ARM MTD AFS v2 partition support

This simplifies the AFS partition parsing to make the code more straight-forward and readable.

Before this patch the code tried to calculate the memory required to hold the partition info by adding up the sizes of the strings of the names and adding that to a single memory allocation, indexing the name pointers in front of the struct mtd_partition allocations so all allocated data was in one chunk.

This is overzealous. Instead use kstrdup and bail out, kfree():ing the memory used for MTD partitions and names alike on the errorpath.

In the process rename the index variable from idx to i.

Cc Ryan Harkin <[email protected]>

Cc Liviu Dudau <[email protected]>

Signed-off-by Linus Walleij <[email protected]>

---
 drivers/mtd/afs.c | 67 ++++++++++++++++++++++++++-----------------------------
 1 file changed, 32 insertions(+), 35 deletions(-)

drivers/mtd/afs.c +2 -2

index a1eea50ce180..9e6089615f16 100644
@@ -166,9 +166,9 @@ static int parse_afs_partitions(struct mtd_info *mtd,
 				struct mtd_part_parser_data *data)
 {
 	struct mtd_partition *parts;
-	u_int mask, off, idx, sz;
+	u_int mask, off, sz;
 	int ret = 0;
-	char *str;
+	int i;
 
 	/*
 	 * This is the address mask; we use this to mask off out of

drivers/mtd/afs.c +7 -17

-	for (idx = off = sz = 0; off < mtd->size; off += mtd->erasesize) {
-		struct image_info_v1 iis;
+	for (i = off = sz = 0; off < mtd->size; off += mtd->erasesize) {
 		u_int iis_ptr, img_ptr;
 
 		ret = afs_read_footer_v1(mtd, &img_ptr, &iis_ptr, off, mask);
 		if (ret < 0)
-			break;
+			return ret;
 		if (ret) {
-			ret = afs_read_iis_v1(mtd, &iis, iis_ptr);
-			if (ret < 0)
-				break;
-			if (ret == 0)
-				continue;
-
 			sz += sizeof(struct mtd_partition);
-			sz += strlen(iis.name) + 1;
-			idx += 1;
+			i += 1;
 		}
 	}
 
-	if (!sz)
-		return ret;
+	if (!i)
+		return 0;
 
 	parts = kzalloc(sz, GFP_KERNEL);
 	if (!parts)
 		return -ENOMEM;
 
-	str = (char *)(parts + idx);
-
 	/*
 	 * Identify the partitions
 	 */
-	for (idx = off = 0; off < mtd->size; off += mtd->erasesize) {
+	for (i = off = 0; off < mtd->size; off += mtd->erasesize) {
 		struct image_info_v1 iis;
 		u_int iis_ptr, img_ptr;
 
 		/* Read the footer. */
 		ret = afs_read_footer_v1(mtd, &img_ptr, &iis_ptr, off, mask);
 		if (ret < 0)
-			break;
+			goto out_free_parts;
 		if (ret == 0)
 			continue;
 

drivers/mtd/afs.c +21 -14

+		if (!parts[i].name) {
+			ret = -ENOMEM;
+			goto out_free_parts;
+		}
 
-		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;
+		parts[i].size		= (iis.length + mtd->erasesize - 1) & ~(mtd->erasesize - 1);
+		parts[i].offset	= img_ptr;
+		parts[i].mask_flags	= 0;
 
 		printk("  mtd%d: at 0x%08x, %5lluKiB, %8u, %s\n",
-			idx, img_ptr, parts[idx].size / 1024,
-			iis.imageNumber, str);
-
-		idx += 1;
-		str = str + strlen(iis.name) + 1;
-	}
+			i, img_ptr, parts[i].size / 1024,
+			iis.imageNumber, parts[i].name);
 
-	if (!idx) {
-		kfree(parts);
-		parts = NULL;
+		i += 1;
 	}
 
 	*pparts = parts;
-	return idx ? idx : ret;
+	return i;
+
+out_free_parts:
+	while (i >= 0) {
+		if (parts[i].name)
+			kfree(parts[i].name);
+		i--;
+	}
+	kfree(parts);
+	*pparts = NULL;
+	return ret;
 }
 
 static struct mtd_part_parser afs_parser = {

Signature · 1 line

2.4.3

Instead of reading out the AFS footers twice, create a separate function to just check if there is a footer or not. Rids a few local variables and prepare us to join the actual parser into one function.

