[ECOS] Generic framebuffer support

Bart Veer bartv@ecoscentric.com
Sun Nov 9 16:08:00 GMT 2008

>>>>> "tgabor84" == =?ISO-8859-1?Q?G=E1bor T=F6r=F6k?= <tgabor84@gmail.com> writes:

    tgabor84> Hi!
    tgabor84> I think I have found a bug in the generic framebuffer
    tgabor84> code in function "cyg_fb_linear_move_block_16_impl" in
    tgabor84> "linear.c". I think the code below should either init
    tgabor84> source and dest with (height-1) or do the decrements
    tgabor84> before the memcpy in the for loop.

    tgabor84>     // There is an overlap. Can we do a safe bottom-to-top lot of memcpy()'s ?
    tgabor84>     if (new_y > y) {
    tgabor84>         source = (cyg_uint16*)(((cyg_uint8*)source) + (height * stride8));
    tgabor84>         dest   = (cyg_uint16*)(((cyg_uint8*)dest)   + (height * stride8));
    tgabor84>         width <<= 1;
    tgabor84>         for ( ; height; height--) {
    tgabor84>             __builtin_memcpy(dest, source, width);
    tgabor84>             source   = (cyg_uint16*)(((cyg_uint8*)source) - stride8);
    tgabor84>             dest     = (cyg_uint16*)(((cyg_uint8*)dest) - stride8);
    tgabor84>         }
    tgabor84>         return;
    tgabor84>     }

Agreed. I have checked in a fix which does the decrement before the

Bart Veer                                   eCos Configuration Architect
eCosCentric Limited    The eCos experts      http://www.ecoscentric.com/
Barnwell House, Barnwell Drive, Cambridge, UK.      Tel: +44 1223 245571
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