[edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules


Dandan Bi <dandan.bi@...>
 

Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler/.../ StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code clear and easy to maintain, 2) make platform flexible to choose any handler library they need, and it also can reduce image size since the unused handlers can be excluded.
If you have any concern or comments for this separation, please let me know.

We plan to add new separated NULL class library MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo to cover the new NULL class library to make sure this change doesn't impact any platform.
After this separation, StatusCodeHandler module usage will like below, and it's also very flexible for platform to cover more handler libraries to meet their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf
...
}


Thanks,
Dandan


Laszlo Ersek
 

On 06/18/20 09:01, Dandan Bi wrote:
Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler/.../ StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code clear and easy to maintain, 2) make platform flexible to choose any handler library they need, and it also can reduce image size since the unused handlers can be excluded.
If you have any concern or comments for this separation, please let me know.

We plan to add new separated NULL class library MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo to cover the new NULL class library to make sure this change doesn't impact any platform.
After this separation, StatusCodeHandler module usage will like below, and it's also very flexible for platform to cover more handler libraries to meet their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf
...
}
So I assume you're going to remove PcdStatusCodeUseSerial and
PcdStatusCodeUseMemory, and when converting the existent platforms, the
new NULL class resolutions in the DSC files will reflect the specific
PCD values used in those DSC files until then. Is that right?

I'm OK with it.

Thanks
Laszlo


Brian J. Johnson
 

On 6/18/20 2:01 AM, Dandan Bi wrote:

Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816 <https://bugzilla.tianocore.org/show_bug.cgi?id=2816>

We plan to separate two kinds of NULL class libraries for Memory and serial handlers from *MdeModulePkg/Universal/StatusCodeHandler/…/ StatusCodeHandlerPei/RuntimeDxe/Smm* modules.

The benefit we want to gain from this separation is to 1) make the code clear and easy to maintain, 2) make platform flexible to choose any handler library they need, and it also can reduce image size since the unused handlers can be excluded.

If you have any concern or comments for this separation, please let me know.

We plan to add new separated NULL class library *MemoryStausCodeHandlerLib *and*SerialStatusCodeHandlerLib *with different phase implementation into *MdeModulePkg\Library\* directory.

The main tree structure may like below:

MdeModulePkg\Library

|------*MemoryStausCodeHandlerLib*

|------|------ PeiMemoryStausCodeHandlerLib.inf

|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf

|------|------ SmmMemoryStausCodeHandlerLib.inf

|------*SerialStatusCodeHandlerLib*

|------|------ PeiSerialStatusCodeHandlerLib.inf

|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf

|------|------ SmmSerialStatusCodeHandlerLib.inf

**

**

We will update existing platform use cases in edk2 and edk2-platform repo to cover the new NULL class library to make sure this change doesn’t impact any platform.

After this separation, StatusCodeHandler module usage will like below, and it’s also very flexible for platform to cover more handler libraries to meet their requirements.

MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf {

  <LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf

    …

}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf {

  <LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf

    …

}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf {

  <LibraryClasses>

 NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf

    …

}

Thanks,

Dandan
Dandan,

We'll have a lot of layers of indirection....  The ReportStatusCodeRouter modules will call one or more StatusCodeHandlerModules, and the standard StatusCodeHandler modules will call multiple StatusCodeHandlerLib libraries.

How about adding StatusCodeHandlerLib support directly to the ReportStatusCodeRouter modules?  Then platforms could omit the StatusCodeHandler modules if they're only using the open-source code.  That sounds like less overhead since fewer modules would be needed.

Thanks,

--

*Brian J. Johnson
*Enterprise X86 Lab

Hewlett Packard Enterprise

*hpe.com* <3D"hpe.com">


Andrew Fish <afish@...>
 

On Jun 19, 2020, at 10:29 AM, Brian J. Johnson <brian.johnson@...> wrote:

On 6/18/20 2:01 AM, Dandan Bi wrote:
Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial handlers fromMdeModulePkg/Universal/StatusCodeHandler/…/ StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code clear and easy to maintain, 2) make platform flexible to choose any handler library they need, and it also can reduce image size since the unused handlers can be excluded.
If you have any concern or comments for this separation, please let me know.

We plan to add new separated NULL class library MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo to cover the new NULL class library to make sure this change doesn’t impact any platform.
After this separation, StatusCodeHandler module usage will like below, and it’s also very flexible for platform to cover more handler libraries to meet their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf

}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf

}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf

}


Thanks,
Dandan
Dandan,

We'll have a lot of layers of indirection.... The ReportStatusCodeRouter modules will call one or more StatusCodeHandlerModules, and the standard StatusCodeHandler modules will call multiple StatusCodeHandlerLib libraries.

How about adding StatusCodeHandlerLib support directly to the ReportStatusCodeRouter modules? Then platforms could omit the StatusCodeHandler modules if they're only using the open-source code. That sounds like less overhead since fewer modules would be needed.

I think the need to execute from ROM makes this tricky.

It looks to me that it is easy to move from PCD to libs for the StatusCodeHandler since registration is basically `RscHandlerPpi->Register (SerialStatusCodeReportWorker);`. The issue I see is the ReportStatusCodeRouter publishes RscHandlerPpi after the PEIMs constructor has been called and if the PEIM. Given globals don’t work when running from ROM you would have to do something like publish a HOB in the library constructor and then have the GenericStatusCodePeiEntry() walk the HOBs and install the handlers. So I guess it is a little easier than I 1st thought when I started writing this mail, but it would require a new public API.

