How to change endian attribute for a memory region

[Laurent Mohin]

Michaêl,

I can't connect the chip as a byte wide device due to performance
degradation.
Due to other constraints, I can't invert MSB and LSB. In fact, due to color
mapping, if I work in 8 bit per pixel, I must address my framebuffer in big
endian mode. In 16 bit per pixel, I need to use little endian mode.
So I really need to change the endian attribute.

Thanks for your answer

Laurent




"Michael Meriin" <Michael at KSWaves.com> on 14/10/2002 10:57:00

To:    linuxppc-embedded at lists.linuxppc.org, Laurent
       Mohin/SE/Wavetek at Global
cc:
Subject:    Re: How to change endian attribute for a memory region



> I'm trying to interface a 405GP chip with an EPSON S1D13506 graphic
> controller. Because the EPSON chip is a little endian, I need to have my
> framebuffer memory acceded in little endian mode.
> What is the best way to change endian attribute for a specific memory
> region (ioremap little endian)?
>
> Laurent

I suggest you to connect it to the uP as a byte wide device, this will
immediately solve your problem.
The second way you can do it for 16 bit bus to connect MSB and LSB wise a
wiser.
>
Best Regards,
                     Michael Meriin


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