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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
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Move lessons to separate folder
Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Diffstat (limited to 'Lessons/Lesson_28')
-rw-r--r--Lessons/Lesson_28/README.md551
-rw-r--r--Lessons/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c106
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+The latest ACPI specification can be found under UEFI specifications page https://uefi.org/specifications
+
+The current latest specification is "ACPI Specification Version 6.4 (released January 2021)" (https://uefi.org/specs/ACPI/6.4/)
+
+
+Use the same tactic we used for SMBIOS tables to print ACPI entry point table address:
+```
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Library/BaseMemoryLib.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ for (UINTN i=0; i<SystemTable->NumberOfTableEntries; i++) {
+ if (CompareGuid(&(SystemTable->ConfigurationTable[i].VendorGuid), &gEfiAcpi20TableGuid)) {
+ Print(L"ACPI table is placed at %p\n\n", SystemTable->ConfigurationTable[i].VendorTable);
+ }
+ }
+ return EFI_SUCCESS;
+}
+```
+
+Use `dmem` to peak inside ACPI table memory:
+```
+FS0:\> AcpiInfo.efi
+ACPI table is placed at 7B7E014
+
+FS0:\> dmem 7B7E014 30
+Memory Address 0000000007B7E014 30 Bytes
+ 07B7E014: 52 53 44 20 50 54 52 20-4E 42 4F 43 48 53 20 02 *RSD PTR NBOCHS .*
+ 07B7E024: 74 D0 B7 07 24 00 00 00-E8 D0 B7 07 00 00 00 00 *t...$...........*
+ 07B7E034: 66 00 00 00 AF AF AF AF-AF AF AF AF AF AF AF AF *f...............*
+FS0:\>
+```
+
+The signature `RSP PTR` stands for `Root System Description Pointer (RSDP) Structure` (https://uefi.org/specs/ACPI/6.4/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#root-system-description-pointer-rsdp-structure).
+
+It contains addresses for `RSDT` and `XSDT` tables. If you calculate offsets, you'll get these addresses from our memory dump:
+```
+XSDT=0x07B7D0E8
+RSDT=0x07B7D074
+```
+These tables in turn would cointain pointers to other ACPI tables that actualy contain data useful to OS.
+
+According to the spec "platforms provide the RSDT to enable compatibility with ACPI 1.0 operating systems. The XSDT supersedes RSDT functionality". So if you peak these addresses with `dmem`, table contents would be pretty much the same except table signatures. Therefore in our app code we would be parsing XSDT table data.
+
+Ok, it's time to write some code. ACPI structures are defined in the following header files:
+```
+$ ls -1 MdePkg/Include/IndustryStandard/Acpi*
+MdePkg/Include/IndustryStandard/Acpi.h
+MdePkg/Include/IndustryStandard/Acpi10.h
+MdePkg/Include/IndustryStandard/Acpi20.h
+MdePkg/Include/IndustryStandard/Acpi30.h
+MdePkg/Include/IndustryStandard/Acpi40.h
+MdePkg/Include/IndustryStandard/Acpi50.h
+MdePkg/Include/IndustryStandard/Acpi51.h
+MdePkg/Include/IndustryStandard/Acpi60.h
+MdePkg/Include/IndustryStandard/Acpi61.h
+MdePkg/Include/IndustryStandard/Acpi62.h
+MdePkg/Include/IndustryStandard/Acpi63.h
+MdePkg/Include/IndustryStandard/AcpiAml.h
+```
+
+Keep in mind that headers for latter standards include headers for earlier standards in itself.
+```
+Acpi.h > Acpi63.h > Acpi62.h > ... > Acpi10.h > AcpiAml.h
+```
+
+Let's look at RSDP structure definition at the most latest ACPI standard header file
+https://github.com/tianocore/edk2/blob/master/MdePkg/Include/IndustryStandard/Acpi63.h
+```
+///
+/// Root System Description Pointer Structure
+///
+typedef struct {
+ UINT64 Signature;
+ UINT8 Checksum;
+ UINT8 OemId[6];
+ UINT8 Revision;
+ UINT32 RsdtAddress;
+ UINT32 Length;
+ UINT64 XsdtAddress;
+ UINT8 ExtendedChecksum;
+ UINT8 Reserved[3];
+} EFI_ACPI_6_3_ROOT_SYSTEM_DESCRIPTION_POINTER;
+```
+
+We can use it to print addresses of RSDT/XSDT tables.
