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authorKonstantin Aladyshev <aladyshev22@gmail.com>2021-07-10 00:04:40 +0300
committerKonstantin Aladyshev <aladyshev22@gmail.com>2021-07-10 00:04:40 +0300
commit6064c1e48b622f53538f4df9bdd402c607a87d51 (patch)
tree93d3c937b9568568307fd2ff7053a30c538ad72a /Lessons/Lesson_20
parenta9c375c80c3505be794ec2b5d5bb90de27ef0d42 (diff)
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Move lessons to separate folder
Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Diffstat (limited to 'Lessons/Lesson_20')
-rw-r--r--Lessons/Lesson_20/Conf/target.txt7
-rw-r--r--Lessons/Lesson_20/README.md108
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.c19
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.inf18
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.c105
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.inf18
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.c44
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.inf22
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.c34
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.inf18
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.c46
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.inf19
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.c215
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.inf21
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.c15
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.inf22
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.c93
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.inf19
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.c14
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.inf19
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.c10
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.inf16
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dec20
-rw-r--r--Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dsc39
24 files changed, 961 insertions, 0 deletions
diff --git a/Lessons/Lesson_20/Conf/target.txt b/Lessons/Lesson_20/Conf/target.txt
new file mode 100644
index 0000000..c109dcf
--- /dev/null
+++ b/Lessons/Lesson_20/Conf/target.txt
@@ -0,0 +1,7 @@
+ACTIVE_PLATFORM = UefiLessonsPkg/UefiLessonsPkg.dsc
+TARGET = RELEASE
+TARGET_ARCH = X64
+TOOL_CHAIN_CONF = Conf/tools_def.txt
+TOOL_CHAIN_TAG = GCC5
+BUILD_RULE_CONF = Conf/build_rule.txt
+
diff --git a/Lessons/Lesson_20/README.md b/Lessons/Lesson_20/README.md
new file mode 100644
index 0000000..46a4c5b
--- /dev/null
+++ b/Lessons/Lesson_20/README.md
@@ -0,0 +1,108 @@
+The Platform Configuration Database (PCD) is a database that contains a variety of current platform settings or directives that can be accessed by a driver or application.
+
+You can checkout edk2 specification https://edk2-docs.gitbook.io/edk-ii-pcd-specification/ or https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/edkii-platform-config-database-entries-paper.pdf for more explanation on PCD.
+
+PCD entry is also called PCD, so we will use this term further.
+
+The PCD entry is defined in a DEC file in a format:
+```
+<TokenSpaceGuidCName>.<PcdCName>|<DefaultValue>|<DatumType>|<Token>
+```
+`<TokenSpaceGuidCName>` is a GUID value, `<Token>` is a 32-bit value. Together they are used to uniqely identify PCD.
+
+First let's declare a Token Space that would contain all our PCDs.
+Usually in is defined as a `g<PackageName>TokenSpaceGuid`, so add this to our `UefiLessonsPkg/UefiLessonsPkg.dec`:
+```
+[Guids]
+ ...
+ gUefiLessonsPkgTokenSpaceGuid = {0x150cab53, 0xad47, 0x4385, {0xb5, 0xdd, 0xbc, 0xfc, 0x76, 0xba, 0xca, 0xf0}}
+```
+
+Now we can define our PCDs in the same *.dec file. Let's start with `UINT32 PcdMyVar32 = 42`:
+```
+[PcdsFixedAtBuild]
+ gEfiUefiLessonsPkgTokenSpaceGuid.PcdMyVar32|42|UINT32|0x00000001
+```
+
+Now create an app `PCDLesson` with the following code in its entry point function:
+```
+Print(L"PcdMyVar32=%d\n", FixedPcdGet32(PcdMyVar32));
+```
+To use `FixedPcdGet32` in our code we need to add the necessary include:
+```
+#include <Library/PcdLib.h>
+```
+If you check out this file (https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Library/PcdLib.h) you'll see that `FixedPcdGet32` is simply a define statement:
+```
+#define FixedPcdGet32(TokenName) _PCD_VALUE_##TokenName
+```
+
+If we try to build our app now, build will fail, as we don't have such define in our app:
+```
+/home/kostr/tiano/edk2/MdePkg/Include/Library/PcdLib.h:97:45: error: ‘_PCD_VALUE_PcdMyVar32’ undeclared (first use in this function)
+ 97 | #define FixedPcdGet32(TokenName) _PCD_VALUE_##TokenName
+ | ^~~~~~~~~~~
+```
+
+To fix this we need to add this PCD to our app `*.inf` file:
+```
+[FixedPcd]
+ gUefiLessonsPkgTokenSpaceGuid.PcdMyVar32
+```
+
+Also we need to include "dec" file that defines this PCD:
+```
+[Packages]
+ ...
