diff --git a/ArmPkg/Drivers/ArmGic/ArmGicCommonDxe.c b/ArmPkg/Drivers/ArmGic/ArmGicCommonDxe.c
index cd12fcda27..d560c42fc9 100644
--- a/ArmPkg/Drivers/ArmGic/ArmGicCommonDxe.c
+++ b/ArmPkg/Drivers/ArmGic/ArmGicCommonDxe.c
@@ -137,7 +137,7 @@ CpuArchEventProtocolNotify (
     DEBUG ((
       DEBUG_ERROR,
       "%a: Cpu->RegisterInterruptHandler() - %r\n",
-      __FUNCTION__,
+      __func__,
       Status
       ));
     return;
@@ -153,7 +153,7 @@ CpuArchEventProtocolNotify (
     DEBUG ((
       DEBUG_ERROR,
       "%a: Cpu->RegisterInterruptHandler() - %r\n",
-      __FUNCTION__,
+      __func__,
       Status
       ));
   }
diff --git a/ArmPkg/Drivers/CpuDxe/MemoryAttribute.c b/ArmPkg/Drivers/CpuDxe/MemoryAttribute.c
index cbc8261a68..61ba8fbbae 100644
--- a/ArmPkg/Drivers/CpuDxe/MemoryAttribute.c
+++ b/ArmPkg/Drivers/CpuDxe/MemoryAttribute.c
@@ -92,7 +92,7 @@ GetMemoryAttributes (
   DEBUG ((
     DEBUG_VERBOSE,
     "%a: BaseAddress == 0x%lx, Length == 0x%lx\n",
-    __FUNCTION__,
+    __func__,
     BaseAddress,
     Length
     ));
@@ -113,7 +113,7 @@ GetMemoryAttributes (
     DEBUG ((
       DEBUG_VERBOSE,
       "%a: RegionAddress == 0x%lx, RegionLength == 0x%lx, RegionAttributes == 0x%lx\n",
-      __FUNCTION__,
+      __func__,
       (UINT64)RegionAddress,
       (UINT64)RegionLength,
       (UINT64)RegionAttributes
@@ -130,7 +130,7 @@ GetMemoryAttributes (
   DEBUG ((
     DEBUG_VERBOSE,
     "%a: Union == %lx, Intersection == %lx\n",
-    __FUNCTION__,
+    __func__,
     (UINT64)Union,
     (UINT64)Intersection
     ));
@@ -188,7 +188,7 @@ SetMemoryAttributes (
   DEBUG ((
     DEBUG_INFO,
     "%a: BaseAddress == 0x%lx, Length == 0x%lx, Attributes == 0x%lx\n",
-    __FUNCTION__,
+    __func__,
     (UINTN)BaseAddress,
     (UINTN)Length,
     (UINTN)Attributes
@@ -272,7 +272,7 @@ ClearMemoryAttributes (
   DEBUG ((
     DEBUG_INFO,
     "%a: BaseAddress == 0x%lx, Length == 0x%lx, Attributes == 0x%lx\n",
-    __FUNCTION__,
+    __func__,
     (UINTN)BaseAddress,
     (UINTN)Length,
     (UINTN)Attributes
diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
index 7acfd2e89a..7ed758fbbc 100644
--- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
+++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
@@ -139,7 +139,7 @@ ReplaceTableEntry (
         (((RegionStart ^ (UINTN)Entry) & ~BlockMask) == 0))
     {
       DisableMmu = TRUE;
-      DEBUG ((DEBUG_WARN, "%a: splitting block entry with MMU disabled\n", __FUNCTION__));
+      DEBUG ((DEBUG_WARN, "%a: splitting block entry with MMU disabled\n", __func__));
     }
 
     mReplaceLiveEntryFunc (Entry, Value, RegionStart, DisableMmu);
@@ -233,7 +233,7 @@ UpdateRegionMappingRecursive (
   DEBUG ((
     DEBUG_VERBOSE,
     "%a(%d): %llx - %llx set %lx clr %lx\n",
-    __FUNCTION__,
+    __func__,
     Level,
     RegionStart,
     RegionEnd,
diff --git a/ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.c b/ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.c
index 7bcd348495..02b0c27e4d 100644
--- a/ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.c
+++ b/ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.c
@@ -65,7 +65,7 @@ LibResetSystem (
   ArmCallSmc (&ArmSmcArgs);
 
