Re: [Qemu-devel] [PATCH] linux-user: Some scripts to create linux container using qemu-linux-user.

["Andreas Färber" <afaerber@suse.de>]

Am 14.01.2013 22:36, schrieb Laurent Vivier:
> * sudo qemu-update-binfmt.sh <target>
> 
> Call update-binfmts to install /bin/qemu-<target> as the binfmt interpreter.
> 
> * sudo qemu-create-lxc.sh <target>
> 
> This script mixes linux container, binfmt and qemu to create hybrid linux
> container : <target> container on an host kernel.
> 
> It will create "light" emulated virtual machine with several steps :
> - create a linux-user qemu-<target>
> - define it as the binfmt interpreter (using qemu-update-binfmt.sh).
> - install a base debian system under /containers/<target> using debootstrap.
>   and set a minimal configuration.
> - define a linux container
> 
> Then you can start the container using : sudo lxc-start -n virt<target>
> 
> TARGETS STATUS:
> 
> alpha: cannot run debootstrap --second stage*, but chroot is usable
> m68k: need patches from qemu-m68k, after that, all is working fine.
> mips: container can be started, but console login hangs.
> ppc: works fine*
> sparc: cannot run debootstrap --second stage (cannot fork)
> raspberrypi: (=armhf+raspbian) works*
> 
> * needs patches I sent to the mailing-list previously
> 
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
>  scripts/qemu-create-lxc.sh |  280 ++++++++++++++++++++++++++++++++++++++++++++
>  scripts/qemu-update-binfmt |   60 ++++++++++
>  2 files changed, 340 insertions(+)
>  create mode 100755 scripts/qemu-create-lxc.sh
>  create mode 100755 scripts/qemu-update-binfmt
[...]
> diff --git a/scripts/qemu-update-binfmt b/scripts/qemu-update-binfmt
> new file mode 100755
> index 0000000..ebdd971
> --- /dev/null
> +++ b/scripts/qemu-update-binfmt
> @@ -0,0 +1,60 @@
> +#!/bin/bash
> +
> +name="$1"
> +
> +# probe cpu type
> +cpu=`uname -m`
> +case "$cpu" in
> +  i386|i486|i586|i686|i86pc|BePC|x86_64)
> +    cpu="i386"
> +  ;;
> +  mips*)
> +    cpu="mips"
> +  ;;
> +  "Power Macintosh"|ppc64)
> +    cpu="ppc"
> +  ;;
> +  armv[4-9]*)
> +    cpu="arm"
> +  ;;
> +esac
> +
> +if [ "$name" = "$cpu" ]
> +then
> +    exit 0
> +fi
> +
> +case $name
> +in
> +    m68k)
> +        magic="\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x04"
> +        mask="\xff\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff"
> +        ;;
[snip]

Déjà vu... qemu-binfmt-conf.sh already has the magics hardcoded and
registers them via /proc. Please either reuse that script (with a new
parameter if needed) or move the data to a shared script used by both so
that not one is updated and the other forgotten.

The one thing I dislike about the existing script is that it hardcodes
each path to /usr/local/bin, which for openSUSE we need to override.
Your script hardcodes /bin in only one place instead.

Regards,
Andreas

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