+```
+EFI_ACPI_6_3_ROOT_SYSTEM_DESCRIPTION_POINTER* RSDP = NULL;
+
+for (UINTN i=0; i<SystemTable->NumberOfTableEntries; i++) {
+ if (CompareGuid(&(SystemTable->ConfigurationTable[i].VendorGuid), &gEfiAcpi20TableGuid)) {
+ Print(L"RSDP table is placed at %p\n\n", SystemTable->ConfigurationTable[i].VendorTable);
+ RSDP = SystemTable->ConfigurationTable[i].VendorTable;
+ }
+}
+
+if (!RSDP) {
+ Print(L"No ACPI2.0 table was found in the system\n");
+ return EFI_SUCCESS;
+}
+
+if (((CHAR8)((RSDP->Signature >> 0) & 0xFF) != 'R') ||
+ ((CHAR8)((RSDP->Signature >> 8) & 0xFF) != 'S') ||
+ ((CHAR8)((RSDP->Signature >> 16) & 0xFF) != 'D') ||
+ ((CHAR8)((RSDP->Signature >> 24) & 0xFF) != ' ') ||
+ ((CHAR8)((RSDP->Signature >> 32) & 0xFF) != 'P') ||
+ ((CHAR8)((RSDP->Signature >> 40) & 0xFF) != 'T') ||
+ ((CHAR8)((RSDP->Signature >> 48) & 0xFF) != 'R') ||
+ ((CHAR8)((RSDP->Signature >> 56) & 0xFF) != ' ')) {
+ Print(L"Error! RSDP signature is not valid!\n");
+ return EFI_SUCCESS;
+}
+
+Print(L"System description tables:\n");
+Print(L"\tRSDT table is placed at address %p\n", RSDP->RsdtAddress);
+Print(L"\tXSDT table is placed at address %p\n", RSDP->XsdtAddress);
+Print(L"\n");
+```
+
+In the same file (https://github.com/tianocore/edk2/blob/master/MdePkg/Include/IndustryStandard/Acpi63.h) you can find description for XSDT structure:
+```
+//
+// Extended System Description Table
+// No definition needed as it is a common description table header, the same with
+// EFI_ACPI_DESCRIPTION_HEADER, followed by a variable number of UINT64 table pointers.
+//
+```
+
+The definition for `EFI_ACPI_DESCRIPTION_HEADER` can be found here https://github.com/tianocore/edk2/blob/master/MdePkg/Include/IndustryStandard/Acpi10.h:
+```
+#pragma pack(1)
+///
+/// The common ACPI description table header. This structure prefaces most ACPI tables.
+///
+typedef struct {
+ UINT32 Signature;
+ UINT32 Length;
+ UINT8 Revision;
+ UINT8 Checksum;
+ UINT8 OemId[6];
+ UINT64 OemTableId;
+ UINT32 OemRevision;
+ UINT32 CreatorId;
+ UINT32 CreatorRevision;
+} EFI_ACPI_DESCRIPTION_HEADER;
+#pragma pack()
+```
+
+Let's check information about other ACPI tables that are present in the system:
+```
+EFI_ACPI_DESCRIPTION_HEADER* XSDT = (EFI_ACPI_DESCRIPTION_HEADER*)RSDP->XsdtAddress;
+if (((CHAR8)((XSDT->Signature >> 0) & 0xFF) != 'X') ||
+ ((CHAR8)((XSDT->Signature >> 8) & 0xFF) != 'S') ||
+ ((CHAR8)((XSDT->Signature >> 16) & 0xFF) != 'D') ||
+ ((CHAR8)((XSDT->Signature >> 24) & 0xFF) != 'T')) {
+ Print(L"Error! XSDT signature is not valid!\n");
+ return EFI_SUCCESS;
+}
+
+Print(L"Main ACPI tables:\n");
+UINT64 offset = sizeof(EFI_ACPI_DESCRIPTION_HEADER);
+while (offset < XSDT->Length) {
+ UINT64* table_address = (UINT64*)((UINT8*)XSDT + offset);
+ EFI_ACPI_6_3_COMMON_HEADER* table = (EFI_ACPI_6_3_COMMON_HEADER*)(*table_address);
+ TableName[0] = (CHAR16)((table->Signature>> 0)&0xFF);
+ TableName[1] = (CHAR16)((table->Signature>> 8)&0xFF);
+ TableName[2] = (CHAR16)((table->Signature>>16)&0xFF);
+ TableName[3] = (CHAR16)((table->Signature>>24)&0xFF);
