Move lessons to separate folder

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

14 files changed, 771 insertions, 0 deletions

diff --git a/Lessons/Lesson_12/Conf/target.txt b/Lessons/Lesson_12/Conf/target.txt
new file mode 100644
index 0000000..c109dcf
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/README.md b/Lessons/Lesson_12/README.md
new file mode 100644
index 0000000..727d300
--- /dev/null
+++ b/Lessons/Lesson_12/README.md
@@ -0,0 +1,247 @@
+Let's investigate final protocol that was attached to our `ImageHandle` - `EFI_SHELL_PARAMETERS_PROTOCOL`
+
+https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Protocol/ShellParameters.h
+```
+typedef struct _EFI_SHELL_PARAMETERS_PROTOCOL {
+  ///
+  /// Points to an Argc-element array of points to NULL-terminated strings containing
+  /// the command-line parameters. The first entry in the array is always the full file
+  /// path of the executable. Any quotation marks that were used to preserve
+  /// whitespace have been removed.
+  ///
+  CHAR16 **Argv;
+
+  ///
+  /// The number of elements in the Argv array.
+  ///
+  UINTN Argc;
+
+  ///
+  /// The file handle for the standard input for this executable. This may be different
+  /// from the ConInHandle in EFI_SYSTEM_TABLE.
+  ///
+  SHELL_FILE_HANDLE StdIn;
+
+  ///
+  /// The file handle for the standard output for this executable. This may be different
+  /// from the ConOutHandle in EFI_SYSTEM_TABLE.
+  ///
+  SHELL_FILE_HANDLE StdOut;
+
+  ///
+  /// The file handle for the standard error output for this executable. This may be
+  /// different from the StdErrHandle in EFI_SYSTEM_TABLE.
+  ///
+  SHELL_FILE_HANDLE StdErr;
+} EFI_SHELL_PARAMETERS_PROTOCOL;
+```
+
+As we see, we can access command line arguments that was passed to our program through this protocol.
+Let's use it in our `MemoryInfo` program.
+
+In the last lesson we've printed our EFI memory map. It had >100 entries.
+When you boot Linux kernel, you can see some info about the current memory map, but this table is much shorter. It happens because of two facts:
+- Kernel differentiate EFI memory types much less granular. Instead of `EfiReservedMemoryType`/`EfiLoaderCode`/`EfiLoaderData`/...` it simply has only 4 types: `usable`/`ACPI NVS`/`ACPI data`/`reserved`
+- Kernel glues adjacent regions together
+
+
+I've generated kernel image for EFI x86-64 with buildroot:
+```
+cd ~
+git clone https://github.com/buildroot/buildroot.git
+cd buildroot
+make pc_x86_64_efi_defconfig
+make
+```
+
+If we try to boot this kernel with:
+```
+qemu-system-x86_64 -drive if=pflash,format=raw,file=Build/OvmfX64/RELEASE_GCC5/FV/OVMF.fd
+                   -drive format=raw,file=fat:rw:~/UEFI_disk
+                   -nographic
+                   -kernel ~/buildroot/output/images/bzImage
+                   -append "console=ttyS0"
+```
+
+In kernel boot log we can see:
+```
+BIOS-provided physical RAM map:
+BIOS-e820: [mem 0x0000000000000000-0x000000000009ffff] usable
+BIOS-e820: [mem 0x0000000000100000-0x00000000007fffff] usable
+BIOS-e820: [mem 0x0000000000800000-0x0000000000807fff] ACPI NVS
+BIOS-e820: [mem 0x0000000000808000-0x000000000080ffff] usable
+BIOS-e820: [mem 0x0000000000810000-0x00000000008fffff] ACPI NVS
+BIOS-e820: [mem 0x0000000000900000-0x00000000078eefff] usable
+BIOS-e820: [mem 0x00000000078ef000-0x0000000007b6efff] reserved
+BIOS-e820: [mem 0x0000000007b6f000-0x0000000007b7efff] ACPI data
+BIOS-e820: [mem 0x0000000007b7f000-0x0000000007bfefff] ACPI NVS
+BIOS-e820: [mem 0x0000000007bff000-0x0000000007ef3fff] usable
+BIOS-e820: [mem 0x0000000007ef4000-0x0000000007f77fff] reserved
+BIOS-e820: [mem 0x0000000007f78000-0x0000000007ffffff] ACPI NVS
+BIOS-e820: [mem 0x00000000ffc00000-0x00000000ffffffff] reserved
+```
+
+Let's modify our `MemoryInfo` program:
+- if `full` option is passed, we print memory map as we do now
+- if no option is passed, we print memory map in a "Linux kernel way"
+
+First, add `full` boolean flag. If argument "full" is passed to our program, we'll set this flag, else it would be equal to `false`.