+ UefiLessonsPkg/UefiLessonsPkg.dec
+```
+
+Now compilation would succeed.
+
+If you check out the content of autogenerated files `AutoGen.h`/`AutoGen.c`, you'll see, that our PCD is there.
+
+Build/UefiLessonsPkg/RELEASE_GCC5/X64/UefiLessonsPkg/PCDLesson/PCDLesson/DEBUG/AutoGen.h
+```
+// Definition of PCDs used in this module
+
+#define _PCD_TOKEN_PcdMyVar32 0U
+#define _PCD_SIZE_PcdMyVar32 4
+#define _PCD_GET_MODE_SIZE_PcdMyVar32 _PCD_SIZE_PcdMyVar32
+#define _PCD_VALUE_PcdMyVar32 42U
+extern const UINT32 _gPcd_FixedAtBuild_PcdMyVar32;
+#define _PCD_GET_MODE_32_PcdMyVar32 _gPcd_FixedAtBuild_PcdMyVar32
+//#define _PCD_SET_MODE_32_PcdMyVar32 ASSERT(FALSE) // It is not allowed to set value for a FIXED_AT_BUILD PCD
+```
+
+Build/UefiLessonsPkg/RELEASE_GCC5/X64/UefiLessonsPkg/PCDLesson/PCDLesson/DEBUG/AutoGen.c
+```
+// Definition of PCDs used in this module
+GLOBAL_REMOVE_IF_UNREFERENCED const UINT32 _gPcd_FixedAtBuild_PcdMyVar32 = _PCD_VALUE_PcdMyVar32;
+```
+
+So in our case preprocessor expands code like this:
+```
+FixedPcdGet32(PcdMyVar32) -> _PCD_VALUE_PcdMyVar32 -> 42U
+```
+
+If you execute app code under OVMF:
+```
+FS0:\> PCDLesson.efi
+PcdMyVar32=42
+```
+
+There are multiple types of PCDs. `FixedAtBuild` PCD is only one of them. In our code we've used `FixedPcdGet` call to get PCD value, this call would only work if PCD is `FixedAtBuild`. However there is a generic `PcdGet` call that can be used to get a value of PCD regardless its type.
+https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Library/PcdLib.h:
+```
+#define PcdGet32(TokenName) _PCD_GET_MODE_32_##TokenName
+```
+
+In our case this would expand to:
+```
+PcdGet32(PcdMyVar32) -> _PCD_GET_MODE_32_PcdMyVar32 -> _gPcd_FixedAtBuild_PcdMyVar32
+```
+The latter one is a variable that is defined in a `AutoGen.c` file:
+```
+ GLOBAL_REMOVE_IF_UNREFERENCED const UINT32 _gPcd_FixedAtBuild_PcdMyVar32 = 42U;
+```
+So as you can see result would be the same. The difference is that `PcdGet` would work with other PCD types, that we would cover in the next lessons.