Cc Ryan Harkin <[email protected]>

Cc Liviu Dudau <[email protected]>

Signed-off-by Linus Walleij <[email protected]>

---
 drivers/mtd/afs.c | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

drivers/mtd/afs.c +21 -5

index 9e6089615f16..2307f54195f5 100644
@@ -68,6 +68,26 @@ static u32 word_sum(void *words, int num)
 	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 int
 afs_read_footer_v1(struct mtd_info *mtd, u_int *img_start, u_int *iis_start,
 		   u_int off, u_int mask)

@@ -176,18 +196,9 @@ static int parse_afs_partitions(struct mtd_info *mtd,
 	 */
 	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.
-	 */
+	/* Count the partitions by looping over all erase blocks */
 	for (i = off = sz = 0; off < mtd->size; off += mtd->erasesize) {

This breaks out the parsing of v1 partitions so we can later add a v2 partition parser.

Cc Ryan Harkin <[email protected]>

Cc Liviu Dudau <[email protected]>

Signed-off-by Linus Walleij <[email protected]>

---
 drivers/mtd/afs.c | 88 +++++++++++++++++++++++++++++++------------------------
 1 file changed, 50 insertions(+), 38 deletions(-)

drivers/mtd/afs.c +2 -5

index 2307f54195f5..ace27f447abc 100644
@@ -181,14 +181,18 @@ afs_read_iis_v1(struct mtd_info *mtd, struct image_info_v1 *iis, u_int ptr)
 	return ret;
 }
 
-static int parse_afs_partitions(struct mtd_info *mtd,
-				struct mtd_partition **pparts,
-				struct mtd_part_parser_data *data)
+static int afs_parse_v1_partition(struct mtd_info *mtd,
+				  u_int off, struct mtd_partition *part)
 {
-	struct mtd_partition *parts;
-	u_int mask, off, sz;

This simplifies the code by factoring in the image footer parsing into the single function parsing the AFSv1 partitions.

Cc Ryan Harkin <[email protected]>

Cc Liviu Dudau <[email protected]>

Signed-off-by Linus Walleij <[email protected]>

---
 drivers/mtd/afs.c | 98 ++++++++++++++++++++++---------------------------------
 1 file changed, 39 insertions(+), 59 deletions(-)

drivers/mtd/afs.c +7 -59

index ace27f447abc..cdee8295d4c0 100644
@@ -89,63 +89,6 @@ static bool afs_is_v1(struct mtd_info *mtd, u_int off)
 }
 
 static int
-afs_read_footer_v1(struct mtd_info *mtd, u_int *img_start, u_int *iis_start,
-		   u_int off, u_int mask)
-{
-	struct footer_v1 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;
-	}
-
-	/*
-	 * Does it contain the magic number?
-	 */
-	if (fs.signature != AFSV1_FOOTER_MAGIC)
-		return 0;
-
-	/*
-	 * Check the checksum.
-	 */
-	if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff)
-		return 0;
-
-	/*
-	 * Don't touch the SIB.
-	 */
-	if (fs.type == 2)
-		return 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)
-		return 0;
-
-	/*
-	 * Check the start of this image.  The image
-	 * data can not be located after this block.
-	 */
-	if (*img_start > off)
-		return 0;
-
-	return 1;
-}
-
-static int
 afs_read_iis_v1(struct mtd_info *mtd, struct image_info_v1 *iis, u_int ptr)
 {
 	size_t sz;

@@ -184,6 +127,7 @@ afs_read_iis_v1(struct mtd_info *mtd, struct image_info_v1 *iis, u_int ptr)
 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;
 	/*

@@ -192,6 +136,8 @@ static int afs_parse_v1_partition(struct mtd_info *mtd,
 	 */
 	u_int uninitialized_var(iis_ptr);
 	u_int uninitialized_var(img_ptr);
+	u_int ptr;
+	size_t sz;
 	int ret;
 
 	/*

@@ -200,9 +146,43 @@ static int afs_parse_v1_partition(struct mtd_info *mtd,
 	 */
 	mask = mtd->size - 1;
 
-	ret = afs_read_footer_v1(mtd, &img_ptr, &iis_ptr, off, mask);
-	if (ret < 0)
+	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;

drivers/mtd/afs.c +23 -0

+
+	/*
+	 * 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 */
 	ret = afs_read_iis_v1(mtd, &iis, iis_ptr);

Signature · 1 line

2.4.3

Factor the IIS (Image Information Structure) reading into the partition parser, giving us a single, clean partition parser function.

