diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
index fa6d0d5df2..8ddb52a5ac 100644
--- a/MdePkg/Include/Base.h
+++ b/MdePkg/Include/Base.h
@@ -1,5 +1,4 @@
/** @file
-
Root include file for Mde Package Base type modules
This is the include file for any module of type base. Base modules only use
@@ -282,5 +281,13 @@ typedef INTN RETURN_STATUS;
#define RETURN_WARN_WRITE_FAILURE ENCODE_WARNING (3)
#define RETURN_WARN_BUFFER_TOO_SMALL ENCODE_WARNING (4)
+//
+// Define macros to build data structure signatures from characters.
+//
+#define SIGNATURE_16(A, B) ((A) | (B << 8))
+#define SIGNATURE_32(A, B, C, D) (SIGNATURE_16 (A, B) | (SIGNATURE_16 (C, D) << 16))
+#define SIGNATURE_64(A, B, C, D, E, F, G, H) \
+ (SIGNATURE_32 (A, B, C, D) | ((UINT64) (SIGNATURE_32 (E, F, G, H)) << 32))
+
#endif
diff --git a/MdePkg/Include/IndustryStandard/Acpi10.h b/MdePkg/Include/IndustryStandard/Acpi10.h
index 4d970fff36..bd05553e04 100644
--- a/MdePkg/Include/IndustryStandard/Acpi10.h
+++ b/MdePkg/Include/IndustryStandard/Acpi10.h
@@ -352,47 +352,47 @@ typedef struct {
///
/// "RSD PTR " Root System Description Pointer
///
-#define EFI_ACPI_1_0_ROOT_SYSTEM_DESCRIPTION_POINTER_SIGNATURE 0x2052545020445352ULL
+#define EFI_ACPI_1_0_ROOT_SYSTEM_DESCRIPTION_POINTER_SIGNATURE SIGNATURE_64('R', 'S', 'D', ' ', 'P', 'T', 'R', ' ')
///
/// "APIC" Multiple APIC Description Table
///
-#define EFI_ACPI_1_0_APIC_SIGNATURE 0x43495041
+#define EFI_ACPI_1_0_APIC_SIGNATURE SIGNATURE_32('A', 'P', 'I', 'C')
///
/// "DSDT" Differentiated System Description Table
///
-#define EFI_ACPI_1_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445344
+#define EFI_ACPI_1_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('D', 'S', 'D', 'T')
///
/// "FACS" Firmware ACPI Control Structure
///
-#define EFI_ACPI_1_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE 0x53434146
+#define EFI_ACPI_1_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE SIGNATURE_32('F', 'A', 'C', 'S')
///
/// "FACP" Fixed ACPI Description Table
///
-#define EFI_ACPI_1_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE 0x50434146
+#define EFI_ACPI_1_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('F', 'A', 'C', 'P')
///
/// "PSDT" Persistent System Description Table
///
-#define EFI_ACPI_1_0_PERSISTENT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445350
+#define EFI_ACPI_1_0_PERSISTENT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('P', 'S', 'D', 'T')
///
/// "RSDT" Root System Description Table
///
-#define EFI_ACPI_1_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445352
+#define EFI_ACPI_1_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('R', 'S', 'D', 'T')
///
/// "SBST" Smart Battery Specification Table
///
-#define EFI_ACPI_1_0_SMART_BATTERY_SPECIFICATION_TABLE_SIGNATURE 0x54534253
+#define EFI_ACPI_1_0_SMART_BATTERY_SPECIFICATION_TABLE_SIGNATURE SIGNATURE_32('S', 'B', 'S', 'T')
///
/// "SSDT" Secondary System Description Table
///
-#define EFI_ACPI_1_0_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445353
+#define EFI_ACPI_1_0_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('S', 'S', 'D', 'T')
#pragma pack()
diff --git a/MdePkg/Include/IndustryStandard/Acpi20.h b/MdePkg/Include/IndustryStandard/Acpi20.h
index 3b5a4e8a89..9c1db57a42 100644
--- a/MdePkg/Include/IndustryStandard/Acpi20.h
+++ b/MdePkg/Include/IndustryStandard/Acpi20.h
@@ -403,7 +403,7 @@ typedef struct {
///
/// "RSD PTR " Root System Description Pointer
///
-#define EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_SIGNATURE 0x2052545020445352
+#define EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_SIGNATURE SIGNATURE_64('R', 'S', 'D', ' ', 'P', 'T', 'R', ' ')
///
/// "SPIC" Multiple SAPIC Description Table
@@ -411,97 +411,97 @@ typedef struct {
/// BUGBUG: Don't know where this came from except SR870BN4 uses it.