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.c b/Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.c
new file mode 100644
index 0000000..29a4812
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.c
@@ -0,0 +1,19 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ SystemTable->ConOut->OutputString(SystemTable->ConOut, L"Hello World!\n");
+ gST->ConOut->OutputString(gST->ConOut, L"Hello again!\n");
+ Print(L"Bye!\n");
+
+ UINTN Index;
+ gBS->WaitForEvent(1, &(gST->ConIn->WaitForKey), &Index);
+ gST->ConIn->Reset(gST->ConIn, FALSE);
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.inf b/Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.inf
new file mode 100644
index 0000000..d65ca2e
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/HelloWorld/HelloWorld.inf
@@ -0,0 +1,18 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = HelloWorld
+ FILE_GUID = 2e55fa38-f148-42d3-af90-1be247323e30
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ HelloWorld.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.c b/Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.c
new file mode 100644
index 0000000..32e9c43
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.c
@@ -0,0 +1,105 @@
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+typedef struct {
+ UINTN Signature;
+ /// All handles list of IHANDLE
+ LIST_ENTRY AllHandles;
+ /// List of PROTOCOL_INTERFACE's for this handle
+ LIST_ENTRY Protocols;
+ UINTN LocateRequest;
+ /// The Handle Database Key value when this handle was last created or modified
+ UINT64 Key;
+} IHANDLE;
+
+typedef struct {
+ UINTN Signature;
+ /// Link Entry inserted to mProtocolDatabase
+ LIST_ENTRY AllEntries;
+ /// ID of the protocol
+ EFI_GUID ProtocolID;
+ /// All protocol interfaces
+ LIST_ENTRY Protocols;
+ /// Registerd notification handlers
+ LIST_ENTRY Notify;
+} PROTOCOL_ENTRY;
+
+typedef struct {
+ UINTN Signature;
+ /// Link on IHANDLE.Protocols
+ LIST_ENTRY Link;
+ /// Back pointer
+ IHANDLE *Handle;
+ /// Link on PROTOCOL_ENTRY.Protocols
+ LIST_ENTRY ByProtocol;
+ /// The protocol ID
+ PROTOCOL_ENTRY *Protocol;
+ /// The interface value
+ VOID *Interface;
+ /// OPEN_PROTOCOL_DATA list
+ LIST_ENTRY OpenList;
+ UINTN OpenListCount;
+
+} PROTOCOL_INTERFACE;
+
+
+#define offsetof(a,b) ((INTN)(&(((a*)(0))->b)))
+
+#define container_of(ptr, type, member) ({ \
+ const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+ (type *)( (char *)__mptr - offsetof(type,member) );})
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ IHANDLE* MyHandle = ImageHandle;
+ Print(L"Signature: %c %c %c %c\n", (MyHandle->Signature >> 0) & 0xff,
+ (MyHandle->Signature >> 8) & 0xff,
+ (MyHandle->Signature >> 16) & 0xff,
+ (MyHandle->Signature >> 24) & 0xff);
+
+ Print(L"Back Protocol Interface Link: %p\n", MyHandle->Protocols.BackLink);
+ Print(L"Forward Protocol Interface Link: %p\n", MyHandle->Protocols.ForwardLink);
+
+ LIST_ENTRY *FirstLink = MyHandle->Protocols.ForwardLink;
+ LIST_ENTRY *CurrentLink = FirstLink;
+ do {
+ PROTOCOL_INTERFACE* MyProtocolInterface = container_of(CurrentLink, PROTOCOL_INTERFACE, Link);
+
+ Print(L"\n");
+ Print(L"Current Link: %p\n", CurrentLink);
+ Print(L"Signature: %x %x %x %x\n", (MyProtocolInterface->Signature >> 0) & 0xff,
+ (MyProtocolInterface->Signature >> 8) & 0xff,
+ (MyProtocolInterface->Signature >> 16) & 0xff,
+ (MyProtocolInterface->Signature >> 24) & 0xff);
+
+ Print(L"Back Link: %p\n", MyProtocolInterface->Link.BackLink);
+ Print(L"Forward Link: %p\n", MyProtocolInterface->Link.ForwardLink);
+ Print(L"GUID=%g\n", MyProtocolInterface->Protocol->ProtocolID);
+ CurrentLink = MyProtocolInterface->Link.ForwardLink;
+ } while (CurrentLink != FirstLink);
+
+ Print(L"________\n");
+ EFI_GUID **ProtocolGuidArray;
+ UINTN ArrayCount;
