Hi,
Please let me know if Little endianness is supported in OR1200. We want to port some x86 code on this processor, and that code will be in Little endian.
What changes would be needed in the design to support this???

Thanks,
Rajani

Hi Rajani

OpenRISC can be little endian or big endian, but to date there have only been big-endian implementations and only the big-endian tool chain is properly tested and supported.

However, surely your code is not endian dependent? The obvious solution is to fix the code, not the processor!

Best wishes,

Jeremy

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Thanks Jeremy for the quick reply.
As I mentioned, we need to port an existing standard windows based code onto this processor, hence the code cannot be altered.
I did see that the SPR register has a bit indicating the support for Little endian. But nowhere in the RTL the implementation exists.
Please let us know if any latest version has this support.

Thanks

This is my patch for the little-endian support on RTL code.

http://opencores.org/forum,OpenRISC,0,4093

But there's no toolchains to support it yet.

Thank You.

Hi Kuoping,

Please let me know if the patch expects the testcode to be in Little Endian format. I have added your patch to my latest RTL and I have a testcase that is apparently in little endian format, but the CPU is not able to understand the code. I think the patch doesn't include logic to pick up the instructions in a different order if the code is also little endian.
Please let me know.

Thanks,
Rajani

changing the title.