[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] Why is SeaBIOS used with -kernel?
From: |
Richard W.M. Jones |
Subject: |
Re: [Qemu-devel] Why is SeaBIOS used with -kernel? |
Date: |
Fri, 1 Apr 2016 09:44:56 +0100 |
User-agent: |
Mutt/1.5.20 (2009-12-10) |
On Fri, Apr 01, 2016 at 10:24:37AM +0200, Paolo Bonzini wrote:
> On 01/04/2016 10:14, Richard W.M. Jones wrote:
> > Found it: only CONFIG_MPTABLE=y was necessary. It boots with:
> >
> > # CONFIG_PIRTABLE is not set
> > CONFIG_MPTABLE=y
> > # CONFIG_SMBIOS is not set
> > # CONFIG_ACPI is not set
>
> If you add all three it should not give any slowdown and will provide
> full hardware features to the kernel. qboot does ACPI and PCI bus
> assignment (it doesn't do SMBIOS because I got bored debugging it. :))
Enabling all 4 adds about 2ms.
However the overhead of SeaBIOS is still down from 68ms to 18ms
(4.0% of total boot time down to 1.1%) so it's still a big gain.
I wonder how we can make use of this in qemu and downstream distros?
Can we have a bios-min.bin which is used with -kernel boots?
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages. http://libguestfs.org
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Richard W.M. Jones, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Paolo Bonzini, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Dr. David Alan Gilbert, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Gerd Hoffmann, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Richard W.M. Jones, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Gerd Hoffmann, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Richard W.M. Jones, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Richard W.M. Jones, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Paolo Bonzini, 2016/04/01
- Re: [Qemu-devel] Why is SeaBIOS used with -kernel?, Richard W.M. Jones, 2016/04/01