Thanks,

Andrew Fish
Thanks,

--
Brian J. Johnson
Enterprise X86 Lab

Hewlett Packard Enterprise

hpe.com <x-msg://64/3D%22hpe.com%22>


Dong, Eric <eric.dong@...>
 

From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Brian J. Johnson
Sent: Saturday, June 20, 2020 1:29 AM
To: devel@edk2.groups.io; Bi, Dandan <dandan.bi@...>; rfc@edk2.groups.io
Cc: Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>; Wang, Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>; Tan, Ming <ming.tan@...>
Subject: Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules

On 6/18/20 2:01 AM, Dandan Bi wrote:
Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler/.../ StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code clear and easy to maintain, 2) make platform flexible to choose any handler library they need, and it also can reduce image size since the unused handlers can be excluded.
If you have any concern or comments for this separation, please let me know.

We plan to add new separated NULL class library MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo to cover the new NULL class library to make sure this change doesn't impact any platform.
After this separation, StatusCodeHandler module usage will like below, and it's also very flexible for platform to cover more handler libraries to meet their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf
...
}


Thanks,
Dandan



Dandan,

We'll have a lot of layers of indirection.... The ReportStatusCodeRouter modules will call one or more StatusCodeHandlerModules, and the standard StatusCodeHandler modules will call multiple StatusCodeHandlerLib libraries.

How about adding StatusCodeHandlerLib support directly to the ReportStatusCodeRouter modules? Then platforms could omit the StatusCodeHandler modules if they're only using the open-source code. That sounds like less overhead since fewer modules would be needed



Hi Brain,

You are right. Current design truly has a lot of layers. The ReportStatusCodeRouter module provides the register logic and maintain the registered status code handlers. Now the platform may have more than one of drivers used to register the status code handler. This RFC used to resolve the platform has more than one status code handler drivers' issue. We expect the platform only need one wrapper driver in MdeModulePkg to let the status code handler library to register its handler on it.

Thanks,

Eric



Thanks,
--

Brian J. Johnson
Enterprise X86 Lab

Hewlett Packard Enterprise

hpe.com<3D%22hpe.com%22>


Dandan Bi <dandan.bi@...>
 

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Laszlo
Ersek
Sent: Friday, June 19, 2020 8:48 PM
To: rfc@edk2.groups.io; Bi, Dandan <dandan.bi@...>;
devel@edk2.groups.io
Cc: Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>; Wang,
Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>; Tan,
Ming <ming.tan@...>
Subject: Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler:
Separate NULL class libraries for Memory and serial handlers from
MdeModulePkg/Universal/StatusCodeHandler modules

On 06/18/20 09:01, Dandan Bi wrote:
Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial
handlers from MdeModulePkg/Universal/StatusCodeHandler/.../
StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code
clear and easy to maintain, 2) make platform flexible to choose any handler
library they need, and it also can reduce image size since the unused
handlers can be excluded.
If you have any concern or comments for this separation, please let me
know.

We plan to add new separated NULL class library
MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different
phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo
to cover the new NULL class library to make sure this change doesn't impact
any platform.
After this separation, StatusCodeHandler module usage will like below, and
it's also very flexible for platform to cover more handler libraries to meet
their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.in
f {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemorySt
ausCode
NULL|HandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusC
o
NULL|deHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHan
dlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeM
emorySt
NULL|ausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSeri
alS
NULL|tatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSm
m.inf {
<LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemory
StausCode
HandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatus
Co
NULL|deHandlerLib.inf
...
}
So I assume you're going to remove PcdStatusCodeUseSerial and
PcdStatusCodeUseMemory, and when converting the existent platforms,
the new NULL class resolutions in the DSC files will reflect the specific PCD
values used in those DSC files until then. Is that right?
Thanks for pointing out the PCD part which I miss in this RFC.
This commit https://github.com/tianocore/edk2/commit/45bc28172fbf38ac21e2592c07189b55f57695e3 have updated PcdStatusCodeUseSerial and PcdStatusCodeUseMemory type.
We plan to keep PcdStatusCodeUseSerial and PcdStatusCodeUseMemory. Through NULL class resolutions in the DSC can make the code handler code included or not, then we still can control handler enable/disable through the PCD dynamically if the handler is included.
What do you think of this?


Thanks,
Dandan
I'm OK with it.

Thanks
Laszlo



Dandan Bi <dandan.bi@...>
 

Hi Brian,

Personally, I prefer to add the NULL class Library to StatusCodeHandler modules.

1. I think we should make the functionality of each module clear and separated. It may also be why we added ReportStatusCodeRouter and StatusCodeHandler modules in edk2 repo before.

ReportStatusCodeRouter modules are responsible for producing Status Code Protocol/PPI and Report Status Code Handler Protocol/PPI, and StatusCodeHandler modules are responsible for producing handlers (Handlers can be provided by NULL class Libraries in this RFC).

So, that’s why I don’t want to add the NULL class Library to ReportStatusCodeRouter modules directly, which change the functionality scope of existing modules.



1. I agree that we have a lot of layers of indirection now, but what we may gain is the good modularity. And you also mentioned that one or more StatusCodeHandler Modules may be used. We also want to achieve that only the StatusCodeHandler modules in MdeModulePkg can be used after this separation, platform can only add its own handler Libs to meet its requirement.



1. As Andrew mentioned below, if add the libraries to ReportStatusCodeRouter, there will be some issue we need to fix, which seems also make the code logic a little tricky to me.



