Add lesson 36

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>

9 files changed, 309 insertions, 0 deletions

diff --git a/Lessons/Lesson_36/README.md b/Lessons/Lesson_36/README.md
new file mode 100644
index 0000000..f6d64ad
--- /dev/null
+++ b/Lessons/Lesson_36/README.md
@@ -0,0 +1,157 @@
+In this lesson we will try to create the most simple library.
+
+Usually libraries are present in these directories:
+```
+<Pkg Name>/Library/<Library Name>/               <---- inf and source files for the library (=library implementation)
+<Pkg Name>/Include/Library/                      <---- library headers (=library interface)
+```
+
+Create folders for our `SimpleLibrary`:
+```
+$ mkdir -p UefiLessonsPkg/Library/SimpleLibrary/
+$ mkdir -p UefiLessonsPkg/Include/Library/
+```
+
+First let's implement the header file, the interface for our library. Our `SimpleLibrary` would contain the only function `Plus2` that would receive a `number` and return a `number+2`.
+Therefore the content in the header file (`UefiLessonsPkg/Include/Library/SimpleLibrary.h`) would look like this:
+```
+UINTN Plus2(UINTN number);
+```
+
+No harder the library implementation file `UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.c`:
+```
+#include <Library/SimpleLibrary.h>
+
+UINTN Plus2(UINTN number) {
+  return number+2;
+}
+```
+
+This is really a simple library, it stands to its name!
+
+Now we need to create an INF file for the library `UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf`:
+```
+[Defines]
+  INF_VERSION                    = 1.25
+  BASE_NAME                      = SimpleLibrary
+  FILE_GUID                      = 826c8951-5bd2-4d72-a9d9-f7ab48684117
+  MODULE_TYPE                    = UEFI_APPLICATION
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = SimpleLibrary | UEFI_APPLICATION
+
+[Sources]
+  SimpleLibrary.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+```
+
+The interesting string here is the:
+```
+LIBRARY_CLASS = SimpleLibrary | UEFI_APPLICATION
+```
+It says that this library can only be used in modules with a type `UEFI_APPLICATION`. If you would say here `DXE_DRIVER` and try to link it to some of you UEFI applications, build process would fail. The error message would look like this:
+```
+build.py...
+/home/kostr/tiano/edk2/UefiLessonsPkg/UefiLessonsPkg.dsc(...): error 1001: Module type [UEFI_APPLICATION] is not supported by library instance [/home/kostr/tiano/edk2/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf]
+        consumed by [/home/kostr/tiano/edk2/UefiLessonsPkg/<path to your app inf file>]
+```
+
+Now we need to include our library to our package DSC file `UefiLessonsPkg/UefiLessonsPkg.dsc`, so it would get build on a package build:
+```
+[Components]
+  ...
+  UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf
+```
+
+But if you try to build our package now build would fail with a message:
+```
+/home/kostr/tiano/edk2/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.c:1:10: fatal error: Library/SimpleLibrary.h: No such file or directory
+    1 | #include <Library/SimpleLibrary.h>
+      |          ^~~~~~~~~~~~~~~~~~~~~~~~~
+compilation terminated.
+```
+The reason of that is a fact that our `UefiLessonsPkg/Include/Library/` folder is not recognized by a build system as a place where headers might be.
+
+To fix it we need to add to our `UefiLessonsPkg/UefiLessonsPkg.dec` file `[Includes]` section:
+```
+[Includes]
+  Include
+```
+
+And include this `UefiLessonsPkg/UefiLessonsPkg.dec` file to the library module INF file section `[Packages]`:
+```
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiLessonsPkg/UefiLessonsPkg.dec
+```
+
+Now we are good, build would succeed.
+
+# SimpleLibraryUser
+
+Now let's create an application that would use our library.
+
+UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.c:
+```
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Library/SimpleLibrary.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  Print(L"%d\n", Plus2(3));
+
+  return EFI_SUCCESS;
+}
+```
+
+UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.inf
+```
+[Defines]
+  INF_VERSION                    = 1.25
+  BASE_NAME                      = SimpleLibraryUser
+  FILE_GUID                      = 22a1f57c-21ca-4011-9133-e3df0d01dace
+  MODULE_TYPE                    = UEFI_APPLICATION
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = UefiMain
+
+[Sources]
+  SimpleLibraryUser.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiLessonsPkg/UefiLessonsPkg.dec                  <--- we need to include this for the same reason as in library INF file (for the header search)
+
+[LibraryClasses]
+  UefiApplicationEntryPoint
+  UefiLib
+  SimpleLibrary                                      <--- library is included as usual
+```
+
+Now add modifications to the `UefiLessonsPkg/UefiLessonsPkg.dsc`:
+```
+[LibraryClasses]
+  ...
+  SimpleLibrary|UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf
+
+[Components]
+  ...
+  UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.inf
+```
+Here we've added implementation for our library class and added our new module to the package components.
+
+If you build everything now and execute it under OVMF, you would get:
+```
+FS0:\> SimpleLibraryUser.efi
+5
+```
+
+`3+2` is indeed `5`, so our library works correctly!
+
diff --git a/Lessons/Lesson_36/UefiLessonsPkg/Include/Library/SimpleLibrary.h b/Lessons/Lesson_36/UefiLessonsPkg/Include/Library/SimpleLibrary.h
new file mode 100644
index 0000000..105bc87
--- /dev/null
+++ b/Lessons/Lesson_36/UefiLessonsPkg/Include/Library/SimpleLibrary.h
@@ -0,0 +1,2 @@
+UINTN Plus2(UINTN number);
+
diff --git a/Lessons/Lesson_36/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.c b/Lessons/Lesson_36/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.c
new file mode 100644
index 0000000..acffba4
--- /dev/null
+++ b/Lessons/Lesson_36/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.c
@@ -0,0 +1,5 @@
+#include <Library/SimpleLibrary.h>
+
+UINTN Plus2(UINTN number) {
+  return number+2;
+}
diff --git a/Lessons/Lesson_36/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf b/Lessons/Lesson_36/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf
new file mode 100644
index 0000000..92027a4
--- /dev/null
+++ b/Lessons/Lesson_36/UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf
@@ -0,0 +1,15 @@
+[Defines]
+  INF_VERSION                    = 1.25
+  BASE_NAME                      = SimpleLibrary
+  FILE_GUID                      = 826c8951-5bd2-4d72-a9d9-f7ab48684117
+  MODULE_TYPE                    = UEFI_APPLICATION
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = SimpleLibrary | UEFI_APPLICATION
+
+[Sources]
+  SimpleLibrary.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiLessonsPkg/UefiLessonsPkg.dec
+
diff --git a/Lessons/Lesson_36/UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.c b/Lessons/Lesson_36/UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.c
new file mode 100644
index 0000000..9747b97
--- /dev/null
+++ b/Lessons/Lesson_36/UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.c
@@ -0,0 +1,16 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Library/SimpleLibrary.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  Print(L"%d\n", Plus2(3));
+
+  return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_36/UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.inf b/Lessons/Lesson_36/UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.inf
new file mode 100644
index 0000000..d7e5be8
--- /dev/null
+++ b/Lessons/Lesson_36/UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.inf
@@ -0,0 +1,20 @@
+[Defines]
+  INF_VERSION                    = 1.25
+  BASE_NAME                      = SimpleLibraryUser
+  FILE_GUID                      = 22a1f57c-21ca-4011-9133-e3df0d01dace
+  MODULE_TYPE                    = UEFI_APPLICATION
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = UefiMain
+
+[Sources]
+  SimpleLibraryUser.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiLessonsPkg/UefiLessonsPkg.dec
+
+[LibraryClasses]
+  UefiApplicationEntryPoint
+  UefiLib
+  SimpleLibrary
+
diff --git a/Lessons/Lesson_36/UefiLessonsPkg/UefiLessonsPkg.dec b/Lessons/Lesson_36/UefiLessonsPkg/UefiLessonsPkg.dec
new file mode 100644
index 0000000..cc355aa
--- /dev/null
+++ b/Lessons/Lesson_36/UefiLessonsPkg/UefiLessonsPkg.dec
@@ -0,0 +1,34 @@
+[Defines]