/// #define EFI_ACPI_2_0_MULTIPLE_SAPIC_DESCRIPTION_TABLE_SIGNATURE 0x43495053
///
-#define EFI_ACPI_2_0_MULTIPLE_SAPIC_DESCRIPTION_TABLE_SIGNATURE 0x43495041
+#define EFI_ACPI_2_0_MULTIPLE_SAPIC_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('S', 'P', 'I', 'C')
///
/// "BOOT" MS Simple Boot Spec
///
-#define EFI_ACPI_2_0_SIMPLE_BOOT_FLAG_TABLE_SIGNATURE 0x544F4F42
+#define EFI_ACPI_2_0_SIMPLE_BOOT_FLAG_TABLE_SIGNATURE SIGNATURE_32('B', 'O', 'O', 'T')
///
/// "DBGP" MS Bebug Port Spec
///
-#define EFI_ACPI_2_0_DEBUG_PORT_TABLE_SIGNATURE 0x50474244
+#define EFI_ACPI_2_0_DEBUG_PORT_TABLE_SIGNATURE SIGNATURE_32('D', 'B', 'G', 'P')
///
/// "DSDT" Differentiated System Description Table
///
-#define EFI_ACPI_2_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445344
+#define EFI_ACPI_2_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('D', 'S', 'D', 'T')
///
/// "ECDT" Embedded Controller Boot Resources Table
///
-#define EFI_ACPI_2_0_EMBEDDED_CONTROLLER_BOOT_RESOURCES_TABLE_SIGNATURE 0x54444345
+#define EFI_ACPI_2_0_EMBEDDED_CONTROLLER_BOOT_RESOURCES_TABLE_SIGNATURE SIGNATURE_32('E', 'C', 'D', 'T')
///
/// "ETDT" Event Timer Description Table
///
-#define EFI_ACPI_2_0_EVENT_TIMER_DESCRIPTION_TABLE_SIGNATURE 0x54445445
+#define EFI_ACPI_2_0_EVENT_TIMER_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('E', 'T', 'D', 'T')
///
/// "FACS" Firmware ACPI Control Structure
///
-#define EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE 0x53434146
+#define EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE SIGNATURE_32('F', 'A', 'C', 'S')
///
/// "FACP" Fixed ACPI Description Table
///
-#define EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE 0x50434146
+#define EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('F', 'A', 'C', 'P')
///
/// "APIC" Multiple APIC Description Table
///
-#define EFI_ACPI_2_0_MULTIPLE_APIC_DESCRIPTION_TABLE_SIGNATURE 0x43495041
+#define EFI_ACPI_2_0_MULTIPLE_APIC_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('A', 'P', 'I', 'C')
///
/// "PSDT" Persistent System Description Table
///
-#define EFI_ACPI_2_0_PERSISTENT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445350
+#define EFI_ACPI_2_0_PERSISTENT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('P', 'S', 'D', 'T')
///
/// "RSDT" Root System Description Table
///
-#define EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445352
+#define EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('R', 'S', 'D', 'T')
///
/// "SBST" Smart Battery Specification Table
///
-#define EFI_ACPI_2_0_SMART_BATTERY_SPECIFICATION_TABLE_SIGNATURE 0x54534253
+#define EFI_ACPI_2_0_SMART_BATTERY_SPECIFICATION_TABLE_SIGNATURE SIGNATURE_32('S', 'B', 'S', 'T')
///
/// "SLIT" System Locality Information Table
///
-#define EFI_ACPI_2_0_SYSTEM_LOCALITY_INFORMATION_TABLE_SIGNATURE 0x54494C53
+#define EFI_ACPI_2_0_SYSTEM_LOCALITY_INFORMATION_TABLE_SIGNATURE SIGNATURE_32('S', 'L', 'I', 'T')
///
/// "SPCR" Serial Port Concole Redirection Table
///
-#define EFI_ACPI_2_0_SERIAL_PORT_CONSOLE_REDIRECTION_TABLE_SIGNATURE 0x52435053
+#define EFI_ACPI_2_0_SERIAL_PORT_CONSOLE_REDIRECTION_TABLE_SIGNATURE SIGNATURE_32('S', 'P', 'C', 'R')
