HI Andrew,

On Wed, Jan 19, 2022 at 6:31 AM Andrew Waterman <andrew@...> wrote:
>
> Hi Atish,
>
> I've got some minor feedback from the Architecture Review committee:
>
> We think that only the RV64 SBI should be ratified at this time.  The RV32 variants are likely to need some reworking (e.g., passing a physical address as an unsigned long precludes use of the full 34-bit physical-address space), and the RV32 variants aren't currently in high demand, anyway.

The RV32 physical address space limitation only impacts SBI RFENCE
calls and SBI HSM calls. A RV32 system can still use these calls as
long as their physical address space is within 4GB.

I suggest we document this RV32 limitation in SBI RFENCE and SBI HSM
chapters for SBI v1.0 and plan to address this in SBI v2.0.

>
> It would be helpful to add some non-normative text about what the SBI assumes about discovery.  For example, there's no SBI call to retrieve the value of the misa CSR--which is reasonable because the OS is presumably expected to retrieve this information from the DeviceTree--but readers who don't know that might find this surprising.

I agree with this suggestion. We got this question multiple times in
the past as well.

Regards,
Anup

>
> Thanks,
> Andrew
>
> On Wed, Jan 12, 2022 at 10:43 AM <atishp@...> wrote:
>>
>> I just realized that the below email was not delivered to unix
>> platform mailing list and
>> linux-riscv mailing list because of the attachment. Reseeding it again
>> without the
>> attachment. Apologies for the noise.
>>
>> -----------------------------------------------------------------------------------------------
>> We are delighted to announce the start of the public review period for
>> the Non-ISA Supervisor Binary Interface (SBI) specification. The
>> SBI specification is considered as frozen now as per the RISC-V International
>> policies.
>>
>> The review period begins today, Monday Jan 10, and ends on Monday
>> Jan 24 (inclusive).
>>
>> The specification can be found here
>> https://github.com/riscv-non-isa/riscv-sbi-doc/releases/download/v1.0-rc1/riscv-sbi.pdf
>>
>> which was generated from the source available in the following GitHub
>> repository:
>> https://github.com/riscv-non-isa/riscv-sbi-doc
>>
>> To respond to the public review, please either reply to this email or
>> send comments to the platform mailing list[1] or add issues to the
>> SBI GitHub repo[2]. We welcome all input and appreciate your time and
>> effort in helping us by reviewing the specification.
>>
>> During the public review period, corrections, comments, and
>> suggestions, will be gathered for review by the Platform HSC members. Any
>> minor corrections and/or uncontroversial changes will be incorporated
>> into the specification. Any remaining issues or proposed changes will
>> be addressed in the public review summary report. If there are no
>> issues that require incompatible changes to the public review
>> specification, the platform HSC will recommend the updated
>> specifications be approved and ratified by the RISC-V Technical
>> Steering Committee and the RISC-V Board of Directors.
>>
>> SBI specification is non-ISA specifications and will evolve over time
>> with new extensions as long as they are backward compatible. Any such
>> proposals for new extensions can be included in the future releases
>> after proper discussions in the platform working group meetings.
>>
>> Thanks to all the contributors for all their hard work.
>>
>> [1] tech-unixplatformspec@...
>> [2] https://github.com/riscv-non-isa/riscv-sbi-doc/issues
>>
>> Regards,
>> Atish Patra
>>
>>
>>
>>
>>