On Tue, Sep 1, 2020 at 11:48 AM Grant Likely <[email protected]> wrote: > > Early in EBBR discussions the decision was made that firmware should not > provide both DT and ACPI at the same time. The reasoning had been that > we didn't want to encourage 'hybrid' approaches where the OS tries to > consume both DT and ACPI descriptions. > > However, this fear has not so-far born out, and feedback has been that > requiring a boot-time switch to select either DT or ACPI is a support > issue for OS vendors. They would rather see ACPI (or DT) always turned > on if it is an option and the OS can choose to use it or not. > > Thoughts? Can the exclusive or be relaxed here?
The problem I have seen here from a OS support perspective is that you can get different levels of functionality on the OS side of things depending on which the OS chooses to priortise/support and that then just moves the support issue elsewhere. > Signed-off-by: Grant Likely <[email protected]> > --- > source/chapter2-uefi.rst | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/source/chapter2-uefi.rst b/source/chapter2-uefi.rst > index 066fefb..e0e71d6 100644 > --- a/source/chapter2-uefi.rst > +++ b/source/chapter2-uefi.rst > @@ -80,18 +80,12 @@ Configuration Tables > A UEFI system that complies with this specification may provide the > additional > tables via the EFI Configuration Table. > > -Compliant systems are required to provide one, but not both, of the following > +Compliant systems are required to provide at least one of the following > tables: > > - an Advanced Configuration and Power Interface [ACPI]_ table, or > - a Devicetree [DTSPEC]_ system description > > -EBBR systems must not provide both ACPI and Devicetree > -tables at the same time. > -Systems that support both interfaces must provide a configuration > -mechanism to select either ACPI or Devicetree, > -and must ensure only the selected interface is provided to the OS loader. > - > Devicetree > ^^^^^^^^^^ > > -- > 2.20.1 > > _______________________________________________ > boot-architecture mailing list > [email protected] > https://lists.linaro.org/mailman/listinfo/boot-architecture _______________________________________________ boot-architecture mailing list [email protected] https://lists.linaro.org/mailman/listinfo/boot-architecture
