On 01/04/2016 10:44, Richard W.M. Jones wrote: > 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?
That's an interesting idea. We can look at it for 2.7. Paolo