Thanks,
Dandan
From: Andrew Fish <afish@...>
Sent: Saturday, June 20, 2020 2:04 AM
To: edk2-devel-groups-io <devel@edk2.groups.io>; brian.johnson@...
Cc: Bi, Dandan <dandan.bi@...>; rfc@edk2.groups.io; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>; Wang, Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>; Tan, Ming <ming.tan@...>
Subject: Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules




On Jun 19, 2020, at 10:29 AM, Brian J. Johnson <brian.johnson@...<mailto:brian.johnson@...>> wrote:

On 6/18/20 2:01 AM, Dandan Bi wrote:
Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial handlers fromMdeModulePkg/Universal/StatusCodeHandler/…/ StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code clear and easy to maintain, 2) make platform flexible to choose any handler library they need, and it also can reduce image size since the unused handlers can be excluded.
If you have any concern or comments for this separation, please let me know.

We plan to add new separated NULL class library MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo to cover the new NULL class library to make sure this change doesn’t impact any platform.
After this separation, StatusCodeHandler module usage will like below, and it’s also very flexible for platform to cover more handler libraries to meet their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf

}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf

}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf

}


Thanks,
Dandan

Dandan,
We'll have a lot of layers of indirection.... The ReportStatusCodeRouter modules will call one or more StatusCodeHandlerModules, and the standard StatusCodeHandler modules will call multiple StatusCodeHandlerLib libraries.
How about adding StatusCodeHandlerLib support directly to the ReportStatusCodeRouter modules? Then platforms could omit the StatusCodeHandler modules if they're only using the open-source code. That sounds like less overhead since fewer modules would be needed.


I think the need to execute from ROM makes this tricky.

It looks to me that it is easy to move from PCD to libs for the StatusCodeHandler since registration is basically `RscHandlerPpi->Register (SerialStatusCodeReportWorker);`. The issue I see is the ReportStatusCodeRouter publishes RscHandlerPpi after the PEIMs constructor has been called and if the PEIM. Given globals don’t work when running from ROM you would have to do something like publish a HOB in the library constructor and then have the GenericStatusCodePeiEntry() walk the HOBs and install the handlers. So I guess it is a little easier than I 1st thought when I started writing this mail, but it would require a new public API.

Thanks,

Andrew Fish

Thanks,
--

Brian J. Johnson
Enterprise X86 Lab

Hewlett Packard Enterprise

hpe.com<x-msg://64/3D%22hpe.com%22>


Laszlo Ersek
 

On 06/22/20 06:57, Bi, Dandan wrote:
-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Laszlo
Ersek
Sent: Friday, June 19, 2020 8:48 PM
To: rfc@edk2.groups.io; Bi, Dandan <dandan.bi@...>;
devel@edk2.groups.io
Cc: Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>; Wang,
Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>; Tan,
Ming <ming.tan@...>
Subject: Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler:
Separate NULL class libraries for Memory and serial handlers from
MdeModulePkg/Universal/StatusCodeHandler modules

On 06/18/20 09:01, Dandan Bi wrote:
Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial
handlers from MdeModulePkg/Universal/StatusCodeHandler/.../
StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code
clear and easy to maintain, 2) make platform flexible to choose any handler
library they need, and it also can reduce image size since the unused
handlers can be excluded.
If you have any concern or comments for this separation, please let me
know.

We plan to add new separated NULL class library
MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different
phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo
to cover the new NULL class library to make sure this change doesn't impact
any platform.
After this separation, StatusCodeHandler module usage will like below, and
it's also very flexible for platform to cover more handler libraries to meet
their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.in
f {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemorySt
ausCode
NULL|HandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusC
o
NULL|deHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHan
dlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeM
emorySt
NULL|ausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSeri
alS
NULL|tatusCodeHandlerLib.inf
...
}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSm
m.inf {
<LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemory
StausCode
HandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatus
Co
NULL|deHandlerLib.inf
...
}
So I assume you're going to remove PcdStatusCodeUseSerial and
PcdStatusCodeUseMemory, and when converting the existent platforms,
the new NULL class resolutions in the DSC files will reflect the specific PCD
values used in those DSC files until then. Is that right?
Thanks for pointing out the PCD part which I miss in this RFC.
This commit https://github.com/tianocore/edk2/commit/45bc28172fbf38ac21e2592c07189b55f57695e3 have updated PcdStatusCodeUseSerial and PcdStatusCodeUseMemory type.
We plan to keep PcdStatusCodeUseSerial and PcdStatusCodeUseMemory. Through NULL class resolutions in the DSC can make the code handler code included or not, then we still can control handler enable/disable through the PCD dynamically if the handler is included.
What do you think of this?
Hm... OK.

Thanks
Laszlo


Brian J. Johnson
 

Dandan,

The Status Code Protocol/PPI is the high-level interface which is being implemented.  The ReportStatusCodeRouter module implements this in terms of the ReportStatusCodeHandler Protocol/PPI.  That allows multiple ReportStatusCodeHandler modules to be used at once, so they can each react to different types of status codes, or report them through multiple channels.  That sort of multiplexing seems like a useful feature.

Now we're considering adding a mechanism which allows registering status code handlers via NULL libraries, rather than via the protocol/PPI.  That sounds like exactly what ReportStatusCodeRouter is intended for.  It wouldn't really change its scope, it would just make it more flexible.  Adding this feature via a StatusCodeHandler module wouldn't improve modularity, it would just add complexity.  As an OEM, adding a custom handler would look the same to me either way:  I would have to add the NULL class library to a MdeModulePkg driver's entry in my .dsc file.  It doesn't matter to me whether it's the ReportStatusCodeRouter or StatusCodeHandler module.  And if I can do it in ReportStatusCodeRouter, then I don't need to include any StatusCodeHandler modules in the build at all.  That saves code space and reduces the number of modules in the APRIORI list, which are both good things.