+```
+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;
+    }
+  }
+}
+```
+
+To use `EFI_SHELL_PARAMETERS_PROTOCOL` we need to add include file:
+```
+#include <Protocol/ShellParameters.h>
+```
+And add GUID to the application *.inf file:
+```
+[Protocols]
+  gEfiShellParametersProtocolGuid
+```
+
+Now to the next problem. Create a function for OS memory type mapping:
+```
+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_OS_view(UINT32 type)
+{
+    if (type > sizeof(memory_types_OS_view)/sizeof(CHAR16 *))
+        return L"Unknown";
+
+    return memory_types_OS_view[type];
+}
+```
+
+And finally we need to modify our program to glue adjacent regions with the same type together if the `full` flag is not set:
+```
+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;
+}
+```
+
+Build program and copy it to UEFI folder.
+If we run in with the `full` option, everything would be like the last time:
+```
+FS0:\> MemoryInfo.efi full
+[#00] Type: EfiBootServicesCode  Attr:  UC WC WT WB
+      Phys: 0000000000000000-0000000000000FFF
+[#01] Type: EfiConventionalMemory  Attr:  UC WC WT WB
+      Phys: 0000000000001000-000000000009FFFF
+[#02] Type: EfiConventionalMemory  Attr:  UC WC WT WB
+      Phys: 0000000000100000-00000000007FFFFF
+[#03] Type: EfiACPIMemoryNVS  Attr:  UC WC WT WB
+      Phys: 0000000000800000-0000000000807FFF
+[#04] Type: EfiConventionalMemory  Attr:  UC WC WT WB
+      Phys: 0000000000808000-000000000080FFFF
+[#05] Type: EfiACPIMemoryNVS  Attr:  UC WC WT WB
+      Phys: 0000000000810000-00000000008FFFFF
+...
+```
+
+But if we run it without the `full` option, we will get a map similar to the that kernel displays in its boot log:
+```
+FS0:\> MemoryInfo.efi
+ [mem: 0000000000000000-000000000009FFFF] usable
+ [mem: 0000000000100000-00000000007FFFFF] usable
+ [mem: 0000000000800000-0000000000807FFF] ACPI NVS
+ [mem: 0000000000808000-000000000080FFFF] usable
+ [mem: 0000000000810000-00000000008FFFFF] ACPI NVS
+ [mem: 0000000000900000-00000000078EEFFF] usable
+ [mem: 00000000078EF000-0000000007B6EFFF] reserved
+ [mem: 0000000007B6F000-0000000007B7EFFF] ACPI data
+ [mem: 0000000007B7F000-0000000007BFEFFF] ACPI NVS
+ [mem: 0000000007BFF000-0000000007EF3FFF] usable
+ [mem: 0000000007EF4000-0000000007F77FFF] reserved
+ [mem: 0000000007F78000-0000000007FFFFFF] ACPI NVS
+ [mem: 00000000FFC00000-00000000FFFFFFFF] reserved
+```
+Compare it with the actual kernel output:
+```
+BIOS-provided physical RAM map:
+BIOS-e820: [mem 0x0000000000000000-0x000000000009ffff] usable
+BIOS-e820: [mem 0x0000000000100000-0x00000000007fffff] usable
+BIOS-e820: [mem 0x0000000000800000-0x0000000000807fff] ACPI NVS
+BIOS-e820: [mem 0x0000000000808000-0x000000000080ffff] usable
+BIOS-e820: [mem 0x0000000000810000-0x00000000008fffff] ACPI NVS
+BIOS-e820: [mem 0x0000000000900000-0x00000000078eefff] usable
+BIOS-e820: [mem 0x00000000078ef000-0x0000000007b6efff] reserved
+BIOS-e820: [mem 0x0000000007b6f000-0x0000000007b7efff] ACPI data
+BIOS-e820: [mem 0x0000000007b7f000-0x0000000007bfefff] ACPI NVS
