On Wed, Feb 01, 2017 at 12:37:39PM +0100, Igor Mammedov wrote: > On Tue, 31 Jan 2017 20:17:02 +0200 > "Michael S. Tsirkin" <m...@redhat.com> wrote: > > > On Tue, Jan 31, 2017 at 05:28:57PM +0100, Laszlo Ersek wrote: > > > The ACPI 6.1 spec says, > > > > > > - DSDT: [...] If the X_DSDT field contains a non-zero value then this > > > field must be zero. > > > - X_DSDT: [...] If the DSDT field contains a non-zero value then this > > > field must be zero. > > > > But that's only 6.1. 6.0 and earlier did not say this. > > The errata they wanted to address was: > > 1393 In FADT: if X_DSDT field is non-zero, DSDT > > field should be ignored or deprecated > > > > I would class this as a spec bug. > > > > The same applies to X_PM1a_EVT_BLK and co, > for example 5.1 spec "This is a required > field." > > And looks like Windows implemented it as mandatory > to boot perhaps to be compatible with 5.1 and earlier > specs. > > It appears fw would be forced to fill fields depending > on table revision.
Or just do what every hardware vendor does: 1. write according to spec 2. test a bunch of OSes, fix crashes -- MST
