diff --git a/BOOT/ENVIRON/INC/bootmgr.h b/BOOT/ENVIRON/INC/bootmgr.h
index f255ecb..17e3321 100644
--- a/BOOT/ENVIRON/INC/bootmgr.h
+++ b/BOOT/ENVIRON/INC/bootmgr.h
@@ -92,6 +92,12 @@ typedef struct {
     BOOT_APPLICATION_OPTION Options;
 } BOOT_INPUT_APPLICATION_ENTRY, *PBOOT_INPUT_APPLICATION_ENTRY;
 
+typedef struct {
+    ULONG Attributes;
+    GUID BcdIdentifier;
+    PBOOT_APPLICATION_OPTION Options;
+} BOOT_APPLICATION_ENTRY, *PBOOT_APPLICATION_ENTRY;
+
 #define BOOT_MEMORY_INFO_VERSION 1
 
 typedef struct {
diff --git a/BOOT/ENVIRON/LIB/bootlib.c b/BOOT/ENVIRON/LIB/bootlib.c
index cf9cbf2..56c6925 100644
--- a/BOOT/ENVIRON/LIB/bootlib.c
+++ b/BOOT/ENVIRON/LIB/bootlib.c
@@ -13,6 +13,7 @@ Abstract:
 
 --*/
 
+#include <ntrtl.h>
 #include "bootlib.h"
 
 //
@@ -25,83 +26,9 @@ Abstract:
     sizeof(BOOT_RETURN_DATA) \
     )
 
-ULONG
-BlGetBootOptionListSize (
-    IN PBOOT_APPLICATION_OPTION Options
-    );
-
-ULONG
-BlGetBootOptionSize (
-    IN PBOOT_APPLICATION_OPTION Option
-    )
-
-/*++
-
-Routine Description:
-
-    Gets the size of a boot option.
-
-Arguments:
-
-    Option - the boot option to get the size of.
-
-Return Value:
-
-    The size of the option.
-
---*/
-
-{
-    ULONG TotalSize;
-
-    if (Option->DataOffset != 0) {
-        TotalSize = Option->DataOffset + Option->DataSize;
-    } else {
-        TotalSize = sizeof(BOOT_APPLICATION_OPTION);
-    }
-
-    if (Option->OtherOptionsOffset != 0) {
-        TotalSize += BlGetBootOptionListSize((PBOOT_APPLICATION_OPTION)((PUCHAR)Option + Option->OtherOptionsOffset));
-    }
-
-    return TotalSize;
-}
-
-ULONG
-BlGetBootOptionListSize (
-    IN PBOOT_APPLICATION_OPTION Options
-    )
-
-/*++
-
-Routine Description:
-
-    Gets the total size of a list boot options.
-
-Arguments:
-
-    Options - the boot option list to get the size of.
-
-Return Value:
-
-    The size of the options.
-
---*/
-
-{
-    ULONG TotalSize, NextOffset;
-    PBOOT_APPLICATION_OPTION Option;
-
-    TotalSize = 0;
-    NextOffset = 0;
-    do {
-        Option = (PBOOT_APPLICATION_OPTION)((PUCHAR)Options + NextOffset);
-        NextOffset = Option->NextOