Re: [edk2-devel] [edk2-platforms][PATCH v3 0/4] Implement S3 resume

["Isaac Oram" <isaac.w.oram@intel.com>]

Pushed as ee8d078e39..4d99e03828

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Isaac Oram
Sent: Tuesday, October 11, 2022 6:31 PM
To: Benjamin Doron <benjamin.doron00@gmail.com>; devel@edk2.groups.io
Cc: Chaganty, Rangasai V <rangasai.v.chaganty@intel.com>; Desimone, Nathaniel L <nathaniel.l.desimone@intel.com>; Sinha, Ankit <ankit.sinha@intel.com>; Chiu, Chasel <chasel.chiu@intel.com>; Gao, Liming <gaoliming@byosoft.com.cn>; Dong, Eric <eric.dong@intel.com>; Soller, Jeremy <jeremy@system76.com>
Subject: Re: [edk2-devel] [edk2-platforms][PATCH v3 0/4] Implement S3 resume

Series Reviewed-by: Isaac Oram <Isaac.w.oram@intel.com>

-----Original Message-----
From: Benjamin Doron <benjamin.doron00@gmail.com> 
Sent: Monday, September 12, 2022 10:13 AM
To: devel@edk2.groups.io
Cc: Chaganty, Rangasai V <rangasai.v.chaganty@intel.com>; Oram, Isaac W <isaac.w.oram@intel.com>; Desimone, Nathaniel L <nathaniel.l.desimone@intel.com>; Sinha, Ankit <ankit.sinha@intel.com>; Chiu, Chasel <chasel.chiu@intel.com>; Gao, Liming <gaoliming@byosoft.com.cn>; Dong, Eric <eric.dong@intel.com>; Soller, Jeremy <jeremy@system76.com>
Subject: [edk2-platforms][PATCH v3 0/4] Implement S3 resume

MinPlatform is an open-source EDK2 firmware project that can boot some mainstream boards. However, it lacked working support for S3 resume, an important feature for mobile platforms, which means that its applicability as-is to mainstream use is limited. Therefore, I have now implemented working S3 resume support on MinPlatform. This patch series comprises a majority of one of my work products for GSoC 2022.

The BootScript-related modules are EDK2 open-source and fairly straightforward to include. However, the partial dependency PiSmmCommunicationPei (for signalling SMM) creates a dependency on both the SmmAccess and SmmControl PPIs, so these are implemented here as libraries, ported from the DXE drivers. As the register definitions are generic, one library shim is implemented for compatibility, so the library can be generic too. SmmAccess shall be required regardless of SMM signalling, for the LockBox.

Like all boots, S3 resume will require working DRAM. To my understanding, we do not need to parse the memory map HOBs again, so some memory is allocated in DXE phase (to reserve it), the address stashed in a variable and consumed on S3 resume flows. Some optimisation can be performed here, regarding how much is necessary.
Stashing in a variable is imperfect, but the details must be available without DRAM. As the FSP HOBs are published later, SmmAccess cannot be used to retrieve from the LockBox.

Per my suspicions, notes from my mentors, Nate and Ankit, and the coreboot code, the PAMs are opened for access to the AP wake vectors.
Presently, all are opened, more research can be performed here.

As noted, either FSP or PiSmmCpuDxeSmm can apply boot CPU structures (GDT, IDT, MTRRs, etc). Per my research and findings by my mentors, the closed-source module CpuInitDxe would be required, so this implementation includes CpuS3DataDxe and open-source code will perform this task instead.

Unfortunately, board-specific code has some tasks to perform too. I've implemented these for Kabylake, the platform I can test. This includes detecting the boot mode, policy (memory overwrite is contraindicated, do not pass a VBT so FSP does not initialise graphics again) and ensuring a special provision, if desired, for debugging BootScriptExecutorDxe.

One major bug that blocked progress was simply specific to debugging.
DebugLibReportStatusCode should not be used for that module, because RSC has uninstalled the serial port handler at end-of-BS. Furthermore, it's obvious that the boot services are now unavailable. So, DebugLibSerialPort should be used. As an aside, due to AutoGen ordering, gBS cannot be used in SerialPortInitialize(). What really makes this module a unique case is the fact that it's behaviour is very like runtime drivers. For the integrity of the platform's security, the module is copied to the LockBox at DxeSmmReadyToLock. This caused one major bug that was blocking progress: libraries cannot attempt to modify globals (the data section) with end-of-BS events; they will never reach the true copy. So, rather than using flags to control code flow, it must be coded this way instead. For instance, there is now a special variant of I2cHdmiDebugSerialPortLib that does not use gBS in SerialPortWrite().

Previous revisions of this patch-set tested on my Aspire VN7-572G (Skylake). It's my belief and intention that this implementation be ready for other platforms too (some Intel-specific assumptions made), with a minimum of porting effort, though readying for some debugging is recommended.