+ TableName[4] = 0;
+
+ Print(L"\t%s table is placed at address %p with length 0x%x\n",
+ TableName,
+ table,
+ table->Length);
+ offset += sizeof(UINT64);
+}
+```
+
+If you build our app and execute it under OVMF now you would get:
+```
+FS0:\> AcpiInfo.efi
+RSDP table is placed at 7B7E014
+
+System description tables:
+ RSDT table is placed at address 7B7D074
+ XSDT table is placed at address 7B7D0E8
+
+Main ACPI tables:
+ FACP table is placed at address 7B7A000 with length 0x74
+ APIC table is placed at address 7B79000 with length 0x78
+ HPET table is placed at address 7B78000 with length 0x38
+ BGRT table is placed at address 7B77000 with length 0x38
+```
+
+Pretty neat, our system has 4 ACPI data tables:
+- Fixed ACPI Description Table (`FACP`) - https://uefi.org/specs/ACPI/6.4/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#fixed-acpi-description-table-fadt
+- Multiple APIC Description Table (`MADT`) - https://uefi.org/specs/ACPI/6.4/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#multiple-apic-description-table-madt
+- IA-PC High Precision Event Timer Table (`HPET`) - http://www.intel.com/content/dam/www/public/us/en/documents/technical-specifications/software-developers-hpet-spec-1-0a.pdf - This one is not present in ACPI spec, but in a separate document from the page https://uefi.org/acpi
+- Boot Graphics Resource Table (`BGRT`) - https://uefi.org/specs/ACPI/6.4/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#boot-graphics-resource-table-bgrt
+
+
+Keep in mind that as with SMBIOS tables we could use a protocol to get the same data. `GetAcpiTable()` function of a `EFI_ACPI_SDT_PROTOCOL` can help to get the same information. This protocol also is defined by UEFI PI specification.
+
+In edk2 it is defined under https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Protocol/AcpiSystemDescriptionTable.h
+
+# Use `EFI_SHELL_PROTOCOL` to save table data
+
+Now let's try to save ACPI tables from memory to files.
+
+To do this we can utilize `EFI_SHELL_PROTOCOL` that is defined in UEFI Shell specification (https://uefi.org/sites/default/files/resources/UEFI_Shell_2_2.pdf). It has many functions for File I/O.
+
+The necessary header in edk2 is https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Protocol/Shell.h
+```
+typedef struct _EFI_SHELL_PROTOCOL {
+ EFI_SHELL_EXECUTE Execute;
+ EFI_SHELL_GET_ENV GetEnv;
+ EFI_SHELL_SET_ENV SetEnv;
+ EFI_SHELL_GET_ALIAS GetAlias;
+ EFI_SHELL_SET_ALIAS SetAlias;
+ EFI_SHELL_GET_HELP_TEXT GetHelpText;
+ EFI_SHELL_GET_DEVICE_PATH_FROM_MAP GetDevicePathFromMap;
+ EFI_SHELL_GET_MAP_FROM_DEVICE_PATH GetMapFromDevicePath;
+ EFI_SHELL_GET_DEVICE_PATH_FROM_FILE_PATH GetDevicePathFromFilePath;
+ EFI_SHELL_GET_FILE_PATH_FROM_DEVICE_PATH GetFilePathFromDevicePath;
+ EFI_SHELL_SET_MAP SetMap;
+ EFI_SHELL_GET_CUR_DIR GetCurDir;
+ EFI_SHELL_SET_CUR_DIR SetCurDir;
+ EFI_SHELL_OPEN_FILE_LIST OpenFileList;
+ EFI_SHELL_FREE_FILE_LIST FreeFileList;
+ EFI_SHELL_REMOVE_DUP_IN_FILE_LIST RemoveDupInFileList;
