Re: [RFC PATCH V2 0/1] RISCV_EFI_BOOT_PROTOCOL support in linux

[Sunil V L <sunilvl@ventanamicro.com>]

On Tue, Mar 22, 2022 at 06:32:22PM -0700, Palmer Dabbelt wrote:
> On Thu, 03 Mar 2022 06:59:43 PST (-0800), sunilvl@ventanamicro.com wrote:
> > This patch adds support for getting the boot hart ID using new
> > RISCV_EFI_BOOT_PROTOCOL in linux efi stub. While there is an existing
> > solution of passing the boot hart ID through Device Tree, it doesn't work
> > for ACPI. Hence an EFI protocol protocol is recommended which works for
> > both DT and ACPI based platforms.
> > 
> > The latest draft spec of this new protocol is available at
> > https://github.com/riscv-non-isa/riscv-uefi/releases/download/1.0-rc2/RISCV_UEFI_PROTOCOL-spec.pdf
> 
> This looks fine to me, but we need the spec folk to commit to this being a
> stable interface before we can start using it.  Historically that's been
> "frozen" for RISC-V specs, but I'm not sure how that all fits together in
> EFI land as IIUC we also have to follow the UEFI forum's process.  Last I
> checked you guys understood that better than I did, so

Thank you Palmer. The specification is in frozen state now. 
http://lists.infradead.org/pipermail/linux-riscv/2022-March/013431.html.

Thanks
Sunil
> 
> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # pending spec freeze
> 
> I had a minor comment about the error message, as well.
> 
> Thanks!
> 
> > This linux ptach can be found in:
> > riscv_boot_protocol_rfc_v2 branch at
> > https://github.com/vlsunil/linux.git
> > 
> > This is tested in qemu with u-boot 2022.04.rc3.
> > 
> > Changes since V1:
> >   - Rebased to get the "Fix get_boot_hartid_from_fdt() return value"
> >     patch
> >   - Removed mixed_mode member
> >   - Separated return value and status.
> > 
> > Sunil V L (1):
> >   riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOL
> > 
> >  drivers/firmware/efi/libstub/efistub.h    |  7 ++++++
> >  drivers/firmware/efi/libstub/riscv-stub.c | 29 +++++++++++++++++++----
> >  include/linux/efi.h                       |  1 +
> >  3 files changed, 32 insertions(+), 5 deletions(-)