///
/// "SRAT" Static Resource Affinity Table
///
-#define EFI_ACPI_2_0_STATIC_RESOURCE_AFFINITY_TABLE_SIGNATURE 0x54415253
+#define EFI_ACPI_2_0_STATIC_RESOURCE_AFFINITY_TABLE_SIGNATURE SIGNATURE_32('S', 'R', 'A', 'T')
///
/// "SSDT" Secondary System Description Table
///
-#define EFI_ACPI_2_0_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445353
+#define EFI_ACPI_2_0_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('S', 'S', 'D', 'T')
///
/// "SPMI" Server Platform Management Interface Table
///
-#define EFI_ACPI_2_0_SERVER_PLATFORM_MANAGEMENT_INTERFACE_SIGNATURE 0x494D5053
+#define EFI_ACPI_2_0_SERVER_PLATFORM_MANAGEMENT_INTERFACE_SIGNATURE SIGNATURE_32('S', 'P', 'M', 'I')
///
/// "XSDT" Extended System Description Table
///
-#define EFI_ACPI_2_0_EXTENDED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445358
+#define EFI_ACPI_2_0_EXTENDED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('X', 'S', 'D', 'T')
///
/// "MCFG" Static Resource Affinity Table
///
-#define EFI_ACPI_2_0_MEMORY_MAPPED_CONFIGURATION_BASE_ADDRESS_TABLE_SIGNATURE 0x4746434D
+#define EFI_ACPI_2_0_MEMORY_MAPPED_CONFIGURATION_BASE_ADDRESS_TABLE_SIGNATURE SIGNATURE_32('M', 'C', 'F', 'G')
#pragma pack()
diff --git a/MdePkg/Include/IndustryStandard/Acpi30.h b/MdePkg/Include/IndustryStandard/Acpi30.h
index 5414ef5c16..75b5f8eba8 100644
--- a/MdePkg/Include/IndustryStandard/Acpi30.h
+++ b/MdePkg/Include/IndustryStandard/Acpi30.h
@@ -555,128 +555,128 @@ typedef struct {
///
/// "RSD PTR " Root System Description Pointer
///
-#define EFI_ACPI_3_0_ROOT_SYSTEM_DESCRIPTION_POINTER_SIGNATURE 0x2052545020445352ULL
+#define EFI_ACPI_3_0_ROOT_SYSTEM_DESCRIPTION_POINTER_SIGNATURE SIGNATURE_64('R', 'S', 'D', ' ', 'P', 'T', 'R', ' ')
///
/// "APIC" Multiple APIC Description Table
///
-#define EFI_ACPI_3_0_MULTIPLE_APIC_DESCRIPTION_TABLE_SIGNATURE 0x43495041
+#define EFI_ACPI_3_0_MULTIPLE_APIC_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('A', 'P', 'I', 'C')
///
/// "DSDT" Differentiated System Description Table
///
-#define EFI_ACPI_3_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445344
+#define EFI_ACPI_3_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('D', 'S', 'D', 'T')
///
/// "ECDT" Embedded Controller Boot Resources Table
///
-#define EFI_ACPI_3_0_EMBEDDED_CONTROLLER_BOOT_RESOURCES_TABLE_SIGNATURE 0x54444345
+#define EFI_ACPI_3_0_EMBEDDED_CONTROLLER_BOOT_RESOURCES_TABLE_SIGNATURE SIGNATURE_32('E', 'C', 'D', 'T')
///
/// "FACP" Fixed ACPI Description Table
///
-#define EFI_ACPI_3_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE 0x50434146
+#define EFI_ACPI_3_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('F', 'A', 'C', 'P')
///
/// "FACS" Firmware ACPI Control Structure
///
-#define EFI_ACPI_3_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE 0x53434146
+#define EFI_ACPI_3_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE SIGNATURE_32('F', 'A', 'C', 'S')
///
/// "PSDT" Persistent System Description Table
///
-#define EFI_ACPI_3_0_PERSISTENT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445350