+ EFI_SHELL_BATCH_IS_ACTIVE BatchIsActive;
+ EFI_SHELL_IS_ROOT_SHELL IsRootShell;
+ EFI_SHELL_ENABLE_PAGE_BREAK EnablePageBreak;
+ EFI_SHELL_DISABLE_PAGE_BREAK DisablePageBreak;
+ EFI_SHELL_GET_PAGE_BREAK GetPageBreak;
+ EFI_SHELL_GET_DEVICE_NAME GetDeviceName;
+ EFI_SHELL_GET_FILE_INFO GetFileInfo;
+ EFI_SHELL_SET_FILE_INFO SetFileInfo;
+ EFI_SHELL_OPEN_FILE_BY_NAME OpenFileByName;
+ EFI_SHELL_CLOSE_FILE CloseFile;
+ EFI_SHELL_CREATE_FILE CreateFile;
+ EFI_SHELL_READ_FILE ReadFile;
+ EFI_SHELL_WRITE_FILE WriteFile;
+ EFI_SHELL_DELETE_FILE DeleteFile;
+ EFI_SHELL_DELETE_FILE_BY_NAME DeleteFileByName;
+ EFI_SHELL_GET_FILE_POSITION GetFilePosition;
+ EFI_SHELL_SET_FILE_POSITION SetFilePosition;
+ EFI_SHELL_FLUSH_FILE FlushFile;
+ EFI_SHELL_FIND_FILES FindFiles;
+ EFI_SHELL_FIND_FILES_IN_DIR FindFilesInDir;
+ EFI_SHELL_GET_FILE_SIZE GetFileSize;
+ EFI_SHELL_OPEN_ROOT OpenRoot;
+ EFI_SHELL_OPEN_ROOT_BY_HANDLE OpenRootByHandle;
+ EFI_EVENT ExecutionBreak;
+ UINT32 MajorVersion;
+ UINT32 MinorVersion;
+ // Added for Shell 2.1
+ EFI_SHELL_REGISTER_GUID_NAME RegisterGuidName;
+ EFI_SHELL_GET_GUID_NAME GetGuidName;
+ EFI_SHELL_GET_GUID_FROM_NAME GetGuidFromName;
+ EFI_SHELL_GET_ENV_EX GetEnvEx;
+} EFI_SHELL_PROTOCOL;
+```
+
+We will use 3 functions from this protocol `OpenFileByName`/`WriteFile`/`CloseFile`:
+```
+EFI_SHELL_PROTOCOL.OpenFileByName()
+
+Summary:
+Opens a file or a directory by file name.
+
+Prototype:
+typdef
+EFI_STATUS
+(EFIAPI *EFI_SHELL_OPEN_FILE_BY_NAME) (
+ IN CONST CHAR16 *FileName,
+ OUT SHELL_FILE_HANDLE *FileHandle,
+ IN UINT64 OpenMode
+ );
+
+Parameters:
+FileName Points to the null-terminated UCS-2 encoded file name.
+FileHandle On return, points to the file handle.
+OpenMode File open mode.
+
+Description:
+This function opens the specified file in the specified OpenMode and returns a file handle.
+```
+```
+EFI_SHELL_PROTOCOL.WriteFile()
+
+Summary:
+Writes data to the file.
+
+Prototype:
+typedef
+EFI_STATUS
+(EFIAPI EFI_SHELL_WRITE_FILE)(
+ IN SHELL_FILE_HANDLE FileHandle,
+ IN OUT UINTN *BufferSize,
+ OUT VOID *Buffer
+ );
+
+Parameters:
+FileHandle The opened file handle for writing.
+BufferSize On input, size of Buffer.
+Buffer The buffer in which data to write.
+
+Description:
+This function writes the specified number of bytes to the file at the current file position. The current file position is advanced the actual number of bytes
+written, which is returned in BufferSize. Partial writes only occur when there has been a data error during the write attempt (such as “volume space full”).
+The file automatically grows to hold the data, if required.
+```
+```
+EFI_SHELL_PROTOCOL.CloseFile()
+
+Summary:
+Closes the file handle.
+
+Prototype:
+typedef
+EFI_STATUS
+(EFIAPI *EFI_SHELL_CLOSE_FILE)(
+ IN SHELL_FILE_HANDLE FileHandle
+ );
+
+Parameters:
+FileHandle The file handle to be closed
+Description This function closes a specified file handle. All “dirty” cached file data is flushed
+ to the device, and the file is closed. In all cases, the handle is closed.
