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

[Roland Hieber <rhi@pengutronix.de>]

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>
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