+ //EFI_STATUS Status = gBS->ProtocolsPerHandle(NULL, // Use this to test %r Print formatting option
+ EFI_STATUS Status = gBS->ProtocolsPerHandle(ImageHandle,
+ &ProtocolGuidArray,
+ &ArrayCount);
+
+ if (!EFI_ERROR(Status)) {
+ for (int i=0; i<ArrayCount; i++) {
+ Print(L"%g\n", ProtocolGuidArray[i]);
+ }
+ FreePool(ProtocolGuidArray);
+ } else {
+ Print(L"ProtocolsPerHandle error: %r\n", Status);
+ }
+
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.inf b/Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.inf
new file mode 100644
index 0000000..34256ee
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ImageHandle/ImageHandle.inf
@@ -0,0 +1,18 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = ImageHandle
+ FILE_GUID = b68d3472-70c7-4928-841b-6566032e0a23
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ ImageHandle.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.c b/Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.c
new file mode 100644
index 0000000..c45570e
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.c
@@ -0,0 +1,44 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Protocol/LoadedImage.h>
+#include <Library/DevicePathLib.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+ EFI_LOADED_IMAGE_PROTOCOL* LoadedImage;
+
+ Status = gBS->HandleProtocol(
+ ImageHandle,
+ &gEfiLoadedImageProtocolGuid,
+ (VOID **) &LoadedImage
+ );
+
+ if (Status == EFI_SUCCESS) {
+ EFI_DEVICE_PATH_PROTOCOL* DevicePath;
+
+ Status = gBS->HandleProtocol(
+ ImageHandle,
+ &gEfiLoadedImageDevicePathProtocolGuid,
+ (VOID**) &DevicePath
+ );
+
+ if (Status == EFI_SUCCESS) {
+ Print(L"Image device: %s\n", ConvertDevicePathToText(DevicePath, FALSE, TRUE));
+ Print(L"Image file: %s\n", ConvertDevicePathToText(LoadedImage->FilePath, FALSE, TRUE)); // EFI_DEVICE_PATH_PROTOCOL *FilePath
+ Print(L"Image Base: %X\n", LoadedImage->ImageBase);
+ Print(L"Image Size: %X\n", LoadedImage->ImageSize);
+ } else {
+ Print(L"Can't get EFI_LOADED_IMAGE_PROTOCOL, Status=%r\n", Status);
+ }
+ } else {
+ Print(L"Can't get EFI_DEVICE_PATH_PROTOCOL, Status=%r\n", Status);
+ }
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.inf b/Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.inf
new file mode 100644
index 0000000..0ce54a6
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ImageInfo/ImageInfo.inf
@@ -0,0 +1,22 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = ImageInfo
+ FILE_GUID = b68d3472-70c7-4928-841b-6566032e0a23
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ ImageInfo.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+
+[Protocols]
+ gEfiLoadedImageProtocolGuid
+ gEfiLoadedImageDevicePathProtocolGuid
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.c b/Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.c
new file mode 100644
index 0000000..59c89a9
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.c
@@ -0,0 +1,34 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ UINTN Index;
+ EFI_INPUT_KEY Key;
+
+ Print(L"Try to guess the secret symbol!\n");
+ Print(L"To quit press 'q'\n");
+
+ while(TRUE) {
+ gBS->WaitForEvent(1, &(gST->ConIn->WaitForKey), &Index);
+ gST->ConIn->ReadKeyStroke(gST->ConIn, &Key);
+ Print(L"ScanCode = %04x, UnicodeChar = %04x (%c)\n", Key.ScanCode, Key.UnicodeChar, Key.UnicodeChar);
+
+ if (Key.UnicodeChar == 'k') {
+ Print(L"Correct!\n");
+ break;
+ } else if (Key.UnicodeChar == 'q') {
+ Print(L"Bye!\n");
+ break;
+ } else {
+ Print(L"Wrong!\n");
+ }
+ }
+ gST->ConIn->Reset(gST->ConIn, FALSE);
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.inf b/Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.inf
new file mode 100644
index 0000000..700b779
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/InteractiveApp/InteractiveApp.inf
@@ -0,0 +1,18 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = InteractiveApp
