[PATCH] image: Set load_end on partial loads

[Mattijs Korpershoek]

When decompressing, it's possible that the algorithm only performs
a partial decompression.
This usually happens when CONFIG_SYS_BOOTM_LEN is too small for
the uncompressed image.

When that happens, image_decomp() returns an error and *load_end == load.
The error is then handled by handle_decomp_error().

handle_decomp_error() expects the number of uncompressed bytes in
uncomp_size but receives *load_end - load == load - load == 0.

Because of this, handle_decomp_error does not report the expected
"Image too large: increase CONFIG_SYS_BOOTM_LEN" error message.

Modify the image_decomp() logic to always report the decompressed size,
even when a partial decompression happened.

Signed-off-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
---
This has been tested on an AM62X SK EVM board with a big lz4 image and
the default CONFIG_SYS_BOOTM_LEN of 0x800000.

This has also been tested on sandbox using:
=> ut compression
---
 boot/image.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/boot/image.c b/boot/image.c
index 073931cd7a3f..4f48e6eb563d 100644
--- a/boot/image.c
+++ b/boot/image.c
@@ -531,10 +531,10 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 		printf("Unimplemented compression type %d\n", comp);
 		return ret;
 	}
-	if (ret)
-		return ret;
 
 	*load_end = load + image_len;
+	if (ret)
+		return ret;
 
 	return 0;
 }

---
base-commit: a7f0154c412859323396111dd0c09dbafbc153cb
change-id: 20240523-image-partial-decomp-d6604e998e3a

Best regards,
-- 
Mattijs Korpershoek <mkorpershoek at baylibre.com>