UEFI 基础教程（五） - PPI 初探

一、编写源代码

编写C:\edkii\OvmfPkg\MyHelloWorldInstallPPI\MyHelloWorldInstallPPI.c，

#include <uefi.h>
#include <Library/UefiLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/PeimEntryPoint.h>
#include <Library/PeiServicesLib.h>
#include <Library/PeiServicesTablePointerLib.h>
#include <Pi/PiHob.h>
#include <Pi/PiPeiCis.h>

EFI_GUID gMyHelloWorldPEIGUID = { 0xbdb38129, 0x4d65, 0x39f4, { 0x72, 0x12, 0x68, 0xcf, 0x5a, 0x19, 0xa, 0xf8 }};

EFI_STATUS
EFIAPI
PrintHelloMsg (
  IN CHAR16 * Msg
  )
{
  DEBUG ((EFI_D_ERROR, "[MyHelloWorldPPI] PrintHelloMsg : %s \n",Msg));
  return EFI_SUCCESS;
}

typedef EFI_STATUS (EFIAPI * PRINTMSG)(CHAR16 *Msg);
typedef struct _EFI_HELLOWORLD_PROTOCOL  {
    PRINTMSG PrintMsg;
}EFI_HELLOWORLD_PROTOCOL;

EFI_HELLOWORLD_PROTOCOL mHelloWorldPpi = {
    PrintHelloMsg
};

EFI_PEI_PPI_DESCRIPTOR     mPpiListCodePpi = {
  (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  &gMyHelloWorldPEIGUID,
  &mHelloWorldPpi
};

EFI_STATUS
EFIAPI
MyHelloWorldInstallPPIEntry(
  IN       EFI_PEI_FILE_HANDLE  FileHandle,
  IN CONST EFI_PEI_SERVICES     **PeiServices
)
{
  EFI_STATUS                              Status = EFI_SUCCESS;
  DEBUG ((EFI_D_ERROR, "[MyHelloWorldPPI] MyHelloWorldInstallPPIEntry Start..\n"));
  PeiServicesInstallPpi  (&mPpiListCodePpi);
  DEBUG ((EFI_D_ERROR, "[MyHelloWorldPPI] MyHelloWorldInstallPPIEntry End..\n"));

  return Status;
}

编写C:\edkii\OvmfPkg\MyHelloWorldInstallPPI\MyHelloWorldInstallPPI.inf，

[Defines] 
  INF_VERSION = 0x00010006 
  BASE_NAME = MyHelloWorldInstallPPI 
  FILE_GUID = 69E6DE5D-F09E-485E-9936-EB70FDCFC82A
  MODULE_TYPE = PEIM
  VERSION_STRING = 1.0
  ENTRY_POINT = MyHelloWorldInstallPPIEntry 
  
[Sources] 
  MyHelloWorldInstallPPI.c 
  
[Packages]
  MdePkg/MdePkg.dec
  ShellPkg/ShellPkg.dec 
  MdeModulePkg/MdeModulePkg.dec
  
[LibraryClasses]
  BaseLib
  PeimEntryPoint
  BaseMemoryLib
  DebugLib
  PeiServicesLib
  PrintLib
  #PeiLib
  #EfiCommonLib

[depex]
  TRUE

编写 C:\edkii\OvmfPkg\MyHelloWorldLocatePPI\MyHelloWorldLocatePPI.c

#include <uefi.h>
#include <Library/UefiLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/PeimEntryPoint.h>
#include <Library/PeiServicesLib.h>
#include <Library/PeiServicesTablePointerLib.h>
#include <Pi/PiHob.h>

EFI_GUID gMyHelloWorldPEIGUID = { 0xbdb38129, 0x4d65, 0x39f4, { 0x72, 0x12, 0x68, 0xcf, 0x5a, 0x19, 0xa, 0xf8 }};


typedef EFI_STATUS (EFIAPI * PRINTMSG)(CHAR16 *Msg);
typedef struct _EFI_HELLOWORLD_PROTOCOL  {
    PRINTMSG PrintMsg;
}EFI_HELLOWORLD_PROTOCOL;

