cross compiling kvm

cross compiling kvm

[Gerd Koenig]

hello,

can someone give me an information regarding the cross compile ability of kvm 
(especially for qemu)? 
Which is the first version of kvm, which is considered to be able to cross 
compile?

I tried KVM-28, which failed totally to cross-compile and I used KVM-53, which 
already had better support to cross compile, but still is not perfect (makes 
some assumptions about the host system, e.g. sdl-config).
With some minor changes in the configure script for qemu I got kvm-53 cross 
compiled. Unfortunatly kvm-53 doesn't run wit the preemption patches for 
2.6.21.6-rt21 but this is another question for later...

Of course, it can be possible, that I do something totally wrong.

This is my configure call:
./configure --arch=i386 --cross-prefix=/opt/crosstool/i686-pentium-linux-gnu/\
gcc-3.4.3-glibc-2.3.3/bin/i686-pentium-linux-gnu- \
--kerneldir=/home/gerdko/thinkiod_work/linux --disable-vnc-tls \
--prefix=/home/gerdko/thinkiod_work/install

you might ask, why I use a cross compiler for x86? Well, I want to use kvm on 
an embedded device, which doesn't have local gcc installed, so I need to 
compile everything on another host.

greetings,
gerd

Kontron Modular Computers GmbH
Geschaeftsfuehrer / Managing Directors: Ulrich Gehrmann, Thomas Sabisch 
Sitz der Gesellschaft / Registered Office: Kaufbeuren, Rechtsform / Legal: GmbH 
Amtsgericht / Local District Court Kempten, HRB Nr. / Trade Register No. 6195
 


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Re: cross compiling kvm

[Jerone Young]

On Mon, 2007-11-26 at 11:57 +0100, Gerd Koenig wrote:
> hello,
> 
> can someone give me an information regarding the cross compile ability of kvm 
> (especially for qemu)? 
> Which is the first version of kvm, which is considered to be able to cross 
> compile?

It would be one of the newer versions. I started to sending cross
compile stuff probably around kvm-47 timeframe (I barely remember).
Definitely not kvm-28 though.

> 
> I tried KVM-28, which failed totally to cross-compile and I used KVM-53, which 
> already had better support to cross compile, but still is not perfect (makes 
> some assumptions about the host system, e.g. sdl-config).
> With some minor changes in the configure script for qemu I got kvm-53 cross 
> compiled. Unfortunatly kvm-53 doesn't run wit the preemption patches for 
> 2.6.21.6-rt21 but this is another question for later...
> 
> Of course, it can be possible, that I do something totally wrong.
> 
> This is my configure call:
> ./configure --arch=i386 --cross-prefix=/opt/crosstool/i686-pentium-linux-gnu/\
> gcc-3.4.3-glibc-2.3.3/bin/i686-pentium-linux-gnu- \
> --kerneldir=/home/gerdko/thinkiod_work/linux --disable-vnc-tls \
> --prefix=/home/gerdko/thinkiod_work/install
> 
> you might ask, why I use a cross compiler for x86? Well, I want to use kvm on 
> an embedded device, which doesn't have local gcc installed, so I need to 
> compile everything on another host.

I have found that your going to want to add "--with-patched-kernel" to
your command line also.

To solve your SDL issue you probably want to cross compile a version SDL
in a directory .. then add to the --qemu-cflags option &
--qemu-ldflags. Same whould go for stuff like ZLib.

./configure --arch=i386
--cross-prefix=/opt/crosstool/i686-pentium-linux-gnu/\
gcc-3.4.3-glibc-2.3.3/bin/i686-pentium-linux-gnu- \
--kerneldir=/home/gerdko/thinkiod_work/linux --disable-vnc-tls \
--prefix=/home/gerdko/thinkiod_work/install \
--with-patched-kernel \
--qemu-cflags="--static -I <SDL_DIR>/include -I <zlib_dir>/lib" \   
--qemu-ldflags="-L <SDL_DIR>/lib -L <zlib_dir>/include"

Another thing that you need to sneak in is that your going to need is
adding "--static" flag into the qemu compilation (which I do in
--qemu-cflags in the example).

Cross compiling qemu is a little bit of a pain.due to the external
dependencies. But it is possible.

