On 1/10/22 18:02, Sunil V L wrote:

Hi All,
As we discussed in the Platform HSC meeting today, here is the document which details a new RISC-V specific EFI protocol.
https://github.com/riscv-non-isa/riscv-uefi/releases/download/0.1/EFI_RISCV_BOOT_PROTOCOL.pdf
Currently, the main use case of this protocol is to pass the boot hartid to the OS. But this can be extended in future if required. A PoC has been developed using EDK2 and Linux.
More details of this requirement and alternatives discussed are available at http://lists.infradead.org/pipermail/linux-riscv/2021-December/010604.html.
I request your review and will be great if you provide the feedback by 01/17.
Thanks!
Sunil

Dear Sunil,

thank you for drafting the protocol specification.

The interface of a protocol may change from version to version. Therefore I understand why there must be a path to convey this information. But using a function like EFI_RISCV_BOOT_PROTOCOL.GetProtocolVersion() makes accessing this information unnecessarily complicated. Instead consider adding a version field as first element of the interface like many other UEFI protocols do. This will also decrease the implementation size. For alignment reasons make this field UINT64. Other protocols call such a field "Revision". Please, provide a define for the current version. E.g.

#define EFI_RISCV_BOOT_PROTOCOL_REVISION 0x00010000
#define EFI_RISCV_BOOT_PROTOCOL_LATEST_VERSION \
EFI_RISCV_BOOT_PROTOCOL_REVISION

Function EFI_RISCV_BOOT_PROTOCOL.GetBootHartId() looks ok to me and is well described.

Best regards

Heinrich