+#define EFI_ACPI_3_0_PERSISTENT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('P', 'S', 'D', 'T')
///
/// "RSDT" Root System Description Table
///
-#define EFI_ACPI_3_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445352
+#define EFI_ACPI_3_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('R', 'S', 'D', 'T')
///
/// "SBST" Smart Battery Specification Table
///
-#define EFI_ACPI_3_0_SMART_BATTERY_SPECIFICATION_TABLE_SIGNATURE 0x54534253
+#define EFI_ACPI_3_0_SMART_BATTERY_SPECIFICATION_TABLE_SIGNATURE SIGNATURE_32('S', 'B', 'S', 'T')
///
/// "SLIT" System Locality Information Table
///
-#define EFI_ACPI_3_0_SYSTEM_LOCALITY_INFORMATION_TABLE_SIGNATURE 0x54494C53
+#define EFI_ACPI_3_0_SYSTEM_LOCALITY_INFORMATION_TABLE_SIGNATURE SIGNATURE_32('S', 'L', 'I', 'T')
///
/// "SRAT" System Resource Affinity Table
///
-#define EFI_ACPI_3_0_SYSTEM_RESOURCE_AFFINITY_TABLE_SIGNATURE 0x54415253
+#define EFI_ACPI_3_0_SYSTEM_RESOURCE_AFFINITY_TABLE_SIGNATURE SIGNATURE_32('S', 'R', 'A', 'T')
///
/// "SSDT" Secondary System Description Table
///
-#define EFI_ACPI_3_0_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445353
+#define EFI_ACPI_3_0_SECONDARY_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('S', 'S', 'D', 'T')
///
/// "XSDT" Extended System Description Table
///
-#define EFI_ACPI_3_0_EXTENDED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE 0x54445358
+#define EFI_ACPI_3_0_EXTENDED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('X', 'S', 'D', 'T')
///
/// "BOOT" MS Simple Boot Spec
///
-#define EFI_ACPI_3_0_SIMPLE_BOOT_FLAG_TABLE_SIGNATURE 0x544F4F42
+#define EFI_ACPI_3_0_SIMPLE_BOOT_FLAG_TABLE_SIGNATURE SIGNATURE_32('B', 'O', 'O', 'T')
///
/// "CPEP" Corrected Platform Error Polling Table
/// See
///
-#define EFI_ACPI_3_0_CORRECTED_PLATFORM_ERROR_POLLING_TABLE_SIGNATURE 0x50455043
+#define EFI_ACPI_3_0_CORRECTED_PLATFORM_ERROR_POLLING_TABLE_SIGNATURE SIGNATURE_32('C', 'P', 'E', 'P')
///
/// "DBGP" MS Debug Port Spec
///
-#define EFI_ACPI_3_0_DEBUG_PORT_TABLE_SIGNATURE 0x50474244
+#define EFI_ACPI_3_0_DEBUG_PORT_TABLE_SIGNATURE SIGNATURE_32('D', 'B', 'G', 'P')
///
/// "ETDT" Event Timer Description Table
///
-#define EFI_ACPI_3_0_EVENT_TIMER_DESCRIPTION_TABLE_SIGNATURE 0x54445445
+#define EFI_ACPI_3_0_EVENT_TIMER_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('E', 'T', 'D', 'T')
///
/// "HPET" IA-PC High Precision Event Timer Table
///
-#define EFI_ACPI_3_0_HIGH_PRECISION_EVENT_TIMER_TABLE_SIGNATURE 0x54455048
+#define EFI_ACPI_3_0_HIGH_PRECISION_EVENT_TIMER_TABLE_SIGNATURE SIGNATURE_32('H', 'P', 'E', 'T')
///
/// "MCFG" PCI Express Memory Mapped Configuration Space Base Address Description Table
///
-#define EFI_ACPI_3_0_PCI_EXPRESS_MEMORY_MAPPED_CONFIGURATION_SPACE_BASE_ADDRESS_DESCRIPTION_TABLE_SIGNATURE 0x4746434D
+#define EFI_ACPI_3_0_PCI_EXPRESS_MEMORY_MAPPED_CONFIGURATION_SPACE_BASE_ADDRESS_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32('M', 'C', 'F', 'G')
///
/// "SPCR" Serial Port Concole Redirection Table
///
-#define EFI_ACPI_3_0_SERIAL_PORT_CONSOLE_REDIRECTION_TABLE_SIGNATURE 0x52435053
+#define EFI_ACPI_3_0_SERIAL_PORT_CONSOLE_REDIRECTION_TABLE_SIGNATURE SIGNATURE_32('S', 'P', 'C', 'R')