Now just to add some more info to be over verbose. Way back we hacked
something together for powerpc and we had to manually compile cross
compile qemu doing the following:
	
        export LDFLAGS="-L/home/public/zlib-ppc/lib"
        export CFLAGS="-I/home/public/zlib-ppc/include"
       
       ./configure \
               --target-list=ppcemb-softmmu \
               --cpu=powerpc \
               --disable-gcc-check \
               --disable-sdl \
               --disable-gfx-check \
               --disable-kqemu \
               --cpu=powerpc \
               --cross-prefix=powerpc-440-linux-gnu- \
               --static
        
We didn't use SDL, but we did run into the same problem with zlib. Then
we just copied the executable over.

Hope that helps.

> 
> greetings,
> gerd
> 
> Kontron Modular Computers GmbH
> Geschaeftsfuehrer / Managing Directors: Ulrich Gehrmann, Thomas Sabisch 
> Sitz der Gesellschaft / Registered Office: Kaufbeuren, Rechtsform / Legal: GmbH 
> Amtsgericht / Local District Court Kempten, HRB Nr. / Trade Register No. 6195
> 
> 
> 
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> Defy all challenges. Microsoft(R) Visual Studio 2005.
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Re: cross compiling kvm

[Gerd Koenig]

Hi Jerone,

On Monday 26 November 2007, Jerone Young wrote:
> On Mon, 2007-11-26 at 11:57 +0100, Gerd Koenig wrote:
> > hello,

> > Which is the first version of kvm, which is considered to be able to
> > cross compile?
>
> It would be one of the newer versions. I started to sending cross
> compile stuff probably around kvm-47 timeframe (I barely remember).
> Definitely not kvm-28 though.
>
thanks for the info! So I will continue to work with kvm-53. The thing is, 
that some people say, that it is necessary to use a patched version of KVM by 
using it with the realtime preemption patches. But this is an issue I will 
investigate after a successful installation of kvm on our target.

> > Of course, it can be possible, that I do something totally wrong.
> >
> > This is my configure call:
> > ./configure --arch=i386
> > --cross-prefix=/opt/crosstool/i686-pentium-linux-gnu/\
> > gcc-3.4.3-glibc-2.3.3/bin/i686-pentium-linux-gnu- \
> > --kerneldir=/home/gerdko/thinkiod_work/linux --disable-vnc-tls \
> > --prefix=/home/gerdko/thinkiod_work/install
> >
> > you might ask, why I use a cross compiler for x86? Well, I want to use
> > kvm on an embedded device, which doesn't have local gcc installed, so I
> > need to compile everything on another host.
>
> I have found that your going to want to add "--with-patched-kernel" to
> your command line also.
>
Why is this so? I understood, if I want to compile the kvm package, including 
the kernel modules, I don't have to use the "--with-patched-kernel". Am I 
wrong? I'm a bit puzzled at the moment, as it seems, that 
the "--with-patched-kernel" switch is incompatible with "--kerneldir" ??
kerneldir is a path to my patched 2.6.21.6-rt21 preemptible-kernel for our 
target, by the way.

>
> To solve your SDL issue you probably want to cross compile a version SDL
> in a directory .. then add to the --qemu-cflags option &
> --qemu-ldflags. Same whould go for stuff like ZLib.
>
yes, I did so. And it seems to work.
But there is still a problem with the configure script, as it assumes to 
search for sdl-config on the development host. A minor problem though and 
easy to fix... 
I could send a patch afterwards, when I found a common solution...

>
> ./configure --arch=i386
> --cross-prefix=/opt/crosstool/i686-pentium-linux-gnu/\
> gcc-3.4.3-glibc-2.3.3/bin/i686-pentium-linux-gnu- \
> --kerneldir=/home/gerdko/thinkiod_work/linux --disable-vnc-tls \
> --prefix=/home/gerdko/thinkiod_work/install \
> --with-patched-kernel \
> --qemu-cflags="--static -I <SDL_DIR>/include -I <zlib_dir>/lib" \
> --qemu-ldflags="-L <SDL_DIR>/lib -L <zlib_dir>/include"
>
> Another thing that you need to sneak in is that your going to need is
> adding "--static" flag into the qemu compilation (which I do in
> --qemu-cflags in the example).
>
> Cross compiling qemu is a little bit of a pain.due to the external
> dependencies. But it is possible.
phew. yes it is ;-)


> Hope that helps.
thank you!

greetings,
gerd

Kontron Modular Computers GmbH
Geschaeftsfuehrer / Managing Directors: Ulrich Gehrmann, Thomas Sabisch 
Sitz der Gesellschaft / Registered Office: Kaufbeuren, Rechtsform / Legal: GmbH 
Amtsgericht / Local District Court Kempten, HRB Nr. / Trade Register No. 6195
 


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This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
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