   // We should never be here
-  DEBUG ((DEBUG_ERROR, "%a: PSCI Reset failed\n", __FUNCTION__));
+  DEBUG ((DEBUG_ERROR, "%a: PSCI Reset failed\n", __func__));
   CpuDeadLoop ();
   return EFI_UNSUPPORTED;
 }
diff --git a/ArmPkg/Library/LinuxBootBootManagerLib/LinuxBootBm.c b/ArmPkg/Library/LinuxBootBootManagerLib/LinuxBootBm.c
index 5a44af5a75..75998eabb1 100644
--- a/ArmPkg/Library/LinuxBootBootManagerLib/LinuxBootBm.c
+++ b/ArmPkg/Library/LinuxBootBootManagerLib/LinuxBootBm.c
@@ -151,7 +151,7 @@ PlatformBootManagerAfterConsole (
       LOAD_OPTION_ACTIVE
       );
   } else {
-    DEBUG ((DEBUG_ERROR, "%a: PcdLinuxBootFileGuid was not set!\n", __FUNCTION__));
+    DEBUG ((DEBUG_ERROR, "%a: PcdLinuxBootFileGuid was not set!\n", __func__));
   }
 }
 
diff --git a/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c b/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c
index 2fb1a4aa4f..08998ffe4d 100644
--- a/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c
+++ b/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c
@@ -195,7 +195,7 @@ FilterAndProcess (
     DEBUG ((
       DEBUG_VERBOSE,
       "%a: %g: %r\n",
-      __FUNCTION__,
+      __func__,
       ProtocolGuid,
       Status
       ));
@@ -266,7 +266,7 @@ IsPciDisplay (
                         &Pci
                         );
   if (EFI_ERROR (Status)) {
-    DEBUG ((DEBUG_ERROR, "%a: %s: %r\n", __FUNCTION__, ReportText, Status));
+    DEBUG ((DEBUG_ERROR, "%a: %s: %r\n", __func__, ReportText, Status));
     return FALSE;
   }
 
@@ -330,7 +330,7 @@ Connect (
   DEBUG ((
     EFI_ERROR (Status) ? DEBUG_ERROR : DEBUG_VERBOSE,
     "%a: %s: %r\n",
-    __FUNCTION__,
+    __func__,
     ReportText,
     Status
     ));
@@ -356,7 +356,7 @@ AddOutput (
     DEBUG ((
       DEBUG_ERROR,
       "%a: %s: handle %p: device path not found\n",
-      __FUNCTION__,
+      __func__,
       ReportText,
       Handle
       ));
@@ -368,7 +368,7 @@ AddOutput (
     DEBUG ((
       DEBUG_ERROR,
       "%a: %s: adding to ConOut: %r\n",
-      __FUNCTION__,
+      __func__,
       ReportText,
       Status
       ));
@@ -380,7 +380,7 @@ AddOutput (
     DEBUG ((
       DEBUG_ERROR,
       "%a: %s: adding to ErrOut: %r\n",
-      __FUNCTION__,
+      __func__,
       ReportText,
       Status
       ));
@@ -390,7 +390,7 @@ AddOutput (
   DEBUG ((
     DEBUG_VERBOSE,
     "%a: %s: added to ConOut and ErrOut\n",
-    __FUNCTION__,
+    __func__,
     ReportText
     ));
 }
@@ -547,7 +547,7 @@ GetPlatformOptions (
         DEBUG ((
           DEBUG_ERROR,
           "%a: failed to register \"%s\": %r\n",
-          __FUNCTION__,
+          __func__,
           BootOptions[Index].Description,
           Status
           ));
@@ -575,7 +575,7 @@ GetPlatformOptions (
       DEBUG ((
         DEBUG_ERROR,
         "%a: failed to register hotkey for \"%s\": %r\n",
-        __FUNCTION__,
+        __func__,
         BootOptions[Index].Description,
         Status
         ));
@@ -757,7 +757,7 @@ HandleCapsules (
   BOOLEAN                   NeedReset;
   EFI_STATUS                Status;
 