+ FILE_GUID = 1539451b-f300-41fa-a565-dde69c1bed66
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ InteractiveApp.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.c b/Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.c
new file mode 100644
index 0000000..1f3ef4a
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.c
@@ -0,0 +1,46 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+INTN EFIAPI ShellAppMain(IN UINTN Argc, IN CHAR16 **Argv)
+{
+ EFI_GUID VendorGuid;
+ UINTN VariableNameSize = sizeof (CHAR16);
+ CHAR16* VariableName = AllocateZeroPool(sizeof(CHAR16));
+ if (VariableName == NULL) {
+ Print(L"Error on AllocateZeroPool call\n");
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ while (TRUE)
+ {
+ UINTN VariableNameSizeOld = VariableNameSize;
+ EFI_STATUS Status = gRT->GetNextVariableName(&VariableNameSize, VariableName, &VendorGuid);
+ if (Status == EFI_SUCCESS) {
+ Print(L"%g: %s\n", VendorGuid, VariableName);
+ } else if (Status == EFI_BUFFER_TOO_SMALL) {
+ VariableName = ReallocatePool(VariableNameSizeOld, VariableNameSize, VariableName);
+ if (VariableName == NULL) {
+ Print(L"Error on ReallocatePool call\n");
+ return EFI_OUT_OF_RESOURCES;
+ }
+ Status = gRT->GetNextVariableName(&VariableNameSize, VariableName, &VendorGuid);
+ if (Status == EFI_SUCCESS) {
+ Print(L"%g: %s\n", VendorGuid, VariableName);
+ } else {
+ Print(L"Error on 'gRT->GetNextVariableName' call: %s\n", Status);
+ return Status;
+ }
+ } else if (Status == EFI_NOT_FOUND) {
+ FreePool(VariableName);
+ return EFI_SUCCESS;
+ } else {
+ Print(L"Error on 'gRT->GetNextVariableName' call: %s\n", Status);
+ return Status;
+ }
+ }
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.inf b/Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.inf
new file mode 100644
index 0000000..14e9fa2
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ListVariables/ListVariables.inf
@@ -0,0 +1,19 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = ListVariables
+ FILE_GUID = d66f68b2-3591-45af-bf5d-519152b9d877
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = ShellCEntryLib
+
+[Sources]
+ ListVariables.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+ ShellCEntryLib
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.c b/Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.c
new file mode 100644
index 0000000..8c3bcf2
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.c
@@ -0,0 +1,215 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+// for SetMem
+#include <Library/BaseMemoryLib.h>
+
+#include <Protocol/ShellParameters.h>
+
+const CHAR16 *memory_types[] = {
+ L"EfiReservedMemoryType",
+ L"EfiLoaderCode",
+ L"EfiLoaderData",
+ L"EfiBootServicesCode",
+ L"EfiBootServicesData",
+ L"EfiRuntimeServicesCode",
+ L"EfiRuntimeServicesData",
+ L"EfiConventionalMemory",
+ L"EfiUnusableMemory",
+ L"EfiACPIReclaimMemory",
+ L"EfiACPIMemoryNVS",
+ L"EfiMemoryMappedIO",
+ L"EfiMemoryMappedIOPortSpace",
+ L"EfiPalCode",
+ L"EfiPersistentMemory",
+ L"EfiMaxMemoryType"
+};
+
+
+const CHAR16 *memory_types_OS_view[] = {
+ L"reserved", // L"EfiReservedMemoryType",
+ L"usable", // L"EfiLoaderCode",
+ L"usable", // L"EfiLoaderData",
+ L"usable", // L"EfiBootServicesCode",
+ L"usable", // L"EfiBootServicesData",
+ L"reserved", // L"EfiRuntimeServicesCode",
+ L"reserved", // L"EfiRuntimeServicesData",
+ L"usable", // L"EfiConventionalMemory",
+ L"reserved", // L"EfiUnusableMemory",
+ L"ACPI data",// L"EfiACPIReclaimMemory",
+ L"ACPI NVS", // L"EfiACPIMemoryNVS",
+ L"reserved", // L"EfiMemoryMappedIO",
+ L"reserved", // L"EfiMemoryMappedIOPortSpace",
+ L"reserved", // L"EfiPalCode",
+ L"usable", // L"EfiPersistentMemory",
+ L"usable", // L"EfiMaxMemoryType"
+};
+
+
+const CHAR16 *
+memory_type_to_str(UINT32 type)
