Endian issue
From: Laurent Lagrange <hidden>
Date: 2006-11-27 14:55:02
Hi I'm writing a framebuffer driver and I have some endian problems. My board is big endian (powerpc inside) and I use a little endian graphic card. I try to get a 16 bpp RGBA (5/5/5/1) true color mode working. Nevertheless, I have troubles with the framebuffer layer. For example, in the color_imageblit function of cfbimgblt.c, if I want to draw two 16bpp rgba pixels P0 (0xFFFE) and P1 (0x0001), they are packed together like this 0xFFFE_0001. In memory, 0xFF is LSB, 0x01 is MSB (big endian). Then this 32bit value is "__raw_writel" to the memory of the video card. As my videocard works in little endian, I get 0x0100_FEFF. So the pixels are at the correct place, but don't have the correct color. It would be OK if it was 0x0001_FFFE. My question is : - is it possible to use generic drawing function (blit, fillrect...) on a big endian board with a little endian graphics card ? - if yes, how can I describe the colors bitfields, without patching the kernel code, to get the correct color ? Thanks Laurent ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV