drivers/mtd/parsers/afs.c - linux - Git at Google

 // 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);
 		i--;
 	}
 	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");
	// 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);
	i--;
	}
	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");