Re: How to change endian attribute for a memory region

Michael,

why don't you use the MD4 signal of the Epson Chip to configure it as big
endian device? Or am I missing something here?

Best regards,
Stefan.

-----Ursprüngliche Nachricht-----
Von: owner-linuxppc-embedded@lists.linuxppc.org
[mailto:owner-linuxppc-embedded@lists.linuxppc.org]Im Auftrag von
Laurent Mohin
Gesendet: Dienstag, 15. Oktober 2002 11:08
An: Michael Meriin
Cc: linuxppc-embedded@lists.linuxppc.org
Betreff: Re: How to change endian attribute for a memory region



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" [off-list ref] on 14/10/2002 10:57:00

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

quoted

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.

quoted

Best Regards,
                     Michael Meriin

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