < mtd->size; off += mtd->erasesize) {334 if (afs_is_v1(mtd, off)) {335 sz += sizeof(struct mtd_partition);336 i += 1;337 }338 if (afs_is_v2(mtd, off)) {339 sz += sizeof(struct mtd_partition);340 i += 1;341 }342 }343 344 if (!i)345 return 0;346 347 parts = kzalloc(sz, GFP_KERNEL);348 if (!parts)349 return -ENOMEM;350 351 /*352 * Identify the partitions353 */354 for (i = off = 0; off < mtd->size; off += mtd->erasesize) {355 if (afs_is_v1(mtd, off)) {356 ret = afs_parse_v1_partition(mtd, off, &parts[i]);357 if (ret)358 goto out_free_parts;359 i++;360 }361 if (afs_is_v2(mtd, off)) {362 ret = afs_parse_v2_partition(mtd, off, &parts[i]);363 if (ret)364 goto out_free_parts;365 i++;366 }367 }368 369 *pparts = parts;370 return i;371 372out_free_parts:373 while (--i >= 0)374 kfree(parts[i].name);375 kfree(parts);376 *pparts = NULL;377 return ret;378}379 380static const struct of_device_id mtd_parser_afs_of_match_table[] = {381 { .compatible = "arm,arm-firmware-suite" },382 {},383};384MODULE_DEVICE_TABLE(of, mtd_parser_afs_of_match_table);385 386static struct mtd_part_parser afs_parser = {387 .parse_fn = parse_afs_partitions,388 .name = "afs",389 .of_match_table = mtd_parser_afs_of_match_table,390};391module_mtd_part_parser(afs_parser);392 393MODULE_AUTHOR("ARM Ltd");394MODULE_DESCRIPTION("ARM Firmware Suite partition parser");395MODULE_LICENSE("GPL");396