On 1/28/26 5:48 PM, Sean Anderson wrote:
Hi Beleswar,
On 1/28/26 09:18, Beleswar Padhi wrote:
From: Marek Vasut <[email protected]>
When CONFIG_SPL_MULTI_DTB_FIT is enabled, multiple device trees are
packed inside the multidtb.fit FIT image. While the individual DTBs
and the FIT image start address are 8-byte aligned, the DTBs embedded
within the FIT image are not guaranteed to maintain 8-byte alignment.
This misalignment causes -FDT_ERR_ALIGNMENT failure in
setup_multi_dtb_fit() when locating the next available DTB within the
FIT blob and setting gd->fdt_blob, because of the recent libfdt
hardening since commit 0535e46d55d7 ("scripts/dtc: Update to upstream
version v1.7.2-35-g52f07dcca47c")
To fix this, check the image type when extracting FIT image data and
set the alignment size to 8 bytes (if not already) only for flat_dt
images. This ensures correct alignment for device tree blobs as per the
DT spec, while also allowing different alignment sizes for other image
types within the FIT.
Reported-by: Anshul Dalal <[email protected]>
Closes: https://lore.kernel.org/u-boot/[email protected]
Fixes: 0535e46d55d7 ("scripts/dtc: Update to upstream version
v1.7.2-35-g52f07dcca47c")
Signed-off-by: Marek Vasut <[email protected]>
Signed-off-by: Beleswar Padhi <[email protected]>
---
Testing Done:
1. Boot tested on all TI K3 platforms.
v4: Changelog:
1. Align only the DTBs to 8-bytes, other images in a FIT can have their
independent alignment. [Marek]
Link to v3:
https://lore.kernel.org/all/[email protected]/
v3: Changelog:
1. Default to 8-byte alignment for DTBs in mkimage instead of
passing -B 0x8 in build command [Marek]
2. Remove previous R/Bs.
Link to v2:
https://lore.kernel.org/all/[email protected]/
v2: Changelog:
1. Carry R/B, Reported-by, Closes and Fixes tag.
Link to v1:
https://lore.kernel.org/all/[email protected]/
tools/fit_image.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
Can you please update doc/mkimage.1 as well? There should be a note about
this under -E.
diff --git a/tools/fit_image.c b/tools/fit_image.c
index e865f65a400..f842c845771 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -682,9 +682,17 @@ static int fit_extract_data(struct
image_tool_params *params, const char *fname)
for (node = fdt_first_subnode(fdt, images);
node >= 0;
node = fdt_next_subnode(fdt, node)) {
- const char *data;
+ const char *data, *type;
int len;
+ /* Fallback to 8-byte alignment for DTBs if unaligned */
+ type = fdt_getprop(fdt, node, FIT_TYPE_PROP, &len);
+ if (type &&
+ len == sizeof("flat_dt") &&
+ !memcmp(type, "flat_dt", len) &&
+ align_size & 0x7)
+ align_size = 8;
+
Doesn't this increase the alignment for all images following the
devicetree?
And actually, doesn't this happen too late? By the time we check whether
the
node is a devicetree, buf_ptr has already been updated. This check will
only
affect the alignment of the *next* image in the FIT.
How about we turn this around this way, add up the alignments first to
deal with allocation, and then fiddle with the buf_ptr based on the
previous iteration to layout the images ?
diff --git a/tools/fit_image.c b/tools/fit_image.c
index e865f65a400..82ffd03c288 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -651,10 +651,9 @@ static int fit_extract_data(struct
image_tool_params *params, const char *fname)
int ret;
int images;
int node;
- int image_number;
- int align_size;
+ int align_size = 0;
+ int len = 0;
- align_size = params->bl_len ? params->bl_len : 4;
fd = mmap_fdt(params->cmdname, fname, 0, &fdt, &sbuf, false, false);
if (fd < 0)
return -EIO;
@@ -666,24 +665,54 @@ static int fit_extract_data(struct
image_tool_params *params, const char *fname)
ret = -EINVAL;
goto err_munmap;
}
- image_number = fdtdec_get_child_count(fdt, images);
+
+ /* Add up all the alignments, we no longer need to count images. */
+ fdt_for_each_subnode(node, fdt, images) {
+ const char *type;
+ int len;
+
+ if (params->bl_len) {
+ align_size += params->bl_len;
+ continue;
+ }
+
+ type = fdt_getprop(fdt, node, FIT_TYPE_PROP, &len);
+ if (type && len == sizeof("flat_dt") && !memcmp(type,
"flat_dt", len)) {
+ align_size += 8; // or params->bl_len rounded up to 8 ?
+ continue;
+ }
+
+ /* Default alignment to 4 Bytes */
+ align_size += 4;
+ }
/*
* Allocate space to hold the image data we will extract,
* extral space allocate for image alignment to prevent overflow.
*/
- buf = calloc(1, fit_size + (align_size * image_number));
+ buf = calloc(1, fit_size + align_size);
if (!buf) {
ret = -ENOMEM;
goto err_munmap;
}
buf_ptr = 0;
- for (node = fdt_first_subnode(fdt, images);
- node >= 0;
- node = fdt_next_subnode(fdt, node)) {
- const char *data;
- int len;
+ fdt_for_each_subnode(node, fdt, images) {
+ const char *data, *type;
+ int pl;
+
+ if (params->bl_len)
+ align_size = 8;//params->bl_len;
+ else {
+ type = fdt_getprop(fdt, node, FIT_TYPE_PROP, &pl);
+ if (type && pl == sizeof("flat_dt") && !memcmp(type,
"flat_dt", pl))
+ align_size = 8; // or params->bl_len rounded up
to 8 ?