ReportStatusCodeRouterPei already has to track registered handlers in PEI when running from ROM (it uses a HOB.)  Tracking handlers from NULL libraries wouldn't be any harder.  In fact, it looks like it could just export the Register() function to the NULL libraries, and they could call it in their constructors.

I think using NULL libraries for status code handlers is a great idea.  I'd just like to take that opportunity to reduce the complexity of the overall status code stack while we're at it.

Thanks,

*Brian J. Johnson
*Enterprise X86 Lab

Hewlett Packard Enterprise

------------------------------------------------------------------------
*From:* Bi, Dandan [mailto:dandan.bi@...]
*Sent:* Monday, June 22, 2020, 2:27 AM
*To:* Andrew Fish <afish@...>, edk2-devel-groups-io <devel@edk2.groups.io>, brian.johnson@... <brian.johnson@...>
*Cc:* rfc@edk2.groups.io <rfc@edk2.groups.io>, Dong, Eric <eric.dong@...>, Ni, Ray <ray.ni@...>, Wang, Jian J <jian.j.wang@...>, Wu, Hao A <hao.a.wu@...>, Tan, Ming <ming.tan@...>, Laszlo Ersek <lersek@...>, Bi, Dandan <dandan.bi@...>
*Subject:* [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules

Hi Brian,

Personally, I prefer to add the NULL class Library to StatusCodeHandler modules.

1. I think we should make the functionality of each module clear and
separated. It may also be why we added ReportStatusCodeRouter and
StatusCodeHandler modules in edk2 repo before.

ReportStatusCodeRouter modules are responsible for producing Status Code Protocol/PPI and Report Status Code Handler Protocol/PPI, and StatusCodeHandler modules are responsible for producing handlers (Handlers can be provided by NULL class Libraries in this RFC).

 So, that’s why I don’t want to add the NULL class Library to ReportStatusCodeRouter modules directly, which change the functionality scope of existing modules.

2. I agree that we have a lot of layers of indirection now, but what
we may gain is the good modularity. And you also mentioned that
one or more StatusCodeHandler Modules may be used. We also want to
achieve that only the StatusCodeHandler modules in MdeModulePkg
can be used after this separation, platform can only add its own
handler Libs to meet its requirement.

3. As Andrew mentioned below, if add the libraries to
ReportStatusCodeRouter, there will be some issue we need to fix,
which seems also make the code logic a little tricky to me.

Thanks,

Dandan

*From:* Andrew Fish <afish@...>
*Sent:* Saturday, June 20, 2020 2:04 AM
*To:* edk2-devel-groups-io <devel@edk2.groups.io>; brian.johnson@...
*Cc:* Bi, Dandan <dandan.bi@...>; rfc@edk2.groups.io; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>; Wang, Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>; Tan, Ming <ming.tan@...>
*Subject:* Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules



On Jun 19, 2020, at 10:29 AM, Brian J. Johnson
<brian.johnson@... <mailto:brian.johnson@...>wrote:

On 6/18/20 2:01 AM, Dandan Bi wrote:

Hi All,

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2816
<https://bugzilla.tianocore.org/show_bug.cgi?id=2816>

We plan to separate two kinds of NULL class libraries for
Memory and serial handlers
from*MdeModulePkg/Universal/StatusCodeHandler/…/
StatusCodeHandlerPei/RuntimeDxe/Smm*modules.

The benefit we want to gain from this separation is to 1) make
the code clear and easy to maintain, 2) make platform flexible
to choose any handler library they need, and it also can
reduce image size since the unused handlers can be excluded.

If you have any concern or comments for this separation,
please let me know.

We plan to add new separated NULL class
library*MemoryStausCodeHandlerLib*and***SerialStatusCodeHandlerLib*with
different phase implementation
into*MdeModulePkg\Library\*directory.

The main tree structure may like below:

MdeModulePkg\Library

|------*MemoryStausCodeHandlerLib*

|------|------ PeiMemoryStausCodeHandlerLib.inf

|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf

|------|------ SmmMemoryStausCodeHandlerLib.inf

|------*SerialStatusCodeHandlerLib*

|------|------ PeiSerialStatusCodeHandlerLib.inf

|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf

|------|------ SmmSerialStatusCodeHandlerLib.inf

**

**

We will update existing platform use cases in edk2 and
edk2-platform repo to cover the new NULL class library to make
sure this change doesn’t impact any platform.

After this separation, StatusCodeHandler module usage will
like below, and it’s also very flexible for platform to cover
more handler libraries to meet their requirements.

MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf
{

<LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf



}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf
{

<LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf



}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf
{

<LibraryClasses>

 NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf



}

Thanks,

Dandan

Dandan,

We'll have a lot of layers of indirection....  The
ReportStatusCodeRouter modules will call one or more
StatusCodeHandlerModules, and the standard StatusCodeHandler
modules will call multiple StatusCodeHandlerLib libraries.

How about adding StatusCodeHandlerLib support directly to the
ReportStatusCodeRouter modules?  Then platforms could omit the
StatusCodeHandler modules if they're only using the open-source
code.  That sounds like less overhead since fewer modules would be
needed.

I think the need to execute from ROM makes this tricky.

