[U-Boot] [PATCH V2] cfb_console: force natural alignment of 32-bit 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 doc/README.arm-unaligned-accesses
Signed-off-by: Eric Nelson eric.nelson@boundarydevices.com --- drivers/video/cfb_console.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/video/cfb_console.c b/drivers/video/cfb_console.c index 6db4073..2209148 100644 --- a/drivers/video/cfb_console.c +++ b/drivers/video/cfb_console.c @@ -1473,7 +1473,10 @@ 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 +1492,7 @@ 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'))) {
Dear Eric Nelson,
your message contains no thread information - there is neither a In-reply-to: nor any References: header. This is bad!
Please also make sure to keep the Subject: test short; the recommended style for the commit message is "50/72 formatting", i. e. the Subject should not exceed 50 (...60) characters.
In message 1393621572-10306-1-git-send-email-eric.nelson@boundarydevices.com you wrote:
.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 doc/README.arm-unaligned-accesses
Signed-off-by: Eric Nelson eric.nelson@boundarydevices.com
drivers/video/cfb_console.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
So what exactly has changed since version 1? Please note that the change log is mandatory!
diff --git a/drivers/video/cfb_console.c b/drivers/video/cfb_console.c index 6db4073..2209148 100644 --- a/drivers/video/cfb_console.c +++ b/drivers/video/cfb_console.c @@ -1473,7 +1473,10 @@ 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*/
Incorrect multiline comment style, please fix.
I asked you before to fix that, please make sure not to ignore review comments!
Best regards,
Wolfgang Denk
Sorry Wolfgang,
On 02/28/2014 02:44 PM, Wolfgang Denk wrote:
Dear Eric Nelson,
your message contains no thread information - there is neither a In-reply-to: nor any References: header. This is bad!
Please also make sure to keep the Subject: test short; the recommended style for the commit message is "50/72 formatting", i. e. the Subject should not exceed 50 (...60) characters.
Okay. I was trying to be more explicit here.
In message 1393621572-10306-1-git-send-email-eric.nelson@boundarydevices.com you wrote:
.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 doc/README.arm-unaligned-accesses
Signed-off-by: Eric Nelson eric.nelson@boundarydevices.com
drivers/video/cfb_console.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
So what exactly has changed since version 1? Please note that the change log is mandatory!
Got it.
diff --git a/drivers/video/cfb_console.c b/drivers/video/cfb_console.c index 6db4073..2209148 100644 --- a/drivers/video/cfb_console.c +++ b/drivers/video/cfb_console.c @@ -1473,7 +1473,10 @@ 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*/Incorrect multiline comment style, please fix.
I asked you before to fix that, please make sure not to ignore review comments!
Not intentional... Will fix in V3.
Regards,
Eric
participants (2)
-
Eric Nelson -
Wolfgang Denk