+  DEC_SPECIFICATION              = 0x00010005

+  PACKAGE_NAME                   = UefiLessonsPkg

+  PACKAGE_GUID                   = 7e7edbba-ca2c-4177-a3f0-d3371358773a

+  PACKAGE_VERSION                = 1.01

+

+[Includes]

+  Include

+

+[Guids]

+  # FILE_GUID as defined in UefiLessonsPkg/HelloWorld/HelloWorld.inf

+  gHelloWorldFileGuid            = {0x2e55fa38, 0xf148, 0x42d3, {0xaf, 0x90, 0x1b, 0xe2, 0x47, 0x32, 0x3e, 0x30}}

+  gUefiLessonsPkgTokenSpaceGuid = {0x150cab53, 0xad47, 0x4385, {0xb5, 0xdd, 0xbc, 0xfc, 0x76, 0xba, 0xca, 0xf0}}

+

+[Protocols]

+

+[PcdsFixedAtBuild]

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyVar32|42|UINT32|0x00000001

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyVar32_1|42|UINT32|0x00000002

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyVar32_2|42|UINT32|0x00000003

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyVarBool|FALSE|BOOLEAN|0x00000004

+

+[PcdsPatchableInModule]

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyPatchableVar32|0x31313131|UINT32|0x10000001

+

+[PcdsFeatureFlag]

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyFeatureFlagVar|FALSE|BOOLEAN|0x20000001

+

+[PcdsDynamic]

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyDynamicVar32|0x38323232|UINT32|0x30000001

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyDynamicVar32_1|42|UINT32|0x30000002

+

+[PcdsDynamicEx]