Some potential bugs include:
- Power failure is being set (PMC PWR_FLR), so BootMode == 0x0. This bit
  is RW/1C, so mitigate it. Until finalised and I close the laptop
  chassis, I don't know if this is a bug in Kabylake's PchPmcLib.
- Very early in testing I saw a memory init error, which means that
  self-refresh failed. A BaseMemoryTest() predictably failed too,
  inserted before the PEI core installs memory. Either this was fixed
  in the code as I finished the implementation, or it's a bug. A major
  difference in build options is SerialPortSpiFlash ->
  I2cHdmiDebugSerialPortLib, but this seemed irrelevant. If it's simply
  the finalised implementation, I think this isn't worth a diff against
  the reflog.

Cc: Sai Chaganty <rangasai.v.chaganty@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Ankit Sinha <ankit.sinha@intel.com>
Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jeremy Soller <jeremy@system76.com>
Signed-off-by: Benjamin Doron <benjamin.doron00@gmail.com>

Benjamin Doron (4):
  MinPlatformPkg: Add SmmLockBox to build
  S3FeaturePkg: Implement working S3 resume
  MinPlatformPkg: Implement working S3 resume
  KabylakeOpenBoardPkg: Example of board S3

 .../S3FeaturePkg/Include/PostMemory.fdf       |  12 ++
 .../S3FeaturePkg/Include/PreMemory.fdf        |   8 +-
 .../S3FeaturePkg/Include/S3Feature.dsc        |  36 +++-
 .../S3FeaturePkg/S3Dxe/S3Dxe.c                | 155 ++++++++++++++++++
 .../S3FeaturePkg/S3Dxe/S3Dxe.inf              |  49 ++++++
 .../S3FeaturePkg/S3FeaturePkg.dsc             |   3 +
 .../S3FeaturePkg/S3Pei/S3Pei.c                |  83 +++++++++-
 .../S3FeaturePkg/S3Pei/S3Pei.inf              |   8 +-
 .../PeiFspMiscUpdUpdateLib.c                  |  12 +-
 .../PeiSaPolicyUpdate.c                       |  12 +-
 .../PeiAspireVn7Dash572GInitPreMemLib.c       |  38 +++--
 .../BoardInitLib/PeiBoardInitPreMemLib.inf    |   3 +
 .../AspireVn7Dash572G/OpenBoardPkg.dsc        |  21 +++
 .../AspireVn7Dash572G/OpenBoardPkgPcd.dsc     |  16 +-
 .../PeiSiliconPolicyUpdateLib.c               |  11 +-
 .../PeiSiliconPolicyUpdateLib.inf             |   1 +
 .../PeiFspMiscUpdUpdateLib.c                  |  11 +-
 .../PeiSaPolicyUpdate.c                       |  12 +-
 .../BoardInitLib/PeiBoardInitPreMemLib.inf    |   1 +
 .../BoardInitLib/PeiGalagoPro3InitPreMemLib.c |  27 ++-
 .../PeiMultiBoardInitPreMemLib.inf            |   1 +
 .../GalagoPro3/OpenBoardPkg.dsc               |  15 ++
 .../GalagoPro3/OpenBoardPkgPcd.dsc            |   2 +-
 .../PeiFspMiscUpdUpdateLib.c                  |  12 +-
 .../PeiSaPolicyUpdate.c                       |  12 +-
 .../BoardInitLib/PeiBoardInitPreMemLib.inf    |   1 +
 .../PeiKabylakeRvp3InitPreMemLib.c            |  27 ++-
 .../PeiMultiBoardInitPreMemLib.inf            |   1 +
 .../KabylakeRvp3/OpenBoardPkg.dsc             |  12 ++
 .../KabylakeRvp3/OpenBoardPkgPcd.dsc          |   2 +-
 .../PeiSiliconPolicyUpdateLib.c               |  11 +-
 .../PeiSiliconPolicyUpdateLib.inf             |   1 +
 .../FspWrapperHobProcessLib.c                 |  69 +++++++-
 .../PeiFspWrapperHobProcessLib.inf            |   2 +
 .../Include/AcpiS3MemoryNvData.h              |  22 +++
 .../Include/Dsc/CoreDxeInclude.dsc            |   1 +
 .../Include/Dsc/CorePeiInclude.dsc            |   2 +
 .../Include/Fdf/CoreOsBootInclude.fdf         |   1 +
 .../Include/Fdf/CorePostMemoryInclude.fdf     |   4 +
 39 files changed, 665 insertions(+), 52 deletions(-)  create mode 100644 Features/Intel/PowerManagement/S3FeaturePkg/S3Dxe/S3Dxe.c
 create mode 100644 Features/Intel/PowerManagement/S3FeaturePkg/S3Dxe/S3Dxe.inf
 create mode 100644 Platform/Intel/MinPlatformPkg/Include/AcpiS3MemoryNvData.h

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