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From: Peter Maydell <peter.maydell@linaro.org>
Date: Mon, 18 Aug 2014 13:45:49 +0100
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Subject: Re: [Qemu-devel] [PULL 00/24] Linux-user updates
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To: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Cc: Riku Voipio <riku.voipio@linaro.org>, QEMU Developers <qemu-devel@nongnu.org>

On 18 August 2014 13:38, Joakim Tjernlund <joakim.tjernlund@transmode.se> wrote:
> Peter Maydell <peter.maydell@linaro.org> wrote on 2014/08/18 12:58:48:
>> Well, binfmt-misc works fine for me as it is and presumably
>> for most people or we'd have had more complaints. So
>> breaking all those existing working setups is really something
>> we should avoid as much as possible.
>
> How do you use it? With LXC booting a VM with traditional init?

No. Just a straightforward chroot environment with a
statically linked qemu in it, and a binfmt_misc config like:

e104462:trusty:qemu$ cat /proc/sys/fs/binfmt_misc/qemu-arm
enabled
interpreter /usr/bin/qemu-arm-static
flags: OC
offset 0
magic 7f454c4601010100000000000000000002002800
mask ffffffffffffff00fffffffffffffffffeffffff

This works fine for the things I try to run in the chroot
(mostly test programs, also bash and basic command
line utilities).

> There are complaints which dists had to solve because QEMU didn't. Usually
> this is a separate static QEMU package/hack with a binfmt wrapper.
> Gentoo used to have one but this got removed.

I'm sure there are cases which don't work; but we should try
to find a way which allows us to make those work (with a
recommended change to binfmt misc registration) which
doesn't break the old configs in the process.

thanks
-- PMM