+{
+ if (type > sizeof(memory_types)/sizeof(CHAR16 *))
+ return L"Unknown";
+
+ return memory_types[type];
+}
+
+const CHAR16 *
+memory_type_to_str_OS_view(UINT32 type)
+{
+ if (type > sizeof(memory_types_OS_view)/sizeof(CHAR16 *))
+ return L"Unknown";
+
+ return memory_types_OS_view[type];
+}
+
+#define ATTRIBUTE_STR_SIZE 50
+
+#define CHECK_EFI_MEMORY_ATTRIBUTE(attr) if (attrs & EFI_MEMORY_##attr) { \
+ StrCpyS(&str[i], ATTRIBUTE_STR_SIZE, L" "#attr); \
+ i+=StrLen(L" "#attr); \
+ }
+
+const CHAR16 *
+memory_attrs_to_str(CHAR16* str, UINT64 attrs)
+{
+ int i=0;
+ SetMem((VOID *)str, sizeof(str), 0);
+
+ CHECK_EFI_MEMORY_ATTRIBUTE(UC)
+ CHECK_EFI_MEMORY_ATTRIBUTE(WC)
+ CHECK_EFI_MEMORY_ATTRIBUTE(WT)
+ CHECK_EFI_MEMORY_ATTRIBUTE(WB)
+ CHECK_EFI_MEMORY_ATTRIBUTE(UCE)
+ CHECK_EFI_MEMORY_ATTRIBUTE(WP)
+ CHECK_EFI_MEMORY_ATTRIBUTE(RP)
+ CHECK_EFI_MEMORY_ATTRIBUTE(XP)
+ CHECK_EFI_MEMORY_ATTRIBUTE(NV)
+ CHECK_EFI_MEMORY_ATTRIBUTE(MORE_RELIABLE)
+ CHECK_EFI_MEMORY_ATTRIBUTE(RO)
+ CHECK_EFI_MEMORY_ATTRIBUTE(SP)
+ CHECK_EFI_MEMORY_ATTRIBUTE(CPU_CRYPTO)
+ CHECK_EFI_MEMORY_ATTRIBUTE(RUNTIME)
+
+ return str;
+}
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ UINTN MemoryMapSize = 0;
+ EFI_MEMORY_DESCRIPTOR* MemoryMap = NULL;
+ UINTN MapKey;
+ UINTN DescriptorSize;
+ UINT32 DescriptorVersion;
+
+ EFI_STATUS Status;
+
+
+ EFI_SHELL_PARAMETERS_PROTOCOL* ShellParameters;
+
+ Status = gBS->HandleProtocol(
+ ImageHandle,
+ &gEfiShellParametersProtocolGuid,
+ (VOID **) &ShellParameters
+ );
+
+ BOOLEAN full=FALSE;
+ if (Status == EFI_SUCCESS) {
+ if (ShellParameters->Argc == 2) {
+ if (!StrCmp(ShellParameters->Argv[1], L"full")) {
+ full=TRUE;
+ }
+ }
+ }
+
+
+ Status = gBS->GetMemoryMap(
+ &MemoryMapSize,
+ MemoryMap,
+ &MapKey,
+ &DescriptorSize,
+ &DescriptorVersion
+ );
+
+ if (Status == EFI_BUFFER_TOO_SMALL) {
+ Status = gBS->AllocatePool(
+ EfiBootServicesData,
+ MemoryMapSize,
+ (void**)&MemoryMap
+ );
+
+ if (EFI_ERROR(Status)) {
+ Print(L"AllocatePool error: %r\n", Status);
+ return Status;
+ }
+
+ Status = gBS->GetMemoryMap(
+ &MemoryMapSize,
+ MemoryMap,
+ &MapKey,
+ &DescriptorSize,
+ &DescriptorVersion
+ );
+
+ if (!EFI_ERROR(Status))
+ {
+ EFI_MEMORY_DESCRIPTOR* desc = MemoryMap;
+ EFI_MEMORY_DESCRIPTOR* next_desc;
+ int i = 0;
+ while ((UINT8 *)desc < (UINT8 *)MemoryMap + MemoryMapSize) {
+ UINTN PAGE_SIZE = 4096;
+ UINTN mapping_size =(UINTN) desc->NumberOfPages * PAGE_SIZE;
+
+ UINT64 Start = desc->PhysicalStart;
+
+ next_desc = (EFI_MEMORY_DESCRIPTOR *)((UINT8 *)desc + DescriptorSize);
+ if (!full) {
+ while ((UINT8 *)next_desc < (UINT8 *)MemoryMap + MemoryMapSize) {
+ mapping_size =(UINTN) desc->NumberOfPages * PAGE_SIZE;
+ if ((desc->PhysicalStart + mapping_size) == (next_desc->PhysicalStart)) {
+
+ if (desc->Type != next_desc->Type) {
+ if (StrCmp(memory_type_to_str_OS_view(desc->Type),
+ memory_type_to_str_OS_view(next_desc->Type)))
+ break;
+ }
+
+ desc=next_desc;
+ next_desc = (EFI_MEMORY_DESCRIPTOR *)((UINT8 *)next_desc + DescriptorSize);
+ } else {
+ break;
+ }
+ }
+ }
+
+ if (full) {
+ CHAR16 str[ATTRIBUTE_STR_SIZE];
+ Print(L"[#%02d] Type: %s Attr: %s\n", i++,
+ memory_type_to_str(desc->Type), memory_attrs_to_str(str, desc->Attribute));
+ Print(L" Phys: %016llx-%016llx\n", Start, Start + mapping_size - 1);
+ }
+ else {
+ Print(L" [mem: %016llx-%016llx] %s\n", Start, desc->PhysicalStart + mapping_size - 1,
+ memory_type_to_str_OS_view(desc->Type) );
+ }
+
+ desc = next_desc;
+ }
+
+ gBS->FreePool(MemoryMap);
+ } else {
+ Print(L"GetMemoryMap with buffer error: %r\n", Status);
+ }
+ } else {
+ Print(L"GetMemoryMap without buffer error: %r\n", Status);
+ }
+
+ return Status;
+}
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.inf b/Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.inf
new file mode 100644
