Re: [Linux-fbdev-devel] [PATCH] fix endian problem in color_imageblit

On Thu, 2002-12-12 at 08:41, Paul Mackerras wrote:

This patch fixes the endian problems in color_imageblit().  With this
patch, I get the penguin drawn properly on boot.

The main change is that on big-endian systems, when we load a pixel
from the source, we now shift it to the left-hand (most significant)
end of the word.  With this change the rest of the logic is correct on
big-endian systems.  This may not be the most efficient way to do
things but it is a simple change that works and avoids disturbing the
rest of the code.

Nice catch :-)  We also need a similar fix for slow_imageblit(), so
James can you apply the attached patch also:

Also, I noticed that some drivers load the pseudo_palette with entries 
whose length matches the length of the pixel.  The cfb_* functions 
always assume that each pseudo_palette entry is an "unsigned long", so 
bpp16 will segfault, and so will bpp24/32 for 64-bit machines.

Tony

diff -Naur linux-2.5.51/drivers/video/cfbimgblt.c linux/drivers/video/cfbimgblt.c

--- linux-2.5.51/drivers/video/cfbimgblt.c	2002-12-15 00:54:04.000000000 +0000
+++ linux/drivers/video/cfbimgblt.c	2002-12-15 00:54:21.000000000 +0000

@@ -189,6 +189,7 @@
 				color = fgcolor;
 			else 
 				color = bgcolor;
+			color <<= LEFT_POS(bpp);
 			val |= SHIFT_HIGH(color, shift);
 			
 			/* Did the bitshift spill bits to the next long? */

Tony