-  DEBUG ((DEBUG_INFO, "%a: processing capsules ...\n", __FUNCTION__));
+  DEBUG ((DEBUG_INFO, "%a: processing capsules ...\n", __func__));
 
   Status = gBS->LocateProtocol (
                   &gEsrtManagementProtocolGuid,
@@ -785,7 +785,7 @@ HandleCapsules (
       DEBUG ((
         DEBUG_ERROR,
         "%a: failed to process capsule %p - %r\n",
-        __FUNCTION__,
+        __func__,
         CapsuleHeader,
         Status
         ));
@@ -800,7 +800,7 @@ HandleCapsules (
     DEBUG ((
       DEBUG_WARN,
       "%a: capsule update successful, resetting ...\n",
-      __FUNCTION__
+      __func__
       ));
 
     gRT->ResetSystem (EfiResetCold, EFI_SUCCESS, 0, NULL);
@@ -868,7 +868,7 @@ BootDiscoveryPolicyHandler (
       DEBUG ((
         DEBUG_INFO,
         "%a - Unexpected DiscoveryPolicy (0x%x). Run Minimal Discovery Policy\n",
-        __FUNCTION__,
+        __func__,
         DiscoveryPolicy
         ));
       return EFI_SUCCESS;
@@ -884,14 +884,14 @@ BootDiscoveryPolicyHandler (
       DEBUG_INFO,
       "%a - Failed to locate gEfiBootManagerPolicyProtocolGuid."
       "Driver connect will be skipped.\n",
-      __FUNCTION__
+      __func__
       ));
     return Status;
   }
 
   Status = BMPolicy->ConnectDeviceClass (BMPolicy, Class);
   if (EFI_ERROR (Status)) {
-    DEBUG ((DEBUG_ERROR, "%a - ConnectDeviceClass returns - %r\n", __FUNCTION__, Status));
+    DEBUG ((DEBUG_ERROR, "%a - ConnectDeviceClass returns - %r\n", __func__, Status));
     return Status;
   }
 
