Re: [PATCH] Add cross compile to top level configuration file

[Anthony Liguori <anthony-rdkfGonbjUSkNkDKm+mE6A@public.gmane.org>]

Jerone Young wrote:
> On Tue, 2007-10-16 at 09:59 -0500, Anthony Liguori wrote:
>   
>> Jerone Young wrote:
>>     
>>> On Mon, 2007-10-15 at 15:13 -0500, Anthony Liguori wrote:
>>>   
>>>
>>>       
>>>>> +fi
>>>>> +
>>>>> +qemudir=`pwd`/qemu
>>>>> +
>>>>> +#configure user dir
>>>>> +(cd user; ./configure --prefix="$prefix" --kerneldir="$libkvm_kerneldir" \
>>>>> +          $user_opts --arch="$arch")
>>>>> +(cd qemu; ./configure --target-list=$target_exec \
>>>>>      --disable-kqemu --extra-cflags="-I $PWD/../user" \
>>>>>      --extra-ldflags="-L $PWD/../user" \
>>>>>      --enable-kvm --kernel-path="$libkvm_kerneldir" \
>>>>> -    --enable-alsa \
>>>>>      ${disable_gcc_check:+"--disable-gcc-check"} \
>>>>> -    --prefix="$prefix"
>>>>> +    --prefix="$prefix" \
>>>>> +    $qemu_opts --cpu="$arch"
>>>>>   
>>>>>       
>>>>>           
>>>> I don't think this is right.  You're using two different --cpu options 
>>>> for i386 and x86_64.  There really shouldn't be a --cpu option at all 
>>>> for x86.
>>>>     
>>>>         
>>> So the --cpu option is actually a hidden option in qemu & is not on the
>>> qemu help page .. who know why it isn't but the it's in the code.
>>>
>>> It makes since though that if you are going to specify cross-prefix=
>>> then there is little reason to specify the cpu on the qemu line. As it
>>> should detect everything from cross compiler.
>>>
>>> I'll test this out and send a new patch with the 2 changes.
>>>   
>>>       
>> So, instead of doing the funky $qemu_opts thing, why not just do:
>>
>>    
>> ${cross_prefix:+"--cross-prefix=${cross_prefix} --cpu=${arch}"}
>
> Well you could but what I need to is satisfy the situation that if you
> have --qemu-cc specified that it not use it. I'm not sure how you do
> this in one line in bash. So I have 
>
> if [[ -z $cross_prefix ]]; then
> 	  qemu_opts+=" --cc=$cc"
> else
> 	  qemu_opts+=" --cross-prefix=$cross_prefix"
> fi 
>   

Unconditionally passing --cc to qemu seems like a bad idea to me.  I 
think what you really want is:

	${cross_prefix:+"--cross-prefix=${cross_prefix} --cpu=${arch}"} \
	${qemu_cc:+"--cc=${qemu_cc}"}


QEMU doesn't perform the same checks if you explicitly pass --cc so if 
you do this unconditionally, it will do ugly things like try to use gcc4 
instead of finding gcc3.2

Regards,

Anthony Liguori

> Also after this options are added to $qemu_opts based on what
> architecture you are compiling for. For now you only see x86-64 & i386.
> But this is about to change .. if I can ever get this patch in :-)
>
> Also it becomes even more complicated with the next version of the patch
> I'll be sending out in out.
>
>
>
>   
>> Regards,
>>
>> Anthony Liguori
>>
>>
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>
>
>   


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