+  gUefiLessonsPkgTokenSpaceGuid.PcdMyDynamicExVar32|0x38333333|UINT32|0x40000001

diff --git a/Lessons/Lesson_36/UefiLessonsPkg/UefiLessonsPkg.dsc b/Lessons/Lesson_36/UefiLessonsPkg/UefiLessonsPkg.dsc
new file mode 100644
index 0000000..c42b57d
--- /dev/null
+++ b/Lessons/Lesson_36/UefiLessonsPkg/UefiLessonsPkg.dsc
@@ -0,0 +1,59 @@
+[Defines]
+  DSC_SPECIFICATION              = 0x0001001C
+  PLATFORM_GUID                  = 3db7270f-ffac-4139-90a4-0ae68f3f8167
+  PLATFORM_VERSION               = 0.01
+  PLATFORM_NAME                  = UefiLessonsPkg
+  SKUID_IDENTIFIER               = DEFAULT
+  SUPPORTED_ARCHITECTURES        = X64
+  BUILD_TARGETS                  = RELEASE
+
+
+[LibraryClasses]
+  UefiApplicationEntryPoint|MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf
+  UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.inf
+  DebugLib|MdePkg/Library/UefiDebugLibConOut/UefiDebugLibConOut.inf
+  BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
+  #PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
+  PcdLib|MdePkg/Library/DxePcdLib/DxePcdLib.inf
+  BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
+  RegisterFilterLib|MdePkg/Library/RegisterFilterLibNull/RegisterFilterLibNull.inf
+  PrintLib|MdePkg/Library/BasePrintLib/BasePrintLib.inf
+  DebugPrintErrorLevelLib|MdePkg/Library/BaseDebugPrintErrorLevelLib/BaseDebugPrintErrorLevelLib.inf
+  UefiLib|MdePkg/Library/UefiLib/UefiLib.inf
+  MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
+  DevicePathLib|MdePkg/Library/UefiDevicePathLib/UefiDevicePathLib.inf
+  UefiRuntimeServicesTableLib|MdePkg/Library/UefiRuntimeServicesTableLib/UefiRuntimeServicesTableLib.inf
+  ShellCEntryLib|ShellPkg/Library/UefiShellCEntryLib/UefiShellCEntryLib.inf
+  ShellLib|ShellPkg/Library/UefiShellLib/UefiShellLib.inf
+  FileHandleLib|MdePkg/Library/UefiFileHandleLib/UefiFileHandleLib.inf  
+  HiiLib|MdeModulePkg/Library/UefiHiiLib/UefiHiiLib.inf
+  SortLib|MdeModulePkg/Library/UefiSortLib/UefiSortLib.inf
+  UefiHiiServicesLib|MdeModulePkg/Library/UefiHiiServicesLib/UefiHiiServicesLib.inf
+  SimpleLibrary|UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf
+
+[Components]
+  UefiLessonsPkg/SimplestApp/SimplestApp.inf
+  UefiLessonsPkg/HelloWorld/HelloWorld.inf
+  UefiLessonsPkg/ImageHandle/ImageHandle.inf
+  UefiLessonsPkg/ImageInfo/ImageInfo.inf
+  UefiLessonsPkg/MemoryInfo/MemoryInfo.inf
+  UefiLessonsPkg/SimpleShellApp/SimpleShellApp.inf
+  UefiLessonsPkg/ListVariables/ListVariables.inf
+  UefiLessonsPkg/ShowBootVariables/ShowBootVariables.inf
+  UefiLessonsPkg/InteractiveApp/InteractiveApp.inf
+  #UefiLessonsPkg/GOPInfo/GOPInfo.inf
+  #UefiLessonsPkg/HiiMenu/HiiMenu.inf
+  #UefiLessonsPkg/TestGlyphs/TestGlyphs.inf
+  #UefiLessonsPkg/ShowHii/ShowHii.inf
+  UefiLessonsPkg/PCDLesson/PCDLesson.inf
+  UefiLessonsPkg/ShowTables/ShowTables.inf
+  UefiLessonsPkg/AcpiInfo/AcpiInfo.inf
+  UefiLessonsPkg/SaveBGRT/SaveBGRT.inf
+  UefiLessonsPkg/ListPCI/ListPCI.inf
+  UefiLessonsPkg/PCIRomInfo/PCIRomInfo.inf
+  UefiLessonsPkg/Library/SimpleLibrary/SimpleLibrary.inf
+  UefiLessonsPkg/SimpleLibraryUser/SimpleLibraryUser.inf
+
+[PcdsFixedAtBuild]
+  gUefiLessonsPkgTokenSpaceGuid.PcdMyVar32_2|44
+
diff --git a/README.md b/README.md
index 9ed9ed6..4fd30af 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,7 @@ Lessons description:
 - Lesson 33: Use `EfiRom` utility for parsing and creation of PCI Option ROM images 
 - Lesson 34: Create a simple UEFI driver. Use `load`/`unload` UEFI shell commands to work with a driver image 
 - Lesson 35: Investigate ways how to add `acpiview` command functionality to your shell
+- Lesson 36: Create a simple library and use it in an app
 
 ______