index 0000000..777010d
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/MemoryInfo/MemoryInfo.inf
@@ -0,0 +1,21 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = MemoryInfo
+ FILE_GUID = d2ce1d65-603e-4b48-b3e1-fe65d5d0bca8
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ MemoryInfo.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+
+[Protocols]
+ gEfiShellParametersProtocolGuid
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.c b/Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.c
new file mode 100644
index 0000000..7ed3081
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.c
@@ -0,0 +1,15 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Library/PcdLib.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ Print(L"PcdMyVar32=%d\n", FixedPcdGet32(PcdMyVar32));
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.inf b/Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.inf
new file mode 100644
index 0000000..11dafe9
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/PCDLesson/PCDLesson.inf
@@ -0,0 +1,22 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = PCDLesson
+ FILE_GUID = 8c1a6b71-0c4b-4497-aaad-07404edf142c
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ PCDLesson.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+ UefiLessonsPkg/UefiLessonsPkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+
+[FixedPcd]
+ gUefiLessonsPkgTokenSpaceGuid.PcdMyVar32
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.c b/Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.c
new file mode 100644
index 0000000..7f6b58c
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.c
@@ -0,0 +1,93 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+#include <Library/DevicePathLib.h>
+#include <Library/PrintLib.h>
+
+
+EFI_STATUS
+GetNvramVariable( CHAR16 *VariableName,
+ EFI_GUID *VariableOwnerGuid,
+ VOID **Buffer,
+ UINTN *BufferSize)
+{
+ UINTN Size = 0;
+ *BufferSize = 0;
+
+ EFI_STATUS Status = gRT->GetVariable(VariableName, VariableOwnerGuid, NULL, &Size, NULL);
+ if (Status != EFI_BUFFER_TOO_SMALL) {
+ Print(L"Error! 'gRT->GetVariable' call returned %r\n", Status);
+ return Status;
+ }
+
+ *Buffer = AllocateZeroPool(Size);
+ if (!Buffer) {
+ Print(L"Error! 'AllocateZeroPool' call returned %r\n", Status);
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ Status = gRT->GetVariable(VariableName, VariableOwnerGuid, NULL, &Size, *Buffer);
+ if (Status == EFI_SUCCESS) {
+ *BufferSize = Size;
+ } else {
+ FreePool( *Buffer );
+ *Buffer = NULL;
+ }
+
+ return Status;
+}
+
+
+VOID PrintBootOption(CHAR16* BootOptionName)
+{
+ UINTN OptionSize;
+ UINT8* Buffer;
+
+ EFI_STATUS Status = GetNvramVariable(BootOptionName, &gEfiGlobalVariableGuid, (VOID**)&Buffer, &OptionSize);
+ if (Status == EFI_SUCCESS) {
+ EFI_LOAD_OPTION* LoadOption = (EFI_LOAD_OPTION*) Buffer;
+ CHAR16* Description = (CHAR16*)(Buffer + sizeof (EFI_LOAD_OPTION));
+ UINTN DescriptionSize = StrSize(Description);
+
+ Print(L"%s\n", Description);
+ if (LoadOption->FilePathListLength != 0) {
+ VOID* FilePathList = (UINT8 *)Description + DescriptionSize;
+ CHAR16* DevPathString = ConvertDevicePathToText(FilePathList, TRUE, FALSE);
+ Print(L"%s\n", DevPathString);
+ }
+ } else {
+ Print(L"Can't get %s variable\n", BootOptionName);
+ }
+}
+
+
+INTN EFIAPI ShellAppMain(IN UINTN Argc, IN CHAR16 **Argv)
+{
+ UINTN OptionSize;
+ EFI_STATUS Status;
+
+ UINT16* BootCurrent;
+ Status = GetNvramVariable(L"BootCurrent", &gEfiGlobalVariableGuid, (VOID**)&BootCurrent, &OptionSize);
+ if (Status != EFI_SUCCESS) {
+ Print(L"Can't get BootCurrent variable\n");
+ }
+
+ UINT16* BootOrderArray;
+ Status = GetNvramVariable(L"BootOrder", &gEfiGlobalVariableGuid, (VOID**)&BootOrderArray, &OptionSize);
+ if (Status == EFI_SUCCESS) {