//ShellCEntryLib call user interface ShellAppMain
EFI_STATUS
EFIAPI
MyHelloWorldLocatePPIEntry(
  IN       EFI_PEI_FILE_HANDLE  FileHandle,
  IN CONST EFI_PEI_SERVICES     **PeiServices
)
{
  EFI_STATUS  Status = EFI_SUCCESS;
  EFI_HELLOWORLD_PROTOCOL *mHelloWorldPpi = NULL;
  DEBUG ((EFI_D_ERROR, "[MyHelloWorldPPI] MyHelloWorldLocatePPIEntry Locate PPI Start..\n"));
  Status = PeiServicesLocatePpi (
           &gMyHelloWorldPEIGUID,
           0,
           NULL,
           (VOID **)&mHelloWorldPpi
           );
  if (EFI_ERROR(Status)){
      DEBUG ((EFI_D_ERROR, "[MyHelloWorldPPI] MyHelloWorldLocatePPIEntry Locate PPI Fail..%r\n",Status));
      return Status;
  }
  mHelloWorldPpi->PrintMsg(L"2019 CSDN Locate PPI Hello World ...\n");
  DEBUG ((EFI_D_ERROR, "[MyHelloWorldPPI] MyHelloWorldLocatePPIEntry Locate PPI End..\n"));
  return Status;
}

编写 C:\edkii\OvmfPkg\MyHelloWorldLocatePPI\MyHelloWorldLocatePPI.inf

[Defines] 
  INF_VERSION = 0x00010006 
  BASE_NAME = MyHelloWorldLocatePPI 
  FILE_GUID = 69E6DE6D-F39F-485f-9037-EB70FDCFC82B
  MODULE_TYPE = PEIM
  VERSION_STRING = 1.0
  ENTRY_POINT = MyHelloWorldLocatePPIEntry 
  
[Sources] 
  MyHelloWorldLocatePPI.c 
  
[Packages]
  MdePkg/MdePkg.dec
  ShellPkg/ShellPkg.dec 
  MdeModulePkg/MdeModulePkg.dec
  
[LibraryClasses]
  BaseLib
  PeimEntryPoint
  BaseMemoryLib
  DebugLib
  PeiServicesLib
  PrintLib
  #PeiLib
  #EfiCommonLib

[depex]
  TRUE

修改C:\edkii\OvmfPkg\OvmfPkgX64.dsc

[Components]
...    
#
# PEI Phase modules
#
INF  OvmfPkg/MyHelloWorldInstallPPI/MyHelloWorldInstallPPI.inf
INF  OvmfPkg/MyHelloWorldLocatePPI/MyHelloWorldLocatePPI.inf
...

修改C:\edkii\OvmfPkg\OvmfPkgX64.fdf

[FV.PEIFV]
...
#
# PEI Phase modules
#
INF  OvmfPkg/MyHelloWorldInstallPPI/MyHelloWorldInstallPPI.inf
INF  OvmfPkg/MyHelloWorldLocatePPI/MyHelloWorldLocatePPI.inf
...

二、编译生成EFI文件

运行edksetup.bat编译整个OvmfPkg Package

三、运行HelloWorld PPI Driver

拷贝 C:\edkii\Build\OvmfX64\DEBUG_VS2013x86\FV\OVMF.fd 到C:\qemu
执行setup-qemu-x64.bat | findstr MyHelloWorldPPI 的输出如下，

四、小结

PPI(PEIM-to-PEIM Interface) 是一种PEIM驱动之间的通信方式，本文中MyHelloWorldInstallPPI模块通过PeiServicesInstallPpi提供了mPpiListCodePpi 服务，而MyHelloWorldLocatePPI模块通过PeiServicesLocatePpi获取了mPpiListCodePpi对象，通过访问对象的成员函数即可完成对驱动MyHelloWorldInstallPPI资源的访问。