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

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

On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I suggest to have a RISC-V EFI Protocols Specification. This spec accommodates EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V platform, and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we should create an issue in bugzilla.tianocore.org and create a Mantis entry to get it merged into the UEFI specification.

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>; Jessica
Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On Mon, Jan 10, 2022 at 06:27:37PM +0100, Heinrich Schuchardt wrote:

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.

Hi Heinrich,
Thank you very much for your constant feedback and pointers while
drafting this spec.

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

This makes perfect sense. Will update the spec.

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

Jessica has given an input to change the parameter from UINT32 * to
UINTN * since mhartid can be of XLEN. I think this is also a great
feedback. Will incorporate it in the next update of the spec.

Thanks!
Sunil

Best regards

Heinrich

On Tue, Jan 11, 2022 at 01:07:33AM +0000, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I suggest to have a RISC-V EFI Protocols Specification. This spec accommodates EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V platform, and those we had implemented in edk2.

Sure, Abner. Makes sense. Let me update the spec.

Thanks
Sunil

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>; Jessica
Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On Tue, Jan 11, 2022 at 02:11:40AM +0000, Chang, Abner (HPS SW/FW Technologist) wrote:

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 9:20 AM
To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Cc: tech-unixplatformspec@...; Anup Patel
<apatel@...>; Atish Patra <atishp@...>; Jessica
Clarke <jrtc27@...>; Sunil V L <sunilvl@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL



On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I

suggest to have a RISC-V EFI Protocols Specification. This spec accommodates
EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V platform,
and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Oops... RiscVEdk2Sbi was implemented as library for now and the plan is to rap it as PPI/protocol, bad memory.

Even if there are no other RISC-V protocols today, Abner's suggestion
will allow us to add them in future to the same document.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we should create
an
issue in bugzilla.tianocore.org and create a Mantis entry to get it
merged into the UEFI specification.

I don't think this would be accepted by UEFI forum. This is RISC-V specific protocol however, UEFI protocol is the abstract interface for platform and architecture. Unless you can come out a abstract interface that can accommodate different processor/platform architectures (if they also need this).

We don't really need to merge the entire protocol to the UEFI spec. We
need to maintain this within RISC-V organization like other RISC-V specs
and add as a requirement in the platform spec. We can probably add a
link under uefi.org/uefi and provide a reference in section 2.3.7.1.
UEFI allows us to do like this (ex: TCG2 protocols) and it may be better
since we do not need to update the UEFI spec for any new protocols
specific to RISC-V in future.

What do you think? Do you see any issue with this approach?

Thanks
Sunil

Regards,
Abner

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>; Jessica
Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On 1/11/22 07:02, Sunil V L wrote:

On Tue, Jan 11, 2022 at 02:11:40AM +0000, Chang, Abner (HPS SW/FW Technologist) wrote:

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 9:20 AM
To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Cc: tech-unixplatformspec@...; Anup Patel
<apatel@...>; Atish Patra <atishp@...>; Jessica
Clarke <jrtc27@...>; Sunil V L <sunilvl@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL



On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I

suggest to have a RISC-V EFI Protocols Specification. This spec accommodates
EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V platform,
and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Oops... RiscVEdk2Sbi was implemented as library for now and the plan is to rap it as PPI/protocol, bad memory.

Even if there are no other RISC-V protocols today, Abner's suggestion
will allow us to add them in future to the same document.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we should create
an
issue in bugzilla.tianocore.org and create a Mantis entry to get it
merged into the UEFI specification.

I don't think this would be accepted by UEFI forum. This is RISC-V specific protocol however, UEFI protocol is the abstract interface for platform and architecture. Unless you can come out a abstract interface that can accommodate different processor/platform architectures (if they also need this).

We don't really need to merge the entire protocol to the UEFI spec. We
need to maintain this within RISC-V organization like other RISC-V specs
and add as a requirement in the platform spec. We can probably add a
link under uefi.org/uefi and provide a reference in section 2.3.7.1.
UEFI allows us to do like this (ex: TCG2 protocols) and it may be better
since we do not need to update the UEFI spec for any new protocols
specific to RISC-V in future.

What do you think? Do you see any issue with this approach?

The TCG2 protocol is only a UEFI extension (see UEFI spec 2.9, p.68) and
not required to claim UEFI compatibility.

If you put a protocol into the UEFI specification, you can be sure that
EDK II will implement it. And not firmware can claim to be UEFI
compliant without it.

I would prefer if every UEFI protocol that is absolutely essential for
booting were required by the UEFI specification. If the details are
maintained inside the UEFI specification or outside, does not matter to me.

Best regards

Heirnich

Thanks
Sunil

Regards,
Abner

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>; Jessica
Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On Mon, Jan 10, 2022 at 11:57 PM Chang, Abner (HPS SW/FW Technologist)
<abner.chang@...> wrote:

-----Original Message-----
From: Heinrich Schuchardt <xypron.glpk@...>
Sent: Tuesday, January 11, 2022 3:50 PM
To: Sunil V L <sunilvl@...>; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>
Cc: Heinrich Schuchardt <heinrich.schuchardt@...>; tech-
unixplatformspec@...; Anup Patel <apatel@...>;
Atish Patra <atishp@...>; Jessica Clarke <jrtc27@...>
Subject: Re: [RISC-V] [tech-unixplatformspec] Review request: New
EFI_RISCV_BOOT_PROTOCOL

On 1/11/22 07:02, Sunil V L wrote:

On Tue, Jan 11, 2022 at 02:11:40AM +0000, Chang, Abner (HPS SW/FW

Technologist) wrote:

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 9:20 AM
To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Cc: tech-unixplatformspec@...; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>; Sunil V L <sunilvl@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL



On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I

suggest to have a RISC-V EFI Protocols Specification. This spec

accommodates

EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V

platform,

and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Oops... RiscVEdk2Sbi was implemented as library for now and the plan is

to rap it as PPI/protocol, bad memory.

Even if there are no other RISC-V protocols today, Abner's suggestion
will allow us to add them in future to the same document.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we should

create

an
issue in bugzilla.tianocore.org and create a Mantis entry to get it
merged into the UEFI specification.

I don't think this would be accepted by UEFI forum. This is RISC-V specific

protocol however, UEFI protocol is the abstract interface for platform and
architecture. Unless you can come out a abstract interface that can
accommodate different processor/platform architectures (if they also need
this).

We don't really need to merge the entire protocol to the UEFI spec. We
need to maintain this within RISC-V organization like other RISC-V specs
and add as a requirement in the platform spec. We can probably add a
link under uefi.org/uefi and provide a reference in section 2.3.7.1.
UEFI allows us to do like this (ex: TCG2 protocols) and it may be better
since we do not need to update the UEFI spec for any new protocols
specific to RISC-V in future.

What do you think? Do you see any issue with this approach?

The TCG2 protocol is only a UEFI extension (see UEFI spec 2.9, p.68) and
not required to claim UEFI compatibility.

If you put a protocol into the UEFI specification, you can be sure that
EDK II will implement it. And not firmware can claim to be UEFI
compliant without it.

To spec out something in either UEFI or RISC-V specific spec is actually the same to RISC-V edk2 port IMO, if those are the mandatory protocols.
Edk2 RISC-V port should compliant with the firmware spec defined by either specs, unless the spec says the protocol is specifically to uboot but it is optional for other firmware solutions.

I think it would be better to enforce the mandatory requirement
explicitly in the UEFI spec. The actual content of the protocol can be
hosted under RISC-V.

Regards,
Abner

I would prefer if every UEFI protocol that is absolutely essential for
booting were required by the UEFI specification. If the details are
maintained inside the UEFI specification or outside, does not matter to me.

Best regards

Heirnich

Thanks
Sunil

Regards,
Abner

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On Tue, Jan 11, 2022 at 12:48:16PM -0800, Atish Kumar Patra wrote:

On Mon, Jan 10, 2022 at 11:57 PM Chang, Abner (HPS SW/FW Technologist)
<abner.chang@...> wrote:

-----Original Message-----
From: Heinrich Schuchardt <xypron.glpk@...>
Sent: Tuesday, January 11, 2022 3:50 PM
To: Sunil V L <sunilvl@...>; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>
Cc: Heinrich Schuchardt <heinrich.schuchardt@...>; tech-
unixplatformspec@...; Anup Patel <apatel@...>;
Atish Patra <atishp@...>; Jessica Clarke <jrtc27@...>
Subject: Re: [RISC-V] [tech-unixplatformspec] Review request: New
EFI_RISCV_BOOT_PROTOCOL

