Big-Endian problem with Fujitsu CoralPA
clemens.koller at anagramm.de
Thu Nov 8 08:58:52 PST 2007
Eduard Fuchs schrieb:
> A few words about my system: This is a custom-designed board, based on a
> PowerPC CPU (MPC7448) and Marvell MV64560 chip-set. On the PCI bus are
> connnected graphic chip Fujitsu CoralPA(MB86296) and sATA Controller.
> The OS is Linux with kernel ver. 2.6.12.
> Now the problem – it is an Endian problem. The graphic chip supprts only
> up to 16-Bits color mode and Little Endian bits arrangement. This causes
> a wrong color picture on the screen. There is no possibility (anyway, I
> was not found) to correct the bits seqence direct in the graphics
> controller. I can activate bits-swapping on PCI controller (Marvell
> chip-set supports 32, resp. 64 bit-swapping). Then the colors are OK,
> but now I have errors in the picture representation.
Oh, sh***... you seem to have the same problem as we had with
the Silicon Motion SM501 graphics chip on PowerPC's PCI (which is
quite solved now...)
> Is this a possibility to adapt the X-server resp. Xlib so, that the
> pixel-data is from the CPU corrected? As a graphics driver I use
> framebufer device driver from the Linux kernel.
I don't know the CoralPA driver infrastructure of the kernel.
The xorg driver, however, could be fixed in the driver source.
There is no need to modify the Xlib etc, AFAICT.
The SM501 the xorg driver was modified for PPC architecture and is
working now (for me). Just for your reference, see the last commits
of the xf86-video-smi501 git tree at:
R&D Imaging Devices
More information about the xorg