+
+```
+
+Now let's start coding. Add necessary include to our *.c file:
+```
+#include <Protocol/Shell.h>
+```
+And necessary protocol guid to our *.inf file:
+```
+[Protocols]
+ gEfiShellProtocolGuid
+```
+
+In our program we need to acquire `EFI_SHELL_PROTOCOL`, this can be done via `LocateProtocol` function from the BootServices:
+```
+EFI_SHELL_PROTOCOL* ShellProtocol;
+EFI_STATUS Status = gBS->LocateProtocol(
+ &gEfiShellProtocolGuid,
+ NULL,
+ (VOID **)&ShellProtocol
+);
+
+if (EFI_ERROR(Status)) {
+ Print(L"Can't open EFI_SHELL_PROTOCOL: %r\n", Status);
+ return EFI_SUCCESS;
+}
+```
+
+Then use `EFI_SHELL_PROTOCOL` functions in our while loop to create files with ACPI table data. For every table we will create a file "<signature>.aml". We use `.aml` extension for our files because in ACPI language source files usually have *.asl/*.dsl extension (ACPI Source Language), and compiled files have *.aml extension (ACPI Machine Language):
+```
+CHAR16 FileName[9] = {0};
+StrCpyS(FileName, 9, TableName);
+StrCatS(FileName, 9, L".aml");
+Print(L"%s\n", FileName);
+SHELL_FILE_HANDLE FileHandle;
+Status = ShellProtocol->OpenFileByName(FileName,
+ &FileHandle,
+ EFI_FILE_MODE_CREATE | EFI_FILE_MODE_WRITE | EFI_FILE_MODE_READ);
+
+if (!EFI_ERROR(Status)) {
+ UINTN size = table->Length;
+ Status = ShellProtocol->WriteFile(FileHandle, &size, (VOID*)table);
+ if (EFI_ERROR(Status)) {
+ Print(L"Error in WriteFile: %r\n", Status);
+ }
+ Status = ShellProtocol->CloseFile(FileHandle);
+ if (EFI_ERROR(Status)) {
+ Print(L"Error in CloseFile: %r\n", Status);
+ }
+} else {
+ Print(L"Error in OpenFileByName: %r\n", Status);
+}
+```
+
+To create a string with a file name we use `StrCatS` and `StrCpyS` functions. They are safe versions of string concatention/string copy functions similar to their C++ analogs `strcat_s`/`strcpy_s`. You can check out them in a library https://github.com/tianocore/edk2/blob/master/MdePkg/Library/BaseLib/SafeString.c
+
+With a help of `EFI_SHELL_PROTOCOL` file operation functions writing data to a file is pretty similar to standard system programming. We open handle, write data to it, and finally close handle.
+
+If you build our app and execute it under OVMF you would get 4 files in our `UEFI_disk` shared folder:
+```
+$ ls -1 ~/UEFI_disk/*.aml
+/home/kostr/UEFI_disk/apic.aml
+/home/kostr/UEFI_disk/bgrt.aml
+/home/kostr/UEFI_disk/facp.aml
+/home/kostr/UEFI_disk/hpet.aml
+```
+
+You can use `iasl` compiler to disassemle ACPI table data:
+```
+$ iasl -d ~/UEFI_disk/*.aml
+
+Intel ACPI Component Architecture
+ASL+ Optimizing Compiler/Disassembler version 20190509
+Copyright (c) 2000 - 2019 Intel Corporation
+
+File appears to be binary: found 81 non-ASCII characters, disassembling
+Binary file appears to be a valid ACPI table, disassembling
+Input file /home/kostr/UEFI_disk/apic.aml, Length 0x78 (120) bytes
+ACPI: APIC 0x0000000000000000 000078 (v01 BOCHS BXPCAPIC 00000001 BXPC 00000001)
+Acpi Data Table [APIC] decoded
+Formatted output: /home/kostr/UEFI_disk/apic.dsl - 4935 bytes