Cc Ryan Harkin <[email protected]>

Cc Liviu Dudau <[email protected]>

Signed-off-by Linus Walleij <[email protected]>

---
 drivers/mtd/afs.c | 59 +++++++++++++++++++------------------------------------
 1 file changed, 20 insertions(+), 39 deletions(-)

drivers/mtd/afs.c +9 -39

index cdee8295d4c0..1ce6842c917c 100644
@@ -88,42 +88,6 @@ static bool afs_is_v1(struct mtd_info *mtd, u_int off)
 	return (magic == AFSV1_FOOTER_MAGIC);
 }
 
-static int
-afs_read_iis_v1(struct mtd_info *mtd, struct image_info_v1 *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 afs_parse_v1_partition(struct mtd_info *mtd,
 				  u_int off, struct mtd_partition *part)
 {

@@ -139,6 +103,7 @@ static int afs_parse_v1_partition(struct mtd_info *mtd,
 	u_int ptr;
 	size_t sz;
 	int ret;
+	int i;
 
 	/*
 	 * This is the address mask; we use this to mask off out of

@@ -185,9 +150,25 @@ static int afs_parse_v1_partition(struct mtd_info *mtd,
 		return 0;
 
 	/* Read the image info block */
-	ret = afs_read_iis_v1(mtd, &iis, iis_ptr);
-	if (ret < 0)
-		return ret;
+	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;
+	}
+

The AFS v2 partition type appear in later ARM reference designs such as RealView, Versatile Express and the 64bit Juno Development Platform.

The image informations is padded with a 32bit word (4 bytes) on the 32bit platforms and a 64bit word (8 bytes) on the 64bit platforms. The boot monitor source code gives at hand that this is because the first entry in the struct mapped over the image information is a "next" pointer for a linked list, filled in by firmware after reading in the info block, and always zero in the flash. We adjust padding by checking what padding gives the right checksum.

This was tested on:
- Integrator/AP (v1 partitions)
- RealView PB11MPCore (v2 32bit partitions)
- Juno Development System (v2 64bit partitions)

All systems display the images in flash very nicely as separate partitions, e.g on Juno:

4 afs partitions found on MTD device 8000000.flash Creating 4 MTD partitions on "8000000.flash":
0x000000040000-0x0000000c0000 : "fip" 0x000000ec0000-0x0000018c0000 : "Image" 0x000000f00000-0x000000f40000 : "juno" 0x000003ec0000-0x000003f00000 : "bl1"

Cc Ryan Harkin <[email protected]>

Cc Liviu Dudau <[email protected]>

Signed-off-by Linus Walleij <[email protected]>

---
 drivers/mtd/afs.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 157 insertions(+), 1 deletion(-)

drivers/mtd/afs.c +0 -0

index 1ce6842c917c..e46b035bf4d2 100644

drivers/mtd/afs.c +150 -0

    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

@@ -35,6 +36,8 @@
 #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  */

@@ -68,6 +71,22 @@ static u32 word_sum(void *words, int num)
 	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 */

@@ -88,6 +107,27 @@ static bool afs_is_v1(struct mtd_info *mtd, u_int off)
 	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)
 {

@@ -185,6 +225,113 @@ static int afs_parse_v1_partition(struct mtd_info *mtd,
 	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,
 				struct mtd_partition **pparts,
 				struct mtd_part_parser_data *data)

@@ -200,6 +347,10 @@ static int parse_afs_partitions(struct mtd_info *mtd,
 			sz += sizeof(struct mtd_partition);
 			i += 1;
 		}
+		if (afs_is_v2(mtd, off)) {
+			sz += sizeof(struct mtd_partition);
+			i += 1;
+		}
 	}
 
 	if (!i)

@@ -213,13 +364,18 @@ static int parse_afs_partitions(struct mtd_info *mtd,
 	 * Identify the partitions

The AFS v2 partition type appear in later ARM reference designs such as RealView, Versatile Express and the 64bit Juno Development Platform.

The image informations is padded with a 32bit word (4 bytes) on the 32bit platforms and a 64bit word (8 bytes) on the 64bit platforms. The boot monitor source code gives at hand that this is because the first entry in the struct mapped over the image information is a "next" pointer for a linked list, filled in by firmware after reading in the info block, and always zero in the flash. We adjust padding by checking what padding gives the right checksum.