+ else /* Default alignment to 4 Bytes */
+ align_size = 8;
+ }
+
+ /* len is 0 in first round, else comes from previous round. */
+ buf_ptr += ALIGN(len, align_size);
data = fdt_getprop(fdt, node, FIT_DATA_PROP, &len);
if (!data)
@@ -716,10 +745,11 @@ static int fit_extract_data(struct
image_tool_params *params, const char *fname)
ret = -EINVAL;
goto err_munmap;
}
-
- buf_ptr += ALIGN(len, align_size);
}
+ /* comes from previous round. */
+ buf_ptr += ALIGN(len, align_size);
+
/* Pack the FDT and place the data after it */
fdt_pack(fdt);
--From 7149d1052332b55242e5428ab762b6e20a60779e Mon Sep 17 00:00:00 2001
From: Marek Vasut <[email protected]>
Date: Wed, 28 Jan 2026 19:48:34 +0530
Subject: [PATCH] tools: fit_image: Fallback to 8-byte alignment for flat_dt
images
When CONFIG_SPL_MULTI_DTB_FIT is enabled, multiple device trees are
packed inside the multidtb.fit FIT image. While the individual DTBs
and the FIT image start address are 8-byte aligned, the DTBs embedded
within the FIT image are not guaranteed to maintain 8-byte alignment.
This misalignment causes -FDT_ERR_ALIGNMENT failure in
setup_multi_dtb_fit() when locating the next available DTB within the
FIT blob and setting gd->fdt_blob, because of the recent libfdt
hardening since commit 0535e46d55d7 ("scripts/dtc: Update to upstream
version v1.7.2-35-g52f07dcca47c")
To fix this, check the image type when extracting FIT image data and
set the alignment size to 8 bytes (if not already) only for flat_dt
images. This ensures correct alignment for device tree blobs as per the
DT spec, while also allowing different alignment sizes for other image
types within the FIT.
Reported-by: Anshul Dalal <[email protected]>
Closes: https://lore.kernel.org/u-boot/[email protected]
Fixes: 0535e46d55d7 ("scripts/dtc: Update to upstream version v1.7.2-35-g52f07dcca47c")
Signed-off-by: Marek Vasut <[email protected]>
Signed-off-by: Beleswar Padhi <[email protected]>
---
tools/fit_image.c | 54 ++++++++++++++++++++++++++++++++++++-----------
1 file changed, 42 insertions(+), 12 deletions(-)
diff --git a/tools/fit_image.c b/tools/fit_image.c
index e865f65a400..82ffd03c288 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -651,10 +651,9 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname)
int ret;
int images;
int node;
- int image_number;
- int align_size;
+ int align_size = 0;
+ int len = 0;
- align_size = params->bl_len ? params->bl_len : 4;
fd = mmap_fdt(params->cmdname, fname, 0, &fdt, &sbuf, false, false);
if (fd < 0)
return -EIO;
@@ -666,24 +665,54 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname)
ret = -EINVAL;
goto err_munmap;
}
- image_number = fdtdec_get_child_count(fdt, images);
+
+ /* Add up all the alignments, we no longer need to count images. */
+ fdt_for_each_subnode(node, fdt, images) {
+ const char *type;
+ int len;
+
+ if (params->bl_len) {
+ align_size += params->bl_len;
+ continue;
+ }
+
+ type = fdt_getprop(fdt, node, FIT_TYPE_PROP, &len);
+ if (type && len == sizeof("flat_dt") && !memcmp(type, "flat_dt", len)) {
+ align_size += 8; // or params->bl_len rounded up to 8 ?
+ continue;
+ }
+
+ /* Default alignment to 4 Bytes */
+ align_size += 4;
+ }
/*
* Allocate space to hold the image data we will extract,
* extral space allocate for image alignment to prevent overflow.
*/
- buf = calloc(1, fit_size + (align_size * image_number));
+ buf = calloc(1, fit_size + align_size);
if (!buf) {
ret = -ENOMEM;
goto err_munmap;
}
buf_ptr = 0;
- for (node = fdt_first_subnode(fdt, images);
- node >= 0;
- node = fdt_next_subnode(fdt, node)) {
- const char *data;
- int len;
+ fdt_for_each_subnode(node, fdt, images) {
+ const char *data, *type;
+ int pl;
+
+ if (params->bl_len)
+ align_size = 8;//params->bl_len;
+ else {
+ type = fdt_getprop(fdt, node, FIT_TYPE_PROP, &pl);
+ if (type && pl == sizeof("flat_dt") && !memcmp(type, "flat_dt", pl))
+ align_size = 8; // or params->bl_len rounded up to 8 ?
+ else /* Default alignment to 4 Bytes */
+ align_size = 8;
+ }
+
+ /* len is 0 in first round, else comes from previous round. */
+ buf_ptr += ALIGN(len, align_size);
data = fdt_getprop(fdt, node, FIT_DATA_PROP, &len);
if (!data)
@@ -716,10 +745,11 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname)
ret = -EINVAL;
goto err_munmap;
}
-
- buf_ptr += ALIGN(len, align_size);
}
+ /* comes from previous round. */
+ buf_ptr += ALIGN(len, align_size);
+
/* Pack the FDT and place the data after it */
fdt_pack(fdt);
--
2.51.0