+File appears to be binary: found 32 non-ASCII characters, disassembling
+Binary file appears to be a valid ACPI table, disassembling
+Input file /home/kostr/UEFI_disk/bgrt.aml, Length 0x38 (56) bytes
+ACPI: BGRT 0x0000000000000000 000038 (v01 INTEL EDK2 00000002 01000013)
+Acpi Data Table [BGRT] decoded
+Formatted output: /home/kostr/UEFI_disk/bgrt.dsl - 1628 bytes
+File appears to be binary: found 91 non-ASCII characters, disassembling
+Binary file appears to be a valid ACPI table, disassembling
+Input file /home/kostr/UEFI_disk/facp.aml, Length 0x74 (116) bytes
+ACPI: FACP 0x0000000000000000 000074 (v01 BOCHS BXPCFACP 00000001 BXPC 00000001)
+Acpi Data Table [FACP] decoded
+Formatted output: /home/kostr/UEFI_disk/facp.dsl - 4892 bytes
+File appears to be binary: found 33 non-ASCII characters, disassembling
+Binary file appears to be a valid ACPI table, disassembling
+Input file /home/kostr/UEFI_disk/hpet.aml, Length 0x38 (56) bytes
+ACPI: HPET 0x0000000000000000 000038 (v01 BOCHS BXPCHPET 00000001 BXPC 00000001)
+Acpi Data Table [HPET] decoded
+Formatted output: /home/kostr/UEFI_disk/hpet.dsl - 1887 bytes
+```
+
+Now you have *.dsl files in the same `UEFI_disk` shared folder.
+
+For example here is a content for `APIC` table:
+```
+$ cat ~/UEFI_disk/apic.dsl
+/*
+ * Intel ACPI Component Architecture
+ * AML/ASL+ Disassembler version 20190509 (64-bit version)
+ * Copyright (c) 2000 - 2019 Intel Corporation
+ *
+ * Disassembly of /home/kostr/UEFI_disk/apic.aml, Sat Jul 3 00:09:16 2021
+ *
+ * ACPI Data Table [APIC]
+ *
+ * Format: [HexOffset DecimalOffset ByteLength] FieldName : FieldValue
+ */
+
+[000h 0000 4] Signature : "APIC" [Multiple APIC Description Table (MADT)]
+[004h 0004 4] Table Length : 00000078
+[008h 0008 1] Revision : 01
+[009h 0009 1] Checksum : ED
+[00Ah 0010 6] Oem ID : "BOCHS "
+[010h 0016 8] Oem Table ID : "BXPCAPIC"
+[018h 0024 4] Oem Revision : 00000001
+[01Ch 0028 4] Asl Compiler ID : "BXPC"
+[020h 0032 4] Asl Compiler Revision : 00000001
+
+[024h 0036 4] Local Apic Address : FEE00000
+[028h 0040 4] Flags (decoded below) : 00000001
+ PC-AT Compatibility : 1
+
+[02Ch 0044 1] Subtable Type : 00 [Processor Local APIC]
+[02Dh 0045 1] Length : 08
+[02Eh 0046 1] Processor ID : 00
+[02Fh 0047 1] Local Apic ID : 00
+[030h 0048 4] Flags (decoded below) : 00000001
+ Processor Enabled : 1
+ Runtime Online Capable : 0
+
+[034h 0052 1] Subtable Type : 01 [I/O APIC]
+[035h 0053 1] Length : 0C
+[036h 0054 1] I/O Apic ID : 00
+[037h 0055 1] Reserved : 00
+[038h 0056 4] Address : FEC00000
+[03Ch 0060 4] Interrupt : 00000000
+
+[040h 0064 1] Subtable Type : 02 [Interrupt Source Override]
+[041h 0065 1] Length : 0A
+[042h 0066 1] Bus : 00
+[043h 0067 1] Source : 00
+[044h 0068 4] Interrupt : 00000002
+[048h 0072 2] Flags (decoded below) : 0000
+ Polarity : 0
+ Trigger Mode : 0
+
+[04Ah 0074 1] Subtable Type : 02 [Interrupt Source Override]
+[04Bh 0075 1] Length : 0A
+[04Ch 0076 1] Bus : 00
+[04Dh 0077 1] Source : 05