On 1/11/22 07:02, Sunil V L wrote:

On Tue, Jan 11, 2022 at 02:11:40AM +0000, Chang, Abner (HPS SW/FW

Technologist) wrote:

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 9:20 AM
To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Cc: tech-unixplatformspec@...; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>; Sunil V L <sunilvl@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL



On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I

suggest to have a RISC-V EFI Protocols Specification. This spec

accommodates

EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V

platform,

and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Oops... RiscVEdk2Sbi was implemented as library for now and the plan is

to rap it as PPI/protocol, bad memory.

Even if there are no other RISC-V protocols today, Abner's suggestion
will allow us to add them in future to the same document.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we should

create

an
issue in bugzilla.tianocore.org and create a Mantis entry to get it
merged into the UEFI specification.

I don't think this would be accepted by UEFI forum. This is RISC-V specific

protocol however, UEFI protocol is the abstract interface for platform and
architecture. Unless you can come out a abstract interface that can
accommodate different processor/platform architectures (if they also need
this).

We don't really need to merge the entire protocol to the UEFI spec. We
need to maintain this within RISC-V organization like other RISC-V specs
and add as a requirement in the platform spec. We can probably add a
link under uefi.org/uefi and provide a reference in section 2.3.7.1.
UEFI allows us to do like this (ex: TCG2 protocols) and it may be better
since we do not need to update the UEFI spec for any new protocols
specific to RISC-V in future.

What do you think? Do you see any issue with this approach?

The TCG2 protocol is only a UEFI extension (see UEFI spec 2.9, p.68) and
not required to claim UEFI compatibility.

If you put a protocol into the UEFI specification, you can be sure that
EDK II will implement it. And not firmware can claim to be UEFI
compliant without it.

To spec out something in either UEFI or RISC-V specific spec is actually the same to RISC-V edk2 port IMO, if those are the mandatory protocols.
Edk2 RISC-V port should compliant with the firmware spec defined by either specs, unless the spec says the protocol is specifically to uboot but it is optional for other firmware solutions.

I think it would be better to enforce the mandatory requirement
explicitly in the UEFI spec. The actual content of the protocol can be
hosted under RISC-V.

Hi All,
I think I have addressed your comments. Please take a look at
https://github.com/riscv-non-isa/riscv-uefi/releases/download/0.2/EFI_RISCV_PROTOCOL-spec.pdf.
If you think it is fine, I plan to get it reviewed once with Ard and
linux-riscv also where this solution was proposed originally.

We may not be able to add to mandatory UEFI section 2.6.1 but we can
try adding to 2.6.2 and mandate it via platform spec like we do for
PCI protocol.

Atish, should this be added to EBBR also?

Thanks
Sunil

Regards,
Abner

I would prefer if every UEFI protocol that is absolutely essential for
booting were required by the UEFI specification. If the details are
maintained inside the UEFI specification or outside, does not matter to me.

Best regards

Heirnich

Thanks
Sunil

Regards,
Abner

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On Wed, Jan 12, 2022 at 12:04 AM Sunil V L <sunilvl@...> wrote:

On Tue, Jan 11, 2022 at 12:48:16PM -0800, Atish Kumar Patra wrote:

On Mon, Jan 10, 2022 at 11:57 PM Chang, Abner (HPS SW/FW Technologist)
<abner.chang@...> wrote:

-----Original Message-----
From: Heinrich Schuchardt <xypron.glpk@...>
Sent: Tuesday, January 11, 2022 3:50 PM
To: Sunil V L <sunilvl@...>; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>
Cc: Heinrich Schuchardt <heinrich.schuchardt@...>; tech-
unixplatformspec@...; Anup Patel <apatel@...>;
Atish Patra <atishp@...>; Jessica Clarke <jrtc27@...>
Subject: Re: [RISC-V] [tech-unixplatformspec] Review request: New
EFI_RISCV_BOOT_PROTOCOL

On 1/11/22 07:02, Sunil V L wrote:

On Tue, Jan 11, 2022 at 02:11:40AM +0000, Chang, Abner (HPS SW/FW

Technologist) wrote:

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 9:20 AM
To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Cc: tech-unixplatformspec@...; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>; Sunil V L <sunilvl@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL



On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I

suggest to have a RISC-V EFI Protocols Specification. This spec

accommodates

EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V

platform,

and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Oops... RiscVEdk2Sbi was implemented as library for now and the plan is

to rap it as PPI/protocol, bad memory.

