Re: 8e35bb07eb mkimage: Support automatic creating of a FIT without a .its
Hi Wolfgang,
On Mon, 25 May 2020 at 05:38, Wolfgang Denk wrote:
>
> Hi Simon,
>
> your commit 8e35bb07eb (2016-03-14) "mkimage: Support automatic
> creating of a FIT without a .its" added the "-f auto" option to
> mkimage. While convenient in many situation, I had to notice that
> with "-f auto" there is no checksum information included with any of
> the blobs stored in the FIT image.
>
> I guess the rationale was that the primary use case for this was to
> generate combinations of a U-Boot image with several device tree
> blobs to be used / selected by the SPL, as one can see for example
> in scripts/Makefile.spl :
>
> MKIMAGEFLAGS_$(SPL_BIN).multidtb.fit = -f auto -A $(ARCH) -T firmware -C none
> -O u-boot \
> -n "Multi DTB fit image for $(SPL_BIN)" -E \
> $(patsubst %,-b %,$(SHRUNK_ARCH_DTB))
>
> And - at least at that time - most implementations of the SPL did
> not need/want checksum verification.
>
>
> However I'm asking myself if this is not an unfortunate choice.
> It is trivial for a not-checksum-enabled SPL to ignore any checksum
> in the image, but not the other way round: if there is no checksum
> in the images, the SPL will never be able to verify one.
>
>
> Would it not be a more reasonable default for operation unter the
> "-f auto" flag to enable at least simple checksumming, say by
> auto-adding something like
>
> hash-1 {
> algo = "crc32";
> };
>
> to the generated descriptions?
Yes it should be easy to add that. I'll take a look.
Regards,
Simon
8e35bb07eb mkimage: Support automatic creating of a FIT without a .its
Hi Simon,
your commit 8e35bb07eb (2016-03-14) "mkimage: Support automatic
creating of a FIT without a .its" added the "-f auto" option to
mkimage. While convenient in many situation, I had to notice that
with "-f auto" there is no checksum information included with any of
the blobs stored in the FIT image.
I guess the rationale was that the primary use case for this was to
generate combinations of a U-Boot image with several device tree
blobs to be used / selected by the SPL, as one can see for example
in scripts/Makefile.spl :
MKIMAGEFLAGS_$(SPL_BIN).multidtb.fit = -f auto -A $(ARCH) -T firmware -C none
-O u-boot \
-n "Multi DTB fit image for $(SPL_BIN)" -E \
$(patsubst %,-b %,$(SHRUNK_ARCH_DTB))
And - at least at that time - most implementations of the SPL did
not need/want checksum verification.
However I'm asking myself if this is not an unfortunate choice.
It is trivial for a not-checksum-enabled SPL to ignore any checksum
in the image, but not the other way round: if there is no checksum
in the images, the SPL will never be able to verify one.
Would it not be a more reasonable default for operation unter the
"-f auto" flag to enable at least simple checksumming, say by
auto-adding something like
hash-1 {
algo = "crc32";
};
to the generated descriptions?
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
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Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
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but the result's the same." - Mike Dennison