@@ -1096,7 +1096,7 @@ PlatformBootManagerUnableToBoot (
       DEBUG ((
         DEBUG_WARN,
         "%a: rebooting after refreshing all boot options\n",
-        __FUNCTION__
+        __func__
         ));
       gRT->ResetSystem (EfiResetCold, EFI_SUCCESS, 0, NULL);
     }
diff --git a/ArmPkg/Universal/Smbios/ProcessorSubClassDxe/ProcessorSubClass.c b/ArmPkg/Universal/Smbios/ProcessorSubClassDxe/ProcessorSubClass.c
index 3b12e26abf..9050588500 100644
--- a/ArmPkg/Universal/Smbios/ProcessorSubClassDxe/ProcessorSubClass.c
+++ b/ArmPkg/Universal/Smbios/ProcessorSubClassDxe/ProcessorSubClass.c
@@ -741,7 +741,7 @@ AddSmbiosProcessorTypeTable (
     DEBUG ((
       DEBUG_ERROR,
       "[%a]:[%dL] Smbios Type04 Table Log Failed! %r \n",
-      __FUNCTION__,
+      __func__,
       DEBUG_LINE_NUMBER,
       Status
       ));
diff --git a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type00/MiscBiosVendorFunction.c b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type00/MiscBiosVendorFunction.c
index c9f25b7502..38f3864b16 100644
--- a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type00/MiscBiosVendorFunction.c
+++ b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type00/MiscBiosVendorFunction.c
@@ -287,7 +287,7 @@ SMBIOS_MISC_TABLE_FUNCTION (MiscBiosVendor) {
     DEBUG ((
       DEBUG_ERROR,
       "[%a]:[%dL] Smbios Type00 Table Log Failed! %r \n",
-      __FUNCTION__,
+      __func__,
       DEBUG_LINE_NUMBER,
       Status
       ));
diff --git a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type01/MiscSystemManufacturerFunction.c b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type01/MiscSystemManufacturerFunction.c
index 22fb5eccaa..8867de4815 100644
--- a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type01/MiscSystemManufacturerFunction.c
+++ b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type01/MiscSystemManufacturerFunction.c
@@ -184,7 +184,7 @@ SMBIOS_MISC_TABLE_FUNCTION (MiscSystemManufacturer) {
     DEBUG ((
       DEBUG_ERROR,
       "[%a]:[%dL] Smbios Type01 Table Log Failed! %r \n",
-      __FUNCTION__,
+      __func__,
       DEBUG_LINE_NUMBER,
       Status
       ));
diff --git a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type02/MiscBaseBoardManufacturerFunction.c b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type02/MiscBaseBoardManufacturerFunction.c
index 3441e77988..feb42e6f5d 100644
--- a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type02/MiscBaseBoardManufacturerFunction.c
+++ b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type02/MiscBaseBoardManufacturerFunction.c
@@ -214,7 +214,7 @@ SMBIOS_MISC_TABLE_FUNCTION (MiscBaseBoardManufacturer) {
     DEBUG ((
       DEBUG_ERROR,
       "[%a]:[%dL] Smbios Type02 Table Log Failed! %r \n",
-      __FUNCTION__,
+      __func__,
       DEBUG_LINE_NUMBER,
       Status
       ));
diff --git a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type03/MiscChassisManufacturerFunction.c b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type03/MiscChassisManufacturerFunction.c
index d161970c02..6b3b63b0e8 100644
--- a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type03/MiscChassisManufacturerFunction.c
+++ b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type03/MiscChassisManufacturerFunction.c
@@ -179,7 +179,7 @@ SMBIOS_MISC_TABLE_FUNCTION (MiscChassisManufacturer) {
     DEBUG ((
       DEBUG_ERROR,
       "[%a]:[%dL] Smbios Type03 Table Log Failed! %r \n",
-      __FUNCTION__,
+      __func__,
       DEBUG_LINE_NUMBER,
       Status
       ));
diff --git a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type13/MiscNumberOfInstallableLanguagesFunction.c b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type13/MiscNumberOfInstallableLanguagesFunction.c
index 386b8800e2..951ac2a905 100644
--- a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type13/MiscNumberOfInstallableLanguagesFunction.c
+++ b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type13/MiscNumberOfInstallableLanguagesFunction.c
@@ -161,7 +161,7 @@ SMBIOS_MISC_TABLE_FUNCTION (MiscNumberOfInstallableLanguages) {
     DEBUG ((
       DEBUG_ERROR,
       "[%a]:[%dL] Smbios Type13 Table Log Failed! %r \n",
-      __FUNCTION__,
+      __func__,
       DEBUG_LINE_NUMBER,
       Status
       ));
diff --git a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type32/MiscBootInformationFunction.c b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type32/MiscBootInformationFunction.c
index fdf6262aa7..fa1ea95f2b 100644
--- a/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type32/MiscBootInformationFunction.c
+++ b/ArmPkg/Universal/Smbios/SmbiosMiscDxe/Type32/MiscBootInformationFunction.c
@@ -69,7 +69,7 @@ SMBIOS_MISC_TABLE_FUNCTION (MiscBootInformation) {
     DEBUG ((
       DEBUG_ERROR,
       "[%a]:[%dL] Smbios Type32 Table Log Failed! %r \n",
-      __FUNCTION__,
+      __func__,
       DEBUG_LINE_NUMBER,
       Status
       ));