Even if there are no other RISC-V protocols today, Abner's suggestion
will allow us to add them in future to the same document.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we should

create

an
issue in bugzilla.tianocore.org and create a Mantis entry to get it
merged into the UEFI specification.

I don't think this would be accepted by UEFI forum. This is RISC-V specific

protocol however, UEFI protocol is the abstract interface for platform and
architecture. Unless you can come out a abstract interface that can
accommodate different processor/platform architectures (if they also need
this).

We don't really need to merge the entire protocol to the UEFI spec. We
need to maintain this within RISC-V organization like other RISC-V specs
and add as a requirement in the platform spec. We can probably add a
link under uefi.org/uefi and provide a reference in section 2.3.7.1.
UEFI allows us to do like this (ex: TCG2 protocols) and it may be better
since we do not need to update the UEFI spec for any new protocols
specific to RISC-V in future.

What do you think? Do you see any issue with this approach?

The TCG2 protocol is only a UEFI extension (see UEFI spec 2.9, p.68) and
not required to claim UEFI compatibility.

If you put a protocol into the UEFI specification, you can be sure that
EDK II will implement it. And not firmware can claim to be UEFI
compliant without it.

To spec out something in either UEFI or RISC-V specific spec is actually the same to RISC-V edk2 port IMO, if those are the mandatory protocols.
Edk2 RISC-V port should compliant with the firmware spec defined by either specs, unless the spec says the protocol is specifically to uboot but it is optional for other firmware solutions.

I think it would be better to enforce the mandatory requirement
explicitly in the UEFI spec. The actual content of the protocol can be
hosted under RISC-V.

Hi All,
I think I have addressed your comments. Please take a look at
https://github.com/riscv-non-isa/riscv-uefi/releases/download/0.2/EFI_RISCV_PROTOCOL-spec.pdf.
If you think it is fine, I plan to get it reviewed once with Ard and
linux-riscv also where this solution was proposed originally.

We may not be able to add to mandatory UEFI section 2.6.1 but we can
try adding to 2.6.2 and mandate it via platform spec like we do for
PCI protocol.

Sounds good. One minor comment:

"While there can be a solution using /chosen node in DT based systems
to pass this information, a simple and common interface across DT and
ACPI platforms is desired on UEFI platforms to retrieve such
information."

The following statement should be improved to indicate that /chosen
node is an existing solution. However, it will not work for ACPI.
EFI_RISCV_BOOT_PROTOCOL should be the preferred over /chosen node
option for both DT/ACPI platforms.

Atish, should this be added to EBBR also?

Yeah. RISC-V Multiprocessor Startup Protocol should be updated.
EFI_RISCV_BOOT_PROTOCOL should be preferred first. In absence of this,
firmware must
provide the /chosen hartid for the DT based platforms.

I guess you don't need to update EBBR right away. Once this is
accepted in the UEFI forum, EBBR can be updated.

Thanks
Sunil

Regards,
Abner

I would prefer if every UEFI protocol that is absolutely essential for
booting were required by the UEFI specification. If the details are
maintained inside the UEFI specification or outside, does not matter to me.

Best regards

Heirnich

Thanks
Sunil

Regards,
Abner

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On Wed, Jan 12, 2022 at 05:53:15PM -0800, Atish Kumar Patra wrote:

On Wed, Jan 12, 2022 at 12:04 AM Sunil V L <sunilvl@...> wrote:

On Tue, Jan 11, 2022 at 12:48:16PM -0800, Atish Kumar Patra wrote:

On Mon, Jan 10, 2022 at 11:57 PM Chang, Abner (HPS SW/FW Technologist)
<abner.chang@...> wrote:

