From: Eric Nelson <eric.nelson@boundarydevices.com>
Date: Sat, 8 Mar 2014 14:55:52 +0000 (-0700)
Subject: cfb_console: align fields in gzipped .bmp files
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=5ca05c8b0304c6e99466fd3c43398273c1e9cad9;p=u-boot.git

cfb_console: align fields in gzipped .bmp files

.bmp files contain 32-bit integers aligned at offsets of +2, +6,
et cetera within the bmp_header structure (see include/bmp_layout.h).

Support for gzip-compressed .bmp files is present in the cfb_console
display subsystem by uncompressing them prior to use.

This patch forces the in-memory header to be aligned properly
for these compressed images by extracting them to a 2-byte
offset in the memory returned by malloc. Since malloc will always
return a 4-byte aligned value, this forces the .bmp header
fields to be naturally aligned on 4-byte addresses.

Refer to these files for more details:
	doc/README.displaying-bmps

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
---

diff --git a/drivers/video/cfb_console.c b/drivers/video/cfb_console.c
index 6db4073596..b52e9edd25 100644
--- a/drivers/video/cfb_console.c
+++ b/drivers/video/cfb_console.c
@@ -1473,7 +1473,11 @@ int video_display_bitmap(ulong bmp_image, int x, int y)
 			printf("Error: malloc in gunzip failed!\n");
 			return 1;
 		}
-		if (gunzip(dst, CONFIG_SYS_VIDEO_LOGO_MAX_SIZE,
+		/*
+		 * NB: we need to force offset of +2
+		 * See doc/README.displaying-bmps
+		 */
+		if (gunzip(dst+2, CONFIG_SYS_VIDEO_LOGO_MAX_SIZE-2,
 			   (uchar *) bmp_image,
 			   &len) != 0) {
 			printf("Error: no valid bmp or bmp.gz image at %lx\n",
@@ -1489,7 +1493,7 @@ int video_display_bitmap(ulong bmp_image, int x, int y)
 		/*
 		 * Set addr to decompressed image
 		 */
-		bmp = (bmp_image_t *) dst;
+		bmp = (bmp_image_t *)(dst+2);
 
 		if (!((bmp->header.signature[0] == 'B') &&
 		      (bmp->header.signature[1] == 'M'))) {