///
/// "SPMI" Server Platform Management Interface Table
///
-#define EFI_ACPI_3_0_SERVER_PLATFORM_MANAGEMENT_INTERFACE_TABLE_SIGNATURE 0x494D5053
+#define EFI_ACPI_3_0_SERVER_PLATFORM_MANAGEMENT_INTERFACE_TABLE_SIGNATURE SIGNATURE_32('S', 'P', 'M', 'I')
///
/// "TCPA" Trusted Computing Platform Alliance Capabilities Table
///
-#define EFI_ACPI_3_0_TRUSTED_COMPUTING_PLATFORM_ALLIANCE_CAPABILITIES_TABLE_SIGNATURE 0x41504354
+#define EFI_ACPI_3_0_TRUSTED_COMPUTING_PLATFORM_ALLIANCE_CAPABILITIES_TABLE_SIGNATURE SIGNATURE_32('T', 'C', 'P', 'A')
///
/// "WDRT" Watchdog Resource Table
///
-#define EFI_ACPI_3_0_WATCHDOG_RESOURCE_TABLE_SIGNATURE 0x54524457
+#define EFI_ACPI_3_0_WATCHDOG_RESOURCE_TABLE_SIGNATURE SIGNATURE_32('W', 'D', 'R', 'T')
///
/// "WDAT" Watchdog Action Table
///
-#define EFI_ACPI_3_0_WATCHDOG_ACTION_TABLE_SIGNATURE 0x54414457
+#define EFI_ACPI_3_0_WATCHDOG_ACTION_TABLE_SIGNATURE SIGNATURE_32('W', 'D', 'A', 'T')
///
/// "iBFT" iSCSI Boot Firmware Table
///
-#define EFI_ACPI_3_0_ISCSI_BOOT_FIRMWARE_TABLE_SIGNATURE 0x54464269
+#define EFI_ACPI_3_0_ISCSI_BOOT_FIRMWARE_TABLE_SIGNATURE SIGNATURE_32('i', 'B', 'F', 'T')
#pragma pack()
diff --git a/MdePkg/Include/IndustryStandard/AlertStandardFormatTable.h b/MdePkg/Include/IndustryStandard/AlertStandardFormatTable.h
index 0d7f539c9c..ef2462e654 100644
--- a/MdePkg/Include/IndustryStandard/AlertStandardFormatTable.h
+++ b/MdePkg/Include/IndustryStandard/AlertStandardFormatTable.h
@@ -139,7 +139,7 @@ typedef EFI_ACPI_DESCRIPTION_HEADER EFI_ACPI_ASF_DESCRIPTION_HEADER;
///
/// "ASF!" ASF Description Table Signature
///
-#define EFI_ACPI_ASF_DESCRIPTION_TABLE_SIGNATURE EFI_SIGNATURE_32 ('A', 'S', 'F', '!')
+#define EFI_ACPI_ASF_DESCRIPTION_TABLE_SIGNATURE SIGNATURE_32 ('A', 'S', 'F', '!')
#pragma pack ()
diff --git a/MdePkg/Include/IndustryStandard/ElTorito.h b/MdePkg/Include/IndustryStandard/ElTorito.h
index b474dc9ba1..12375015ef 100644
--- a/MdePkg/Include/IndustryStandard/ElTorito.h
+++ b/MdePkg/Include/IndustryStandard/ElTorito.h
@@ -58,12 +58,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#pragma pack(1)
///
-/// El Torito Volume Descriptor
-/// Note that the CDROM_VOLUME_DESCRIPTOR does not match the ISO-9660
-/// descriptor. For some reason descriptor used by El Torito is
-/// different, but they start the same. The El Torito descriptor
-/// is left shifted 1 byte starting with the SystemId. (Note this
-/// causes the field to get unaligned)
+/// CD-ROM Volume Descriptor
///
typedef union {
struct {
diff --git a/MdePkg/Include/IndustryStandard/Pci22.h b/MdePkg/Include/IndustryStandard/Pci22.h
index 4a613f4e38..d88b28f825 100644
--- a/MdePkg/Include/IndustryStandard/Pci22.h
+++ b/MdePkg/Include/IndustryStandard/Pci22.h
@@ -541,7 +541,7 @@ typedef struct {
} DEFIO_PCI_ADDR;
#define PCI_EXPANSION_ROM_HEADER_SIGNATURE 0xaa55
-#define PCI_DATA_STRUCTURE_SIGNATURE EFI_SIGNATURE_32 ('P', 'C', 'I', 'R')
+#define PCI_DATA_STRUCTURE_SIGNATURE SIGNATURE_32 ('P', 'C', 'I', 'R')
#define PCI_CODE_TYPE_PCAT_IMAGE 0x00
#define EFI_PCI_EXPANSION_ROM_HEADER_COMPRESSED 0x0001 ///<defined in UEFI spec.