-----Original Message-----
From: Heinrich Schuchardt <xypron.glpk@...>
Sent: Tuesday, January 11, 2022 3:50 PM
To: Sunil V L <sunilvl@...>; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>
Cc: Heinrich Schuchardt <heinrich.schuchardt@...>; tech-
unixplatformspec@...; Anup Patel <apatel@...>;
Atish Patra <atishp@...>; Jessica Clarke <jrtc27@...>
Subject: Re: [RISC-V] [tech-unixplatformspec] Review request: New
EFI_RISCV_BOOT_PROTOCOL

On 1/11/22 07:02, Sunil V L wrote:

On Tue, Jan 11, 2022 at 02:11:40AM +0000, Chang, Abner (HPS SW/FW

Technologist) wrote:

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 9:20 AM
To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Cc: tech-unixplatformspec@...; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>; Sunil V L <sunilvl@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL



On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist) wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL specifically, I

suggest to have a RISC-V EFI Protocols Specification. This spec

accommodates

EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-V

platform,

and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Oops... RiscVEdk2Sbi was implemented as library for now and the plan is

to rap it as PPI/protocol, bad memory.

Even if there are no other RISC-V protocols today, Abner's suggestion
will allow us to add them in future to the same document.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we should

create

an
issue in bugzilla.tianocore.org and create a Mantis entry to get it
merged into the UEFI specification.

I don't think this would be accepted by UEFI forum. This is RISC-V specific

protocol however, UEFI protocol is the abstract interface for platform and
architecture. Unless you can come out a abstract interface that can
accommodate different processor/platform architectures (if they also need
this).

We don't really need to merge the entire protocol to the UEFI spec. We
need to maintain this within RISC-V organization like other RISC-V specs
and add as a requirement in the platform spec. We can probably add a
link under uefi.org/uefi and provide a reference in section 2.3.7.1.
UEFI allows us to do like this (ex: TCG2 protocols) and it may be better
since we do not need to update the UEFI spec for any new protocols
specific to RISC-V in future.

What do you think? Do you see any issue with this approach?

The TCG2 protocol is only a UEFI extension (see UEFI spec 2.9, p.68) and
not required to claim UEFI compatibility.

If you put a protocol into the UEFI specification, you can be sure that
EDK II will implement it. And not firmware can claim to be UEFI
compliant without it.

To spec out something in either UEFI or RISC-V specific spec is actually the same to RISC-V edk2 port IMO, if those are the mandatory protocols.
Edk2 RISC-V port should compliant with the firmware spec defined by either specs, unless the spec says the protocol is specifically to uboot but it is optional for other firmware solutions.

I think it would be better to enforce the mandatory requirement
explicitly in the UEFI spec. The actual content of the protocol can be
hosted under RISC-V.

Hi All,
I think I have addressed your comments. Please take a look at
https://github.com/riscv-non-isa/riscv-uefi/releases/download/0.2/EFI_RISCV_PROTOCOL-spec.pdf.
If you think it is fine, I plan to get it reviewed once with Ard and
linux-riscv also where this solution was proposed originally.

We may not be able to add to mandatory UEFI section 2.6.1 but we can
try adding to 2.6.2 and mandate it via platform spec like we do for
PCI protocol.

Sounds good. One minor comment:

"While there can be a solution using /chosen node in DT based systems
to pass this information, a simple and common interface across DT and
ACPI platforms is desired on UEFI platforms to retrieve such
information."

The following statement should be improved to indicate that /chosen
node is an existing solution. However, it will not work for ACPI.
EFI_RISCV_BOOT_PROTOCOL should be the preferred over /chosen node
option for both DT/ACPI platforms.

Thanks. Updated as per your suggestion.
https://github.com/riscv-non-isa/riscv-uefi/releases/download/0.3/EFI_RISCV_PROTOCOL-spec.pdf

I will work with you, Heinrich and Abner to get an codefirst ECR to
USWG.

Atish, should this be added to EBBR also?

Yeah. RISC-V Multiprocessor Startup Protocol should be updated.
EFI_RISCV_BOOT_PROTOCOL should be preferred first. In absence of this,
firmware must
provide the /chosen hartid for the DT based platforms.

I guess you don't need to update EBBR right away. Once this is
accepted in the UEFI forum, EBBR can be updated.

Sure.

Thanks
Sunil

Thanks
Sunil

Regards,
Abner

I would prefer if every UEFI protocol that is absolutely essential for
booting were required by the UEFI specification. If the details are
maintained inside the UEFI specification or outside, does not matter to me.

