Porting a driver from x86 to LinucPPC

Porting a driver from x86 to LinucPPC

[Bryan Christianson]

I'm trying to port a device driver from x86 to linuxppc. I am running into
problems with big/little endian-ness.

The device is a PCI card. Do I need to explicitly translate the data
between big-endian and little-endian or will the io routines (outl, inl and
inw) take care of this for me? On x86 I didn't even think about this issue,
but now I have a feeling that maybe I should have.

--
Bryan Christianson
email:		<mailto:bryanc@ihug.co.nz>
Home Page:	<http://crash.ihug.co.nz/~bryanc>



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Re: Porting a driver from x86 to LinucPPC

[Jens Ch. Restemeier]

Bryan Christianson wrote:
> 
> I'm trying to port a device driver from x86 to linuxppc. I am running into
> problems with big/little endian-ness.
> 
> The device is a PCI card. Do I need to explicitly translate the data
> between big-endian and little-endian or will the io routines (outl, inl and
> inw) take care of this for me? On x86 I didn't even think about this issue,
> but now I have a feeling that maybe I should have.

I just fixed the NE2000 driver for this.

inl/outl will fix PCI's liddle-endianess to host-endianness. There is
some documentation in include/asm/io.h.

Jens


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Re: Porting a driver from x86 to LinucPPC

[Bryan Christianson]

>Bryan Christianson wrote:
>>
>> I'm trying to port a device driver from x86 to linuxppc. I am running into
>> problems with big/little endian-ness.
>>
>> The device is a PCI card. Do I need to explicitly translate the data
>> between big-endian and little-endian or will the io routines (outl, inl and
>> inw) take care of this for me? On x86 I didn't even think about this issue,
>> but now I have a feeling that maybe I should have.
>
>I just fixed the NE2000 driver for this.
>
>inl/outl will fix PCI's liddle-endianess to host-endianness. There is
>some documentation in include/asm/io.h.
>

Thanks - I've got the thing working now. The inl/outl stuff worked fine,
but this card also uses inw. I had to flip the bytes on the returned value
and the card burst into life.

Bryan

--
Bryan Christianson
email:		<mailto:bryanc@ihug.co.nz>
Home Page:	<http://crash.ihug.co.nz/~bryanc>



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