diff --git a/MdePkg/Include/IndustryStandard/PeImage.h b/MdePkg/Include/IndustryStandard/PeImage.h
index 90691f31af..ec4819e472 100644
--- a/MdePkg/Include/IndustryStandard/PeImage.h
+++ b/MdePkg/Include/IndustryStandard/PeImage.h
@@ -51,10 +51,10 @@
///
/// EXE file formats
///
-#define EFI_IMAGE_DOS_SIGNATURE 0x5A4D ///< MZ
-#define EFI_IMAGE_OS2_SIGNATURE 0x454E ///< NE
-#define EFI_IMAGE_OS2_SIGNATURE_LE 0x454C ///< LE
-#define EFI_IMAGE_NT_SIGNATURE 0x00004550 ///< PE00
+#define EFI_IMAGE_DOS_SIGNATURE SIGNATURE_16('M', 'Z')
+#define EFI_IMAGE_OS2_SIGNATURE SIGNATURE_16('N', 'E')
+#define EFI_IMAGE_OS2_SIGNATURE_LE SIGNATURE_16('L', 'E')
+#define EFI_IMAGE_NT_SIGNATURE SIGNATURE_32('P', 'E', '0', '0')
///
/// PE images can start with an optional DOS header, so if an image is run
@@ -681,7 +681,7 @@ typedef struct {
///
/// Debug Data Structure defined in Microsoft C++
///
-#define CODEVIEW_SIGNATURE_NB10 0x3031424E // "NB10"
+#define CODEVIEW_SIGNATURE_NB10 SIGNATURE_32('N', 'B', '1', '0')
typedef struct {
UINT32 Signature; ///< "NB10"
UINT32 Unknown;
@@ -695,7 +695,7 @@ typedef struct {
///
/// Debug Data Structure defined in Microsoft C++
///
-#define CODEVIEW_SIGNATURE_RSDS 0x53445352 // "RSDS"
+#define CODEVIEW_SIGNATURE_RSDS SIGNATURE_32('R', 'S', 'D', 'S')
typedef struct {
UINT32 Signature; ///< "RSDS"
UINT32 Unknown;
@@ -724,7 +724,7 @@ typedef struct {
} EFI_TE_IMAGE_HEADER;
-#define EFI_TE_IMAGE_HEADER_SIGNATURE 0x5A56 ///< "VZ"
+#define EFI_TE_IMAGE_HEADER_SIGNATURE SIGNATURE_16('V', 'Z')
//
// Data directory indexes in our TE image header
diff --git a/MdePkg/Include/Uefi/UefiBaseType.h b/MdePkg/Include/Uefi/UefiBaseType.h
index fff78a80e5..fb87559c45 100644
--- a/MdePkg/Include/Uefi/UefiBaseType.h
+++ b/MdePkg/Include/Uefi/UefiBaseType.h
@@ -157,11 +157,10 @@ typedef union {
//
// Define macros to build data structure signatures from characters.
//
-#define EFI_SIGNATURE_16(A, B) ((A) | (B << 8))
-#define EFI_SIGNATURE_32(A, B, C, D) (EFI_SIGNATURE_16 (A, B) | (EFI_SIGNATURE_16 (C, D) << 16))
-#define EFI_SIGNATURE_64(A, B, C, D, E, F, G, H) \
- (EFI_SIGNATURE_32 (A, B, C, D) | ((UINT64) (EFI_SIGNATURE_32 (E, F, G, H)) << 32))
-
+#define EFI_SIGNATURE_16(A, B) SIGNATURE_16 (A, B)
+#define EFI_SIGNATURE_32(A, B, C, D) SIGNATURE_32 (A, B, C, D)
+#define EFI_SIGNATURE_64(A, B, C, D, E, F, G, H) SIGNATURE_64 (A, B, C, D, E, F, G, H)
+
///
/// Returns the byte offset to a field within a structure