Re: [Qemu-devel] [RFC PATCH] Allow building without graphics support

[Scott Wood <scottwood@freescale.com>]

On 12/12/2012 12:46:44 AM, Stefan Weil wrote:
> Am 12.12.2012 04:18, schrieb Scott Wood:
>> QEMU is sometimes used in embedded contexts, where graphical support
>> is unnecessary.  The ability to turn off graphics support not only
>> saves some space, but it eliminates the dependency on pixman.
>> 
>> Signed-off-by: Scott Wood <scottwood@freescale.com>
>> ---
>> There are undoubtedly some rough edges that need to be cleaned up and
>> other parts of graphics code that could be compiled out -- this is  
>> mainly
>> meant to see what people think of the concept.
>> 
>> My immediate motivation was that the QEMU-supplied pixman was being a
>> pain to cross compile (especially without hacking up the generated  
>> QEMU
>> makefiles to pass additional things to pixman's configure), and in
>> general it would be nice to not have to carry around graphical  
>> baggage
>> when running on hardware that doesn't even have a display (so I was  
>> more
>> inclined to do this than to spend effort fixing the pixman build).
> 
> Hi,
> 
> cross compilation works for me with the internal pixman.
> Here is an example which I use to compile Windows 64 bit
> executables on Debian:
> 
> ./configure' '--cross-prefix=amd64-mingw32msvc-'
> 
> Are there still problems with cross compilation in latest QEMU?

It doesn't seem to like my --cross-prefix being a full path rather than  
being a recognized target pattern:

checking host system type... Invalid configuration  
`/home/scott/fsl/tc/gcc-4.5.55-eglibc-2.11.55/powerpc-linux-gnu/bin/powerpc-linux-gnu':  
machine  
`/home/scott/fsl/tc/gcc-4.5.55-eglibc-2.11.55/powerpc-linux-gnu/bin/powerpc'  
not recognized
configure: error: /bin/bash /home/scott/fsl/git/qemu/pixman/config.sub  
/home/scott/fsl/tc/gcc-4.5.55-eglibc-2.11.55/powerpc-linux-gnu/bin/powerpc-linux-gnu  
failed
make: *** [pixman/Makefile] Error 1

When I forced --host=powerpc-linux into the pixman configure command in  
QEMU's generated Makefile, it got past that, but it built everything  
with the native compiler:

checking build system type... x86_64-unknown-linux-gnu
checking host system type... powerpc-unknown-linux-gnu
checking for powerpc-linux-gcc... no
checking for gcc... gcc

Looking a bit more closely, it seems that it's the QEMU rather than  
pixman's autoconf that is making the bad assumption about the format of  
--cross-prefix (I really wasn't up for wading in autoconf).  Running  
basename on cross-prefix and explicitly supplying CC and such to pixman  
would help, though there still should be a way to pass in an explicit  
host tuple if you have an unusually-named toolchain.

-Scott