This was tested on:
- Integrator/AP (v1 partitions)
- RealView PB11MPCore (v2 32bit partitions)
- Juno Development System (v2 64bit partitions)

All systems display the images in flash very nicely as separate partitions, e.g on Juno:

4 afs partitions found on MTD device 8000000.flash Creating 4 MTD partitions on "8000000.flash":
0x000000040000-0x0000000c0000 : "fip" 0x000000ec0000-0x0000018c0000 : "Image" 0x000000f00000-0x000000f40000 : "juno" 0x000003ec0000-0x000003f00000 : "bl1"

Cc Ryan Harkin <[email protected]>

Cc Liviu Dudau <[email protected]>

Signed-off-by Linus Walleij <[email protected]>

---
 drivers/mtd/afs.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 157 insertions(+), 1 deletion(-)

drivers/mtd/afs.c +3 -0

index 1ce6842c917c..e46b035bf4d2 100644
@@ -3,6 +3,7 @@
     drivers/mtd/afs.c: ARM Flash Layout/Partitioning
 
     Copyright ? 2000 ARM Limited
+    Copyright (C) 2015 Linus Walleij
 
    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

@@ -35,6 +36,8 @@
 #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  */

drivers/mtd/afs.c +15 -0

+{
+	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 */

drivers/mtd/afs.c +5 -0

+	u32 foot[2];
+	size_t sz;
+	int ret;
+
+	ret = mtd_read(mtd, ptr, 8, &sz, (u_char *)foot);

drivers/mtd/afs.c +2 -0

+}
+
 static int afs_parse_v1_partition(struct mtd_info *mtd,
 				  u_int off, struct mtd_partition *part)
 {

drivers/mtd/afs.c +31 -0

+	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);
+

drivers/mtd/afs.c +12 -0

+		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);

drivers/mtd/afs.c +20 -1

+		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,
 				struct mtd_partition **pparts,
 				struct mtd_part_parser_data *data)

@@ -200,6 +347,10 @@ static int parse_afs_partitions(struct mtd_info *mtd,
 			sz += sizeof(struct mtd_partition);
 			i += 1;
 		}
+		if (afs_is_v2(mtd, off)) {
+			sz += sizeof(struct mtd_partition);
+			i += 1;
+		}
 	}
 
 	if (!i)

@@ -213,13 +364,18 @@ static int parse_afs_partitions(struct mtd_info *mtd,
 	 * 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;

Signature · 1 line

2.4.3

Years ago, the ARM reference platforms moved away from the footer format parsed by the current AFS code in MTD. As far as I can tell this begun with the RealView reference designs (mach-realview) and the new format has been used in RealView, Versatile Express and recently the Juno Development platform (64bit).

The code has not been working for newer designs for a long time. Proper parsing of the flash image partitions is very helpful when you want to replace firmware when running full Linux and none of the boot monitors or boot loaders.

After this, AFS parsing will work on all ARM reference designs, or well, all I could test. I tested the Integrator/AP, RealView PB11MPCore and Juno Development Platform.

The first 9 patches basically refactors the current code to make the old partition format more encapsulated, while the last patch adds the new v2 format.

Years ago, the ARM reference platforms moved away from the footer format parsed by the current AFS code in MTD. As far as I can tell this begun with the RealView reference designs (mach-realview) and the new format has been used in RealView, Versatile Express and recently the Juno Development platform (64bit).

The code has not been working for newer designs for a long time. Proper parsing of the flash image partitions is very helpful when you want to replace firmware when running full Linux and none of the boot monitors or boot loaders.

After this, AFS parsing will work on all ARM reference designs, or well, all I could test. I tested the Integrator/AP, RealView PB11MPCore and Juno Development Platform.

The first 9 patches basically refactors the current code to make the old partition format more encapsulated, while the last patch adds the new v2 format.

Also, do you have a pointer that documents the v2 format? I can probably find something myself, but I'm a bit lazy, and if you have something easy to point me to, that'd save me some time :)

Quoted 3 lines · Brian Norris

Also, do you have a pointer that documents the v2 format? I can probably find something myself, but I'm a bit lazy, and if you have something easy to point me to, that'd save me some time :)

There are no documents. The documentation is the source code for the on-board boot monitor (first thing started by the ROM) that comes with the board on a CD/DVD. A .h file documents the struct that is simply written to flash as footer and image info. I don't think I may post it, the structs in the kernel correspond to these structs.