+[04Eh 0078 4] Interrupt : 00000005
+[052h 0082 2] Flags (decoded below) : 000D
+ Polarity : 1
+ Trigger Mode : 3
+
+[054h 0084 1] Subtable Type : 02 [Interrupt Source Override]
+[055h 0085 1] Length : 0A
+[056h 0086 1] Bus : 00
+[057h 0087 1] Source : 09
+[058h 0088 4] Interrupt : 00000009
+[05Ch 0092 2] Flags (decoded below) : 000D
+ Polarity : 1
+ Trigger Mode : 3
+
+[05Eh 0094 1] Subtable Type : 02 [Interrupt Source Override]
+[05Fh 0095 1] Length : 0A
+[060h 0096 1] Bus : 00
+[061h 0097 1] Source : 0A
+[062h 0098 4] Interrupt : 0000000A
+[066h 0102 2] Flags (decoded below) : 000D
+ Polarity : 1
+ Trigger Mode : 3
+
+[068h 0104 1] Subtable Type : 02 [Interrupt Source Override]
+[069h 0105 1] Length : 0A
+[06Ah 0106 1] Bus : 00
+[06Bh 0107 1] Source : 0B
+[06Ch 0108 4] Interrupt : 0000000B
+[070h 0112 2] Flags (decoded below) : 000D
+ Polarity : 1
+ Trigger Mode : 3
+
+[072h 0114 1] Subtable Type : 04 [Local APIC NMI]
+[073h 0115 1] Length : 06
+[074h 0116 1] Processor ID : FF
+[075h 0117 2] Flags (decoded below) : 0000
+ Polarity : 0
+ Trigger Mode : 0
+[077h 0119 1] Interrupt Input LINT : 01
+
+Raw Table Data: Length 120 (0x78)
+
+ 0000: 41 50 49 43 78 00 00 00 01 ED 42 4F 43 48 53 20 // APICx.....BOCHS
+ 0010: 42 58 50 43 41 50 49 43 01 00 00 00 42 58 50 43 // BXPCAPIC....BXPC
+ 0020: 01 00 00 00 00 00 E0 FE 01 00 00 00 00 08 00 00 // ................
+ 0030: 01 00 00 00 01 0C 00 00 00 00 C0 FE 00 00 00 00 // ................
+ 0040: 02 0A 00 00 02 00 00 00 00 00 02 0A 00 05 05 00 // ................
+ 0050: 00 00 0D 00 02 0A 00 09 09 00 00 00 0D 00 02 0A // ................
+ 0060: 00 0A 0A 00 00 00 0D 00 02 0A 00 0B 0B 00 00 00 // ................
+ 0070: 0D 00 04 06 FF 00 00 01 // ........
+```
+
+
diff --git a/Lessons/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c b/Lessons/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c
new file mode 100644
index 0000000..0511f59
--- /dev/null
+++ b/Lessons/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c
@@ -0,0 +1,106 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Library/BaseMemoryLib.h>
+#include <Protocol/Shell.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_SHELL_PROTOCOL* ShellProtocol;
+ EFI_STATUS Status = gBS->LocateProtocol(
+ &gEfiShellProtocolGuid,
+ NULL,
+ (VOID **)&ShellProtocol
+ );
+
+ if (EFI_ERROR(Status)) {
+ Print(L"Can't open EFI_SHELL_PROTOCOL: %r\n", Status);
+ return EFI_SUCCESS;
+ }
+
+ EFI_ACPI_6_3_ROOT_SYSTEM_DESCRIPTION_POINTER* RSDP = NULL;
+
+ for (UINTN i=0; i<SystemTable->NumberOfTableEntries; i++) {
+ if (CompareGuid(&(SystemTable->ConfigurationTable[i].VendorGuid), &gEfiAcpi20TableGuid)) {
+ Print(L"RSDP table is placed at %p\n\n", SystemTable->ConfigurationTable[i].VendorTable);
+ RSDP = SystemTable->ConfigurationTable[i].VendorTable;
+ }
+ }
+
+ if (!RSDP) {
+ Print(L"No ACPI2.0 table was found in the system\n");
+ return EFI_SUCCESS;
+ }
+
+ if (((CHAR8)((RSDP->Signature >> 0) & 0xFF) != 'R') ||
+ ((CHAR8)((RSDP->Signature >> 8) & 0xFF) != 'S') ||