It looks to me that it is easy to move from PCD to libs for the StatusCodeHandler since registration is basically `RscHandlerPpi->Register (SerialStatusCodeReportWorker);`. The issue I see is the ReportStatusCodeRouter publishes RscHandlerPpi after the PEIMs constructor has been called and if the PEIM. Given globals don’t work when running from ROM you would have to do something like publish a HOB in the library constructor and then have the GenericStatusCodePeiEntry() walk the HOBs and install the handlers. So I guess it is a little easier than I 1st thought when I started writing this mail, but it would require a new public API.

Thanks,

Andrew Fish

Thanks,

--

*Brian J. Johnson
*Enterprise X86 Lab

Hewlett Packard Enterprise

*hpe.com* <x-msg://64/3D%22hpe.com%22>

-


Dong, Eric <eric.dong@...>
 

Hi Brian,

In this new design, we still use register status code handler Protocol/Ppi to register the handler logic. We just want to change the StatusCodeHandler driver. We try to split the register logic to NULL library to make the code more modularity. We already created sample library in Edk2-Platforms repo https://github.com/tianocore/edk2-platforms/tree/master/Features/Intel/Debugging/PostCodeDebugFeaturePkg/Library/PostCodeStatusCodeHandlerLib. You can check this code to understand more about what we want to do.

Thanks,
Eric
From: Brian J. Johnson <brian.johnson@...>
Sent: Thursday, June 25, 2020 4:25 AM
To: Bi, Dandan <dandan.bi@...>; Andrew Fish <afish@...>; edk2-devel-groups-io <devel@edk2.groups.io>
Cc: rfc@edk2.groups.io; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>; Wang, Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>; Tan, Ming <ming.tan@...>; Laszlo Ersek <lersek@...>
Subject: Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules

Dandan,

The Status Code Protocol/PPI is the high-level interface which is being implemented. The ReportStatusCodeRouter module implements this in terms of the ReportStatusCodeHandler Protocol/PPI. That allows multiple ReportStatusCodeHandler modules to be used at once, so they can each react to different types of status codes, or report them through multiple channels. That sort of multiplexing seems like a useful feature.

Now we're considering adding a mechanism which allows registering status code handlers via NULL libraries, rather than via the protocol/PPI. That sounds like exactly what ReportStatusCodeRouter is intended for. It wouldn't really change its scope, it would just make it more flexible. Adding this feature via a StatusCodeHandler module wouldn't improve modularity, it would just add complexity. As an OEM, adding a custom handler would look the same to me either way: I would have to add the NULL class library to a MdeModulePkg driver's entry in my .dsc file. It doesn't matter to me whether it's the ReportStatusCodeRouter or StatusCodeHandler module. And if I can do it in ReportStatusCodeRouter, then I don't need to include any StatusCodeHandler modules in the build at all. That saves code space and reduces the number of modules in the APRIORI list, which are both good things.

ReportStatusCodeRouterPei already has to track registered handlers in PEI when running from ROM (it uses a HOB.) Tracking handlers from NULL libraries wouldn't be any harder. In fact, it looks like it could just export the Register() function to the NULL libraries, and they could call it in their constructors.

I think using NULL libraries for status code handlers is a great idea. I'd just like to take that opportunity to reduce the complexity of the overall status code stack while we're at it.

Thanks,

Brian J. Johnson
Enterprise X86 Lab

Hewlett Packard Enterprise

________________________________
From: Bi, Dandan [mailto:dandan.bi@...]
Sent: Monday, June 22, 2020, 2:27 AM
To: Andrew Fish <afish@...><mailto:afish@...>, edk2-devel-groups-io <devel@edk2.groups.io><mailto:devel@edk2.groups.io>, brian.johnson@...<mailto:brian.johnson@...> <brian.johnson@...><mailto:brian.johnson@...>
Cc: rfc@edk2.groups.io<mailto:rfc@edk2.groups.io> <rfc@edk2.groups.io><mailto:rfc@edk2.groups.io>, Dong, Eric <eric.dong@...><mailto:eric.dong@...>, Ni, Ray <ray.ni@...><mailto:ray.ni@...>, Wang, Jian J <jian.j.wang@...><mailto:jian.j.wang@...>, Wu, Hao A <hao.a.wu@...><mailto:hao.a.wu@...>, Tan, Ming <ming.tan@...><mailto:ming.tan@...>, Laszlo Ersek <lersek@...><mailto:lersek@...>, Bi, Dandan <dandan.bi@...><mailto:dandan.bi@...>
Subject: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules

Hi Brian,

Personally, I prefer to add the NULL class Library to StatusCodeHandler modules.

1. I think we should make the functionality of each module clear and separated. It may also be why we added ReportStatusCodeRouter and StatusCodeHandler modules in edk2 repo before.

ReportStatusCodeRouter modules are responsible for producing Status Code Protocol/PPI and Report Status Code Handler Protocol/PPI, and StatusCodeHandler modules are responsible for producing handlers (Handlers can be provided by NULL class Libraries in this RFC).

So, that’s why I don’t want to add the NULL class Library to ReportStatusCodeRouter modules directly, which change the functionality scope of existing modules.



1. I agree that we have a lot of layers of indirection now, but what we may gain is the good modularity. And you also mentioned that one or more StatusCodeHandler Modules may be used. We also want to achieve that only the StatusCodeHandler modules in MdeModulePkg can be used after this separation, platform can only add its own handler Libs to meet its requirement.



1. As Andrew mentioned below, if add the libraries to ReportStatusCodeRouter, there will be some issue we need to fix, which seems also make the code logic a little tricky to me.