Best regards

Heirnich

Thanks
Sunil

Regards,
Abner

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt <heinrich.schuchardt@...>
Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner (HPS SW/FW
Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra <atishp@...>;

Jessica

Clarke <jrtc27@...>
Subject: Re: Review request: New EFI_RISCV_BOOT_PROTOCOL

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

On Thu, Jan 13, 2022 at 10:13:04AM +0000, Chang, Abner (HPS SW/FW Technologist) wrote:

-----Original Message-----
From: Sunil V L <sunilvl@...>
Sent: Thursday, January 13, 2022 5:48 PM
To: Atish Kumar Patra <atishp@...>
Cc: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>;
Heinrich Schuchardt <xypron.glpk@...>; Heinrich Schuchardt
<heinrich.schuchardt@...>; tech-
unixplatformspec@...; Anup Patel <apatel@...>;
Jessica Clarke <jrtc27@...>
Subject: Re: [RISC-V] [tech-unixplatformspec] Review request: New
EFI_RISCV_BOOT_PROTOCOL

On Wed, Jan 12, 2022 at 05:53:15PM -0800, Atish Kumar Patra wrote:

On Wed, Jan 12, 2022 at 12:04 AM Sunil V L <sunilvl@...>

wrote:

On Tue, Jan 11, 2022 at 12:48:16PM -0800, Atish Kumar Patra wrote:

On Mon, Jan 10, 2022 at 11:57 PM Chang, Abner (HPS SW/FW

Technologist)

<abner.chang@...> wrote:

-----Original Message-----
From: Heinrich Schuchardt <xypron.glpk@...>
Sent: Tuesday, January 11, 2022 3:50 PM
To: Sunil V L <sunilvl@...>; Chang, Abner (HPS

SW/FW

Technologist) <abner.chang@...>
Cc: Heinrich Schuchardt <heinrich.schuchardt@...>;

tech-

unixplatformspec@...; Anup Patel

<apatel@...>;

Atish Patra <atishp@...>; Jessica Clarke

<jrtc27@...>

Subject: Re: [RISC-V] [tech-unixplatformspec] Review request: New
EFI_RISCV_BOOT_PROTOCOL

On 1/11/22 07:02, Sunil V L wrote:

On Tue, Jan 11, 2022 at 02:11:40AM +0000, Chang, Abner (HPS

SW/FW

Technologist) wrote:

-----Original Message-----
From: Heinrich Schuchardt

<heinrich.schuchardt@...>

Sent: Tuesday, January 11, 2022 9:20 AM
To: Chang, Abner (HPS SW/FW Technologist)

<abner.chang@...>

Cc: tech-unixplatformspec@...; Anup Patel
<apatel@...>; Atish Patra

<atishp@...>;

Jessica

Clarke <jrtc27@...>; Sunil V L

<sunilvl@...>

Subject: Re: Review request: New

EFI_RISCV_BOOT_PROTOCOL

On 1/11/22 02:07, Chang, Abner (HPS SW/FW Technologist)

wrote:

Hi Sunil,
Instead of having a spec for EFI_RISCV_BOOT_PROTOCOL

specifically, I

suggest to have a RISC-V EFI Protocols Specification. This spec

accommodates

EFI_RISCV_BOOT_PROTOCOL, the future EFI protocols for RISC-

V

platform,

and those we had implemented in edk2.

Which protocols in EDK II do you refer to?

"git grep -n RISC edk2/ | grep PRO" yields no result.

Oops... RiscVEdk2Sbi was implemented as library for now and

the plan is

to rap it as PPI/protocol, bad memory.

Even if there are no other RISC-V protocols today, Abner's

suggestion

will allow us to add them in future to the same document.

Once we have agreed on the EFI_RISCV_BOOT_PROTOCOL we

should

create

an
issue in bugzilla.tianocore.org and create a Mantis entry to get it
merged into the UEFI specification.

I don't think this would be accepted by UEFI forum. This is RISC-V

specific

protocol however, UEFI protocol is the abstract interface for

platform and

architecture. Unless you can come out a abstract interface that can
accommodate different processor/platform architectures (if they

also need

this).