+ ((CHAR8)((RSDP->Signature >> 16) & 0xFF) != 'D') ||
+ ((CHAR8)((RSDP->Signature >> 24) & 0xFF) != ' ') ||
+ ((CHAR8)((RSDP->Signature >> 32) & 0xFF) != 'P') ||
+ ((CHAR8)((RSDP->Signature >> 40) & 0xFF) != 'T') ||
+ ((CHAR8)((RSDP->Signature >> 48) & 0xFF) != 'R') ||
+ ((CHAR8)((RSDP->Signature >> 56) & 0xFF) != ' ')) {
+ Print(L"Error! RSDP signature is not valid!\n");
+ return EFI_SUCCESS;
+ }
+
+ Print(L"System description tables:\n");
+ Print(L"\tRSDT table is placed at address %p\n", RSDP->RsdtAddress);
+ Print(L"\tXSDT table is placed at address %p\n", RSDP->XsdtAddress);
+ Print(L"\n");
+
+ EFI_ACPI_DESCRIPTION_HEADER* XSDT = (EFI_ACPI_DESCRIPTION_HEADER*)RSDP->XsdtAddress;
+ if (((CHAR8)((XSDT->Signature >> 0) & 0xFF) != 'X') ||
+ ((CHAR8)((XSDT->Signature >> 8) & 0xFF) != 'S') ||
+ ((CHAR8)((XSDT->Signature >> 16) & 0xFF) != 'D') ||
+ ((CHAR8)((XSDT->Signature >> 24) & 0xFF) != 'T')) {
+ Print(L"Error! XSDT signature is not valid!\n");
+ return EFI_SUCCESS;
+ }
+
+ Print(L"Main ACPI tables:\n");
+ UINT64 offset = sizeof(EFI_ACPI_DESCRIPTION_HEADER);
+ while (offset < XSDT->Length) {
+ UINT64* table_address = (UINT64*)((UINT8*)XSDT + offset);
+ EFI_ACPI_6_3_COMMON_HEADER* table = (EFI_ACPI_6_3_COMMON_HEADER*)(*table_address);
+ CHAR16 TableName[5];
+ TableName[0] = (CHAR16)((table->Signature>> 0)&0xFF);
+ TableName[1] = (CHAR16)((table->Signature>> 8)&0xFF);
+ TableName[2] = (CHAR16)((table->Signature>>16)&0xFF);
+ TableName[3] = (CHAR16)((table->Signature>>24)&0xFF);
+ TableName[4] = 0;
+
+ Print(L"\t%s table is placed at address %p with length 0x%x\n",
+ TableName,
+ table,
+ table->Length);
+ CHAR16 FileName[9] = {0};
+ StrCpyS(FileName, 9, TableName);
+ StrCatS(FileName, 9, L".aml");
+ SHELL_FILE_HANDLE FileHandle;
+ Status = ShellProtocol->OpenFileByName(FileName,
+ &FileHandle,
+ EFI_FILE_MODE_CREATE | EFI_FILE_MODE_WRITE | EFI_FILE_MODE_READ);
+ if (!EFI_ERROR(Status)) {
+ UINTN size = table->Length;
+ Status = ShellProtocol->WriteFile(FileHandle, &size, (VOID*)table);
+ if (EFI_ERROR(Status)) {
+ Print(L"Error in WriteFile: %r\n", Status);
+ }
+ Status = ShellProtocol->CloseFile(FileHandle);
+ if (EFI_ERROR(Status)) {
+ Print(L"Error in CloseFile: %r\n", Status);
+ }
+ } else {
+ Print(L"Error in OpenFileByName: %r\n", Status);
+ }
+ offset += sizeof(UINT64);
+ }
+
+ return EFI_SUCCESS;
+}
diff --git a/Lessons/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.inf b/Lessons/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.inf
new file mode 100644
index 0000000..53d0356
--- /dev/null
+++ b/Lessons/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.inf
@@ -0,0 +1,24 @@
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = AcpiInfo
+ FILE_GUID = 18998798-69a2-4ab5-9ffc-a8ee2494b029
+ MODULE_TYPE = UEFI_APPLICATION
+ VERSION_STRING = 1.0
+ ENTRY_POINT = UefiMain
+
+[Sources]
+ AcpiInfo.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ UefiApplicationEntryPoint
+ UefiLib
+
+[Guids]
+ gEfiAcpi20TableGuid
+
+[Protocols]
+ gEfiShellProtocolGuid
+