Thanks,
Dandan
From: Andrew Fish <afish@...><mailto:afish@...>
Sent: Saturday, June 20, 2020 2:04 AM
To: edk2-devel-groups-io <devel@edk2.groups.io><mailto:devel@edk2.groups.io>; brian.johnson@...<mailto:brian.johnson@...>
Cc: Bi, Dandan <dandan.bi@...><mailto:dandan.bi@...>; rfc@edk2.groups.io<mailto:rfc@edk2.groups.io>; Dong, Eric <eric.dong@...><mailto:eric.dong@...>; Ni, Ray <ray.ni@...><mailto:ray.ni@...>; Wang, Jian J <jian.j.wang@...><mailto:jian.j.wang@...>; Wu, Hao A <hao.a.wu@...><mailto:hao.a.wu@...>; Tan, Ming <ming.tan@...><mailto:ming.tan@...>
Subject: Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules





On Jun 19, 2020, at 10:29 AM, Brian J. Johnson <brian.johnson@...<mailto:brian.johnson@...>wrote:

On 6/18/20 2:01 AM, Dandan Bi wrote:
Hi All,

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2816

We plan to separate two kinds of NULL class libraries for Memory and serial handlers fromMdeModulePkg/Universal/StatusCodeHandler/…/ StatusCodeHandlerPei/RuntimeDxe/Smm modules.
The benefit we want to gain from this separation is to 1) make the code clear and easy to maintain, 2) make platform flexible to choose any handler library they need, and it also can reduce image size since the unused handlers can be excluded.
If you have any concern or comments for this separation, please let me know.

We plan to add new separated NULL class library MemoryStausCodeHandlerLib and SerialStatusCodeHandlerLib with different phase implementation into MdeModulePkg\Library\ directory.
The main tree structure may like below:
MdeModulePkg\Library
|------MemoryStausCodeHandlerLib
|------|------ PeiMemoryStausCodeHandlerLib.inf
|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf
|------|------ SmmMemoryStausCodeHandlerLib.inf
|------SerialStatusCodeHandlerLib
|------|------ PeiSerialStatusCodeHandlerLib.inf
|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf
|------|------ SmmSerialStatusCodeHandlerLib.inf


We will update existing platform use cases in edk2 and edk2-platform repo to cover the new NULL class library to make sure this change doesn’t impact any platform.
After this separation, StatusCodeHandler module usage will like below, and it’s also very flexible for platform to cover more handler libraries to meet their requirements.
MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf

}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf

}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf {
<LibraryClasses>
NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf
NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf

}


Thanks,
Dandan

Dandan,
We'll have a lot of layers of indirection.... The ReportStatusCodeRouter modules will call one or more StatusCodeHandlerModules, and the standard StatusCodeHandler modules will call multiple StatusCodeHandlerLib libraries.
How about adding StatusCodeHandlerLib support directly to the ReportStatusCodeRouter modules? Then platforms could omit the StatusCodeHandler modules if they're only using the open-source code. That sounds like less overhead since fewer modules would be needed.


I think the need to execute from ROM makes this tricky.

It looks to me that it is easy to move from PCD to libs for the StatusCodeHandler since registration is basically `RscHandlerPpi->Register (SerialStatusCodeReportWorker);`. The issue I see is the ReportStatusCodeRouter publishes RscHandlerPpi after the PEIMs constructor has been called and if the PEIM. Given globals don’t work when running from ROM you would have to do something like publish a HOB in the library constructor and then have the GenericStatusCodePeiEntry() walk the HOBs and install the handlers. So I guess it is a little easier than I 1st thought when I started writing this mail, but it would require a new public API.

Thanks,

Andrew Fish


Thanks,
--

Brian J. Johnson
Enterprise X86 Lab

Hewlett Packard Enterprise

hpe.com<x-msg://64/3D%22hpe.com%22>



-


Brian J. Johnson
 

Thanks for the link.  I agree that this change will make the StatusCodeHandler driver more modular, and is a step in the right direction.

But I think it could go further, with almost no additional work, and simplify the overall Status Code mechanism, not just the StatusCodeHandler driver.  Currently, the StatusCodeHandler driver entry routines run some initialization code, register callbacks (eg. for ExitBootServices and SetVirtualAddressMap), and call the RscHandler PPI/Protocol to register the worker routines.  If I'm understanding the proposal correctly, all that code will be moved to the individual NULL libraries, since any particular library may or may not need any of it.  Then the StatusCodeHandler modules will be left with no code of their own at all:  they will only be wrappers for the NULL libraries. Their entry routines will do nothing except return EFI_SUCCESS! (1)

It seems strange and wasteful to keep around empty modules like this.  So I'm suggesting adding the NULL libraries to the StatusCodeRouter modules instead.  They would need to export the protocol/PPI routines to the NULL libraries via a header file, so they could call them directly instead of looking up the protocol/PPI.  But that's a minor change.  Then you could remove the empty StatusCodeHandler modules entirely.  The advantage would be that there would be fewer modules in the build, simplifying the .dsc and .fdf files slightly.  It would also reduce code size a bit by sharing common library routines, such as BaseLib, with the StatusCodeRouter modules.

If those don't seem like worthwhile advantages, that's OK with me.  I don't want to belabor the point, or impede progress.  If others are OK with the proposal as it stands, then I am too.

Thanks,

*Brian J. Johnson
*Enterprise X86 Lab

Hewlett Packard Enterprise


(1) The StatusCodeHandlerRuntimeDxe driver also handles PcdStatusCodeReplayIn as part of its entry code.  That code would probably have to stay in a separate module rather than being linked to StatusCodeRouter as a NULL library.  That way it could be dispatched after the ReportStatusCode protocol is available.

