Re: [ptxdist] [PATCH v2] ptxd_make_fit_image: pad FIT image to block size of 4096 bytes

[Roland Hieber <rhi@pengutronix.de>]

On Wed, Aug 23, 2023 at 12:49:59PM +0200, Roland Hieber wrote:
> Trying to flash a FIT image over fastboot often results in errors like
> this:
> 
>     Invalid sparse file format at header magic
>     error: write_sparse_skip_chunk: don't care size 18394488 is not a multiple of the block size 4096
>     error: write_sparse_skip_chunk: don't care size 10009976 is not a multiple of the block size 4096
>     error: write_sparse_skip_chunk: don't care size 1625464 is not a multiple of the block size 4096
>     [...]
>     FAILED (remote: 'writing sparse image: Invalid argument')
> 
> The FIT image knows about its own size anyway, so to get around this
> issue, we can simply pad the image to a multiple of 4 kiB to make it
> work with the fastboot sparse magic.
> 
> Suggested-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

For reference, Ahmad also posted a more detailed explanation and a patch
addressing the situation on the barebox list:
<https://lore.barebox.org/barebox/20230825172250.2857448-1-a.fatoum@pengutronix.de/>

(However the problem still persists on other bootloaders.)

 - Roland

> Signed-off-by: Roland Hieber <rhi@pengutronix.de>
> ---
> v2: clean up the temp image too
> ---
>  scripts/lib/ptxd_make_fit_image.sh | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/scripts/lib/ptxd_make_fit_image.sh b/scripts/lib/ptxd_make_fit_image.sh
> index dd0f63b7b72d..8162195fdfa3 100644
> --- a/scripts/lib/ptxd_make_fit_image.sh
> +++ b/scripts/lib/ptxd_make_fit_image.sh
> @@ -139,6 +139,8 @@ ptxd_make_image_fit() {
>  	echo "Generated device-tree for the fit image:"
>  	cat "${its}"
>      fi &&
> -    ptxd_exec mkimage -N pkcs11 -f "${its}" "${image_image}" -r "${sign_args[@]}"
> +    ptxd_exec mkimage -N pkcs11 -f "${its}" "${image_image}.tmp" -r "${sign_args[@]}" &&
> +    ptxd_exec dd if="${image_image}.tmp" of="${image_image}" conv=sync bs=4k &&
> +    ptxd_exec rm "${image_image}.tmp"
>  }
>  export -f ptxd_make_image_fit
> -- 
> 2.39.2
> 
> 
> 

-- 
Roland Hieber, Pengutronix e.K.          | r.hieber@pengutronix.de     |
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