Hey, On Wed, Jul 05, 2023 at 07:42:51PM +0800, Yunhui Cui wrote: > Add the description for ffitbl subnode. > > Signed-off-by: Yunhui Cui <cuiyunhui@xxxxxxxxxxxxx> > --- > .../devicetree/bindings/firmware/ffitbl.txt | 27 +++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 28 insertions(+) > create mode 100644 Documentation/devicetree/bindings/firmware/ffitbl.txt > > diff --git a/Documentation/devicetree/bindings/firmware/ffitbl.txt b/Documentation/devicetree/bindings/firmware/ffitbl.txt > new file mode 100644 > index 000000000000..c42368626199 > --- /dev/null > +++ b/Documentation/devicetree/bindings/firmware/ffitbl.txt > @@ -0,0 +1,27 @@ > +FFI(FDT FIRMWARE INTERFACE) driver > + > +Required properties: > + - entry : acpi or smbios root pointer, u64 > + - reg : acpi or smbios version, u32 > + > +Some bootloaders, such as Coreboot do not support EFI, > +only devicetree and some arches do not have a reserved > +address segment. Add "ffitbl" subnode to obtain ACPI RSDP > +and SMBIOS entry. Since the conversation on this stuff all seems to be going absolutely nowhere, the ACPI portion of this is intended for use on RISC-V in violation of the RISC-V ACPI specs. It also goes against the requirements of the platform spec. Quoting from [1]: | > Just so we're all on the same page, I just now asked Mark Himelstein | > of RISC-V International if there is anything in RISC-V standards that | > requires UEFI, and the answer is a solid "no." | | Huh? Firstly, running off to invoke RVI is not productive - they don't | maintain the various operating system kernels etc. | Secondly, that does not seem to be true. The platform spec mandates UEFI | for the OS-A server platform, alongside ACPI: | https://github.com/riscv/riscv-platform-specs/blob/main/riscv-platform-spec.adoc#32-boot-process | and the OS-A embedded platform needs to comply with EBBR & use DT: | https://github.com/riscv/riscv-platform-specs/blob/main/riscv-platform-spec.adoc#32-boot-process | | EBBR does say that systems must not provide both ACPI and DT to the OS | loader, but I am far from an expert on these kind of things & am not | sure where something like this where the DT "contains" ACPI would stand. | | The RISC-V ACPI spec also says "UEFI firmware is mandatory to support | ACPI": | https://github.com/riscv-non-isa/riscv-acpi/blob/master/riscv-acpi-guidance.adoc NAKed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Cheers, Conor. [1] - https://lore.kernel.org/linux-riscv/20230707-attach-conjuror-306d967347ce@wendy/
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