------------------------------------------------------------------------
*From:* Dong, Eric [mailto:eric.dong@...]
*Sent:* Thursday, June 25, 2020, 10:41 AM
*To:* Brian J. Johnson <brian.johnson@...>, Bi, Dandan <dandan.bi@...>, Andrew Fish <afish@...>, edk2-devel-groups-io <devel@edk2.groups.io>
*Cc:* rfc@edk2.groups.io <rfc@edk2.groups.io>, Ni, Ray <ray.ni@...>, Wang, Jian J <jian.j.wang@...>, Wu, Hao A <hao.a.wu@...>, Tan, Ming <ming.tan@...>, Laszlo Ersek <lersek@...>
*Subject:* [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules

Hi Brian,

In this new design, we still use register status code handler Protocol/Ppi to register the handler logic. We just want to change the StatusCodeHandler driver. We try to split the register logic to NULL library to make the code more modularity. We already created sample library in Edk2-Platforms repo https://github.com/tianocore/edk2-platforms/tree/master/Features/Intel/Debugging/PostCodeDebugFeaturePkg/Library/PostCodeStatusCodeHandlerLib. You can check this code to understand more about what we want to do.

Thanks,

Eric

*From:* Brian J. Johnson <brian.johnson@...>
*Sent:* Thursday, June 25, 2020 4:25 AM
*To:* Bi, Dandan <dandan.bi@...>; Andrew Fish <afish@...>; edk2-devel-groups-io <devel@edk2.groups.io>
*Cc:* rfc@edk2.groups.io; Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>; Wang, Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>; Tan, Ming <ming.tan@...>; Laszlo Ersek <lersek@...>
*Subject:* Re: [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules

Dandan,

The Status Code Protocol/PPI is the high-level interface which is being implemented.  The ReportStatusCodeRouter module implements this in terms of the ReportStatusCodeHandler Protocol/PPI.  That allows multiple ReportStatusCodeHandler modules to be used at once, so they can each react to different types of status codes, or report them through multiple channels.  That sort of multiplexing seems like a useful feature.

Now we're considering adding a mechanism which allows registering status code handlers via NULL libraries, rather than via the protocol/PPI. That sounds like exactly what ReportStatusCodeRouter is intended for.  It wouldn't really change its scope, it would just make it more flexible.  Adding this feature via a StatusCodeHandler module wouldn't improve modularity, it would just add complexity.  As an OEM, adding a custom handler would look the same to me either way:  I would have to add the NULL class library to a MdeModulePkg driver's entry in my .dsc file.  It doesn't matter to me whether it's the ReportStatusCodeRouter or StatusCodeHandler module.  And if I can do it in ReportStatusCodeRouter, then I don't need to include any StatusCodeHandler modules in the build at all.  That saves code space and reduces the number of modules in the APRIORI list, which are both good things.

ReportStatusCodeRouterPei already has to track registered handlers in PEI when running from ROM (it uses a HOB.)  Tracking handlers from NULL libraries wouldn't be any harder.  In fact, it looks like it could just export the Register() function to the NULL libraries, and they could call it in their constructors.

I think using NULL libraries for status code handlers is a great idea.  I'd just like to take that opportunity to reduce the complexity of the overall status code stack while we're at it.

Thanks,

*Brian J. Johnson
*Enterprise X86 Lab

Hewlett Packard Enterprise

------------------------------------------------------------------------

*From:* Bi, Dandan [mailto:dandan.bi@...]

*Sent:* Monday, June 22, 2020, 2:27 AM

*To:* Andrew Fish <afish@...> <mailto:afish@...>, edk2-devel-groups-io <devel@edk2.groups.io> <mailto:devel@edk2.groups.io>, brian.johnson@... <mailto:brian.johnson@...> <brian.johnson@...> <mailto:brian.johnson@...>

*Cc:* rfc@edk2.groups.io <mailto:rfc@edk2.groups.io> <rfc@edk2.groups.io> <mailto:rfc@edk2.groups.io>, Dong, Eric <eric.dong@...> <mailto:eric.dong@...>, Ni, Ray <ray.ni@...> <mailto:ray.ni@...>, Wang, Jian J <jian.j.wang@...> <mailto:jian.j.wang@...>, Wu, Hao A <hao.a.wu@...> <mailto:hao.a.wu@...>, Tan, Ming <ming.tan@...> <mailto:ming.tan@...>, Laszlo Ersek <lersek@...> <mailto:lersek@...>, Bi, Dandan <dandan.bi@...> <mailto:dandan.bi@...>

*Subject:* [edk2-devel] [edk2-rfc] MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for Memory and serial handlers from MdeModulePkg/Universal/StatusCodeHandler modules

Hi Brian,

Personally, I prefer to add the NULL class Library to
StatusCodeHandler modules.

1. I think we should make the functionality of each module clear
and separated. It may also be why we added
ReportStatusCodeRouter and StatusCodeHandler modules in edk2
repo before.

ReportStatusCodeRouter modules are responsible for producing
Status Code Protocol/PPI and Report Status Code Handler
Protocol/PPI, and StatusCodeHandler modules are responsible for
producing handlers (Handlers can be provided by NULL class
Libraries in this RFC).

 So, that’s why I don’t want to add the NULL class Library to
ReportStatusCodeRouter modules directly, which change the
functionality scope of existing modules.