We don't really need to merge the entire protocol to the UEFI

spec. We

need to maintain this within RISC-V organization like other RISC-V

specs

and add as a requirement in the platform spec. We can probably

add a

link under uefi.org/uefi and provide a reference in section 2.3.7.1.
UEFI allows us to do like this (ex: TCG2 protocols) and it may be

better

since we do not need to update the UEFI spec for any new

protocols

specific to RISC-V in future.

What do you think? Do you see any issue with this approach?

The TCG2 protocol is only a UEFI extension (see UEFI spec 2.9, p.68)

and

not required to claim UEFI compatibility.

If you put a protocol into the UEFI specification, you can be sure that
EDK II will implement it. And not firmware can claim to be UEFI
compliant without it.

To spec out something in either UEFI or RISC-V specific spec is actually

the same to RISC-V edk2 port IMO, if those are the mandatory protocols.

Edk2 RISC-V port should compliant with the firmware spec defined by

either specs, unless the spec says the protocol is specifically to uboot but it is
optional for other firmware solutions.

I think it would be better to enforce the mandatory requirement
explicitly in the UEFI spec. The actual content of the protocol can be
hosted under RISC-V.

Hi All,
I think I have addressed your comments. Please take a look at
https://github.com/riscv-non-isa/riscv-

uefi/releases/download/0.2/EFI_RISCV_PROTOCOL-spec.pdf.

If you think it is fine, I plan to get it reviewed once with Ard and
linux-riscv also where this solution was proposed originally.

We may not be able to add to mandatory UEFI section 2.6.1 but we can
try adding to 2.6.2 and mandate it via platform spec like we do for
PCI protocol.

Sounds good. One minor comment:

"While there can be a solution using /chosen node in DT based systems
to pass this information, a simple and common interface across DT and
ACPI platforms is desired on UEFI platforms to retrieve such
information."

The following statement should be improved to indicate that /chosen
node is an existing solution. However, it will not work for ACPI.
EFI_RISCV_BOOT_PROTOCOL should be the preferred over /chosen node
option for both DT/ACPI platforms.

Thanks. Updated as per your suggestion.
https://github.com/riscv-non-isa/riscv-
uefi/releases/download/0.3/EFI_RISCV_PROTOCOL-spec.pdf

I will work with you, Heinrich and Abner to get an codefirst ECR to
USWG.

We still need ECR?
The "codefirst" is to have the implementation first then submit the ECR for the new UEFI protocol.
However, we are not going to propose any protocols to UEFI spec. Even don't need to add a sentence for the external reference to this new document. To add the requirement in the platform spec is the perfect match IMO.

Hi Abner,
We need to add this requirement in the platform spec for sure. I will
send the patch once this is frozen.

But I think we also need to update the UEFI section 2.3.7.1 since it
already talks about the DT node, correct?

In addition, we can try adding this to 2.6.2 like other optional
protocols. I am not very sure whether USWG will agree for this. But
at the minimum if 2.3.7.1 can be updated.

Thanks
Sunil

Abner

Atish, should this be added to EBBR also?

Yeah. RISC-V Multiprocessor Startup Protocol should be updated.
EFI_RISCV_BOOT_PROTOCOL should be preferred first. In absence of this,
firmware must
provide the /chosen hartid for the DT based platforms.

I guess you don't need to update EBBR right away. Once this is
accepted in the UEFI forum, EBBR can be updated.

Sure.

Thanks
Sunil

Thanks
Sunil

Regards,
Abner

I would prefer if every UEFI protocol that is absolutely essential for
booting were required by the UEFI specification. If the details are
maintained inside the UEFI specification or outside, does not matter

to me.

Best regards

Heirnich

Thanks
Sunil

Regards,
Abner

Best regards

Heinrich

Thanks
Abner

-----Original Message-----
From: Heinrich Schuchardt

<heinrich.schuchardt@...>

Sent: Tuesday, January 11, 2022 1:28 AM
To: Sunil V L <sunilvl@...>
Cc: tech-unixplatformspec@...; Chang, Abner

(HPS SW/FW

Technologist) <abner.chang@...>; Anup Patel
<apatel@...>; Atish Patra

<atishp@...>;

Jessica

Clarke <jrtc27@...>
Subject: Re: Review request: New

EFI_RISCV_BOOT_PROTOCOL

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