Public Review of the ACPI RISC-V IO Mapping Table (RIMT) Specification

[Sunil V L]

Greetings!

We are delighted to announce the commencement of the public review
period for the ACPI RISC-V IO Mapping Table (RIMT) Specification. The
30-day review period
begins today, January 13th 2025, and concludes on February 13th 2025.

The specification is available for download as a PDF at the
following link:
https://github.com/riscv-non-isa/riscv-acpi-rimt/releases/download/v1.0.0-rc5/rimt-spec.pdf

This document originates from the source available in the GitHub
https://github.com/riscv-non-isa/riscv-acpi-rimt

To respond to the public review, please either email comments to the
public RISC-V ISA-Dev mailing list at isa...@groups.riscv.org or add
issues to the GitHub repo at:
https://github.com/riscv-non-isa/riscv-acpi-rimt/issues

Throughout the public review period, we will collect corrections,
comments, and suggestions for consideration by the PRS TG.
Minor corrections and/or non-controversial changes will be incorporated
into the specification directly. Any unresolved issues or proposed
modifications will be detailed in the public review summary report.
Assuming no issues necessitate incompatible changes to the specification
under review, the PRS TG will propose that the updated specifications
be ratified by both the RISC-V Technical Steering Committee and the
RISC-V Board of Directors.

We extend our gratitude to all contributors for their dedicated efforts.

Regards,
Sunil V L
On behalf of PRS TG

[Heinrich Schuchardt]

Table 3. IOMMU Node
===================

Hardware ID
-----------

The values of ACPI IDs are defined by the ACPI ID registry
(https://uefi.org/ACPI_ID_List). This does not match with your use of
the term ACPI ID.

Please, use a terminology that is in line with ACPI's existing use.

It remains unmentioned if bytes 8 and 9 are used for the vendor ID or
for the device ID. Please, provide a precise description.

Best regards

Heinrich

[Sunil V L]

Hi Heinrich,

As per [1], ACPI ID should be of the form NNNN#### (8-bytes). It says,

"A valid ACPI ID must be of the form “NNNN####” where N is an uppercase
letter or a digit (‘0’-‘9’) and # is a hex digit."

Even [2] also mentions like below.
"Both PNP ID and ACPI ID consist of two parts: a Vendor ID, followed by a
product identifier. Each manufacturer of these devices must be assigned
an industry-unique Vendor ID (VID)."

However, I see your point that https://uefi.org/ACPI_ID_List lists as
ACPI ID which IMO should be "ACPI Vendor ID" since only Vendor ID is
assigned by the UEFI forum which is only 4 bytes. Isn't it something
UEFI forum should fix?

Thanks!
Sunil

[1] - https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#hid-hardware-id
[2] - https://uefi.org/PNP_ACPI_Registry

[Heinrich Schuchardt]

Could we reference [1] for details on creating a hardware ID instead of
adding our own definition which is not covering all of the cases and all
the detail described in [1]?

Best regards

Heinrich

[Sunil V L]

Okay. Will update. Thanks for the feedback!

Thanks,
Sunil