+ for (UINTN i=0; i<(OptionSize/sizeof(UINT16)); i++) {
+ CHAR16 BootOptionStr[sizeof("Boot####")+1];
+ UnicodeSPrint(BootOptionStr, (sizeof("Boot####")+1)*sizeof(CHAR16), L"Boot%04x", BootOrderArray[i]);
+ Print(L"%s%s\n", BootOptionStr, (BootOrderArray[i] == *BootCurrent)? L"*" : L"" );
+ PrintBootOption(BootOptionStr);
+ Print(L"\n");
+ }
+ } else {
+ Print(L"Can't get BootOrder variable\n");
+ }
+
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.inf b/Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.inf
new file mode 100644
index 0000000..d2cfba9
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/ShowBootVariables/ShowBootVariables.inf
@@ -0,0 +1,19 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = ShowBootVariables
+ FILE_GUID = 31266d12-9c60-478e-905e-05d117a3a9df
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = ShellCEntryLib
+
+[Sources]
+ ShowBootVariables.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+ ShellCEntryLib
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.c b/Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.c
new file mode 100644
index 0000000..b13aa6c
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.c
@@ -0,0 +1,14 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+INTN EFIAPI ShellAppMain(IN UINTN Argc, IN CHAR16 **Argv)
+{
+// SystemTable->ConOut->OutputString(SystemTable->ConOut, L"Hello World!\n");
+ gST->ConOut->OutputString(gST->ConOut, L"Hello again!\n");
+ Print(L"Bye!\n");
+
+ for (UINTN i=Argc; i>0; i--) {
+ Print(L"Arg[%d]=%s\n", Argc-i, Argv[Argc-i]);
+ }
+ return 0;
+}
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.inf b/Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.inf
new file mode 100644
index 0000000..013bf4e
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/SimpleShellApp/SimpleShellApp.inf
@@ -0,0 +1,19 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = SimpleShellApp
+ FILE_GUID = 2afd1202-545e-4f8d-b8fb-bc179e84ddc8
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = ShellCEntryLib
+
+[Sources]
+ SimpleShellApp.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+ ShellCEntryLib
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.c b/Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.c
new file mode 100644
index 0000000..8bdf500
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.c
@@ -0,0 +1,10 @@
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ return EFI_SUCCESS;
+}
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.inf b/Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.inf
new file mode 100644
index 0000000..7d4bae2
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/SimplestApp/SimplestApp.inf
@@ -0,0 +1,16 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = SimplestApp
+ FILE_GUID = 4a298956-fbe0-47fb-ae3a-2d5a0a959a26
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ SimplestApp.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dec b/Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dec
new file mode 100644
index 0000000..94a42ff
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dec
@@ -0,0 +1,20 @@
+[Defines]
+ DEC_SPECIFICATION = 0x00010005
+ PACKAGE_NAME = UefiLessonsPkg
+ PACKAGE_GUID = 7e7edbba-ca2c-4177-a3f0-d3371358773a
+ PACKAGE_VERSION = 1.01
+
+[Includes]
+
+[LibraryClasses]
+
+[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
+
diff --git a/Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dsc b/Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dsc
new file mode 100644
index 0000000..c4adde7
--- /dev/null
+++ b/Lessons/Lesson_20/UefiLessonsPkg/UefiLessonsPkg.dsc
@@ -0,0 +1,39 @@
+[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
+ 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
+
+[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/PCDLesson/PCDLesson.inf
+
+