Re: Design doc of adding ACPI support for arm64 on Xen - version 2

[Ian Campbell <ian.campbell@citrix.com>]

On Wed, 2015-09-02 at 12:39 +0100, Julien Grall wrote:
> Hi Ian,
> 
> On 02/09/15 12:30, Ian Campbell wrote:
> > > Although, when running on Xen, FreeBSD is creating a Xen console by
> > > default with the higher priority. It will be grabbed by FreeBSD as 
> > > the
> > > default one.
> > 
> > ... Linux should be doing the same. The problem is that the existing 
> > code
> > to call add_preferred_console doesn't happen early enough on ARM
> > 
> > Someone (you? Ard? Stefano?) has a patch to move Xen detection in Linux
> > earlier ages ago, but I think it failed to actually get in.
> 
> The patch is present in Linux 4.2:

Not the patch I was thinking of, but since it achieves the end goal another
way: Yeehaw!

> commit f1dddd118c555508ce383b7262f4e6440927bdf4
> Author: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Date:   Wed May 6 14:14:22 2015 +0000
> 
>     xen/arm: allow console=hvc0 to be omitted for guests
>     
>     From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>     
>     This patch registers hvc0 as the preferred console if no console
>     has been specified explicitly on the kernel command line.
>     
>     The purpose is to allow platform agnostic kernels and boot images
>     (such as distro installers) to boot in a Xen/ARM domU without the
>     need to modify the command line by hand.
>     
>     Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>     Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>     Reviewed-by: Julien Grall <julien.grall@linaro.org>
> 
>