2. I agree that we have a lot of layers of indirection now, but
what we may gain is the good modularity. And you also
mentioned that one or more StatusCodeHandler Modules may be
used. We also want to achieve that only the StatusCodeHandler
modules in MdeModulePkg can be used after this separation,
platform can only add its own handler Libs to meet its
requirement.

3. As Andrew mentioned below, if add the libraries to
ReportStatusCodeRouter, there will be some issue we need to
fix, which seems also make the code logic a little tricky to me.

Thanks,

Dandan

*From:* Andrew Fish <afish@...> <mailto:afish@...>
*Sent:* Saturday, June 20, 2020 2:04 AM
*To:* edk2-devel-groups-io <devel@edk2.groups.io>
<mailto:devel@edk2.groups.io>; brian.johnson@...
<mailto:brian.johnson@...>
*Cc:* Bi, Dandan <dandan.bi@...>
<mailto:dandan.bi@...>; rfc@edk2.groups.io
<mailto:rfc@edk2.groups.io>; Dong, Eric <eric.dong@...>
<mailto:eric.dong@...>; Ni, Ray <ray.ni@...>
<mailto:ray.ni@...>; Wang, Jian J <jian.j.wang@...>
<mailto:jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>
<mailto:hao.a.wu@...>; Tan, Ming <ming.tan@...>
<mailto:ming.tan@...>
*Subject:* Re: [edk2-devel] [edk2-rfc]
MdeModulePkg/StatusCodeHandler: Separate NULL class libraries for
Memory and serial handlers from
MdeModulePkg/Universal/StatusCodeHandler modules




On Jun 19, 2020, at 10:29 AM, Brian J. Johnson
<brian.johnson@... <mailto:brian.johnson@...>wrote:

On 6/18/20 2:01 AM, Dandan Bi wrote:

Hi All,

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2816
<https://bugzilla.tianocore.org/show_bug.cgi?id=2816>

We plan to separate two kinds of NULL class libraries for
Memory and serial handlers
from*MdeModulePkg/Universal/StatusCodeHandler/…/
StatusCodeHandlerPei/RuntimeDxe/Smm*modules.

The benefit we want to gain from this separation is to 1)
make the code clear and easy to maintain, 2) make platform
flexible to choose any handler library they need, and it
also can reduce image size since the unused handlers can
be excluded.

If you have any concern or comments for this separation,
please let me know.

We plan to add new separated NULL class
library*MemoryStausCodeHandlerLib*and***SerialStatusCodeHandlerLib*with
different phase implementation
into*MdeModulePkg\Library\*directory.

The main tree structure may like below:

MdeModulePkg\Library

|------*MemoryStausCodeHandlerLib*

|------|------ PeiMemoryStausCodeHandlerLib.inf

|------|------ RuntimeDxeMemoryStatusCodeHandlerLib.inf

|------|------ SmmMemoryStausCodeHandlerLib.inf

|------*SerialStatusCodeHandlerLib*

|------|------ PeiSerialStatusCodeHandlerLib.inf

|------|------ RuntimeDxeSerialStatusCodeHandlerLib.inf

|------|------ SmmSerialStatusCodeHandlerLib.inf

**

**

We will update existing platform use cases in edk2 and
edk2-platform repo to cover the new NULL class library to
make sure this change doesn’t impact any platform.

After this separation, StatusCodeHandler module usage will
like below, and it’s also very flexible for platform to
cover more handler libraries to meet their requirements.

MdeModulePkg/Universal/StatusCodeHandler/Pei/StatusCodeHandlerPei.inf
{

<LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/PeiMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/PeiSerialStatusCodeHandlerLib.inf



}

MdeModulePkg/Universal/StatusCodeHandler/RuntimeDxe/StatusCodeHandlerRuntimeDxe.inf
{

<LibraryClasses>

NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/RuntimeDxeMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/RuntimeDxeSerialStatusCodeHandlerLib.inf



}

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerSmm.inf
{

<LibraryClasses>

 NULL|MdeModulePkg/Library/MemoryStausCodeHandlerLib/SmmMemoryStausCodeHandlerLib.inf

NULL|MdeModulePkg/Library/SerialStatusCodeHandlerLib/SmmSerialStatusCodeHandlerLib.inf



}

Thanks,

Dandan

Dandan,

We'll have a lot of layers of indirection....  The
ReportStatusCodeRouter modules will call one or more
StatusCodeHandlerModules, and the standard StatusCodeHandler
modules will call multiple StatusCodeHandlerLib libraries.

How about adding StatusCodeHandlerLib support directly to the
ReportStatusCodeRouter modules? Then platforms could omit the
StatusCodeHandler modules if they're only using the
open-source code.  That sounds like less overhead since fewer
modules would be needed.

I think the need to execute from ROM makes this tricky.

It looks to me that it is easy to move from PCD to libs for the
StatusCodeHandler since registration is basically
`RscHandlerPpi->Register (SerialStatusCodeReportWorker);`. The
issue I see is the ReportStatusCodeRouter publishes RscHandlerPpi
after the PEIMs constructor has been called and if the PEIM. Given
globals don’t work when running from ROM you would have to do
something like publish a HOB in the library constructor and then
have the GenericStatusCodePeiEntry() walk the HOBs and install the
handlers. So I guess it is a little easier than I 1st thought when
I started writing this mail, but it would require a new public API.

Thanks,

Andrew Fish


Thanks,

--

*Brian J. Johnson
*Enterprise X86 Lab

Hewlett Packard Enterprise

*hpe.com* <x-msg://64/3D%22hpe.com%22>


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