On 1/23/26 11:40 AM, Anshul Dalal wrote:
Hi Marek,

On Fri Jan 23, 2026 at 3:57 PM IST, Marek Vasut wrote:
On 1/23/26 4:32 AM, Beleswar Prasad Padhi wrote:

On 23/01/26 00:33, Marek Vasut wrote:
On 1/22/26 6:45 PM, Tom Rini wrote:
On Thu, Jan 22, 2026 at 10:52:47PM +0530, Beleswar Padhi wrote:

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")

The mkimage tool already supports enforcing this alignment via the -B
option, but users would have to specify it explicitly. This change
makes 8-byte alignment the default when using -b.

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: Beleswar Padhi <[email protected]>

Tested-by: Tom Rini <[email protected]>
Doesn't this enable 8-byte alignment for everything in case a DT is specified 
on mkimage command line ? That doesn't seem right ?

If I do mkimage -f auto -b ...dtb ... , then I only want the DTB to be 8-byte 
aligned, all the other blobs can be 4 byte aligned just fine .


All the mkimage flags are parsed at once and populated in the params
data structure in one shot in the code. There is no separation of code
specifically for generating a FIT for a DTB vs for anything else.

That does not seem to be true ?

$ git grep -p '\<bl_len\>' tools/
tools/fit_image.c=static int fit_extract_data(struct image_tool_params
*params, const char *fname)
tools/fit_image.c:      align_size = params->bl_len ? params->bl_len : 4;
...

So something like that may work ?

"
diff --git a/tools/fit_image.c b/tools/fit_image.c
index 0306333141e..0c606ba4cc3 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -642,9 +642,15 @@ 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;

+               if (align_size < 8) {
+                       type = fdt_getprop(fdt, node, FIT_TYPE_PROP, &len);
+                       if (type && !strcmp(type, "flat_dt"))
+                               align_size = 8;
+               }
+
                  data = fdt_getprop(fdt, node, FIT_DATA_PROP, &len);
                  if (!data)
                          continue;
"


I just ran a quick test with this diff and it seems to fix the issue for
us. If it's okay can we take the change as is.
I think the strcmp needs to be some strncmp and check the 'len' too.

Let's see what others think.

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