+BIOS-e820: [mem 0x0000000007bff000-0x0000000007ef3fff] usable
+BIOS-e820: [mem 0x0000000007ef4000-0x0000000007f77fff] reserved
+BIOS-e820: [mem 0x0000000007f78000-0x0000000007ffffff] ACPI NVS
+BIOS-e820: [mem 0x00000000ffc00000-0x00000000ffffffff] reserved
+```
diff --git a/Lessons/Lesson_12/UefiLessonsPkg/HelloWorld/HelloWorld.c b/Lessons/Lesson_12/UefiLessonsPkg/HelloWorld/HelloWorld.c
new file mode 100644
index 0000000..1f05899
--- /dev/null
+++ b/Lessons/Lesson_12/UefiLessonsPkg/HelloWorld/HelloWorld.c
@@ -0,0 +1,15 @@
+#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");
+  return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_12/UefiLessonsPkg/HelloWorld/HelloWorld.inf b/Lessons/Lesson_12/UefiLessonsPkg/HelloWorld/HelloWorld.inf
new file mode 100644
index 0000000..d65ca2e
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/ImageHandle/ImageHandle.c b/Lessons/Lesson_12/UefiLessonsPkg/ImageHandle/ImageHandle.c
new file mode 100644
index 0000000..32e9c43
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/ImageHandle/ImageHandle.inf b/Lessons/Lesson_12/UefiLessonsPkg/ImageHandle/ImageHandle.inf
new file mode 100644
index 0000000..34256ee
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/ImageInfo/ImageInfo.c b/Lessons/Lesson_12/UefiLessonsPkg/ImageInfo/ImageInfo.c
new file mode 100644
index 0000000..c45570e
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/ImageInfo/ImageInfo.inf b/Lessons/Lesson_12/UefiLessonsPkg/ImageInfo/ImageInfo.inf
new file mode 100644
index 0000000..0ce54a6
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/MemoryInfo/MemoryInfo.c b/Lessons/Lesson_12/UefiLessonsPkg/MemoryInfo/MemoryInfo.c
new file mode 100644
index 0000000..8c3bcf2
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/MemoryInfo/MemoryInfo.inf b/Lessons/Lesson_12/UefiLessonsPkg/MemoryInfo/MemoryInfo.inf
new file mode 100644
index 0000000..777010d
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/SimplestApp/SimplestApp.c b/Lessons/Lesson_12/UefiLessonsPkg/SimplestApp/SimplestApp.c
new file mode 100644
index 0000000..8bdf500
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/SimplestApp/SimplestApp.inf b/Lessons/Lesson_12/UefiLessonsPkg/SimplestApp/SimplestApp.inf
new file mode 100644
index 0000000..7d4bae2
--- /dev/null
+++ b/Lessons/Lesson_12/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_12/UefiLessonsPkg/UefiLessonsPkg.dsc b/Lessons/Lesson_12/UefiLessonsPkg/UefiLessonsPkg.dsc
new file mode 100644
index 0000000..09f38ea
--- /dev/null
+++ b/Lessons/Lesson_12/UefiLessonsPkg/UefiLessonsPkg.dsc
@@ -0,0 +1,33 @@
+[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
+
+[Components]
+  UefiLessonsPkg/SimplestApp/SimplestApp.inf
+  UefiLessonsPkg/HelloWorld/HelloWorld.inf
+  UefiLessonsPkg/ImageHandle/ImageHandle.inf
+  UefiLessonsPkg/ImageInfo/ImageInfo.inf
+  UefiLessonsPkg/MemoryInfo/MemoryInfo.inf
+
+
diff --git a/Lessons/Lesson_12/bzImage b/Lessons/Lesson_12/bzImage
new file mode 100644
index 0000000..80c73e2
--- /dev/null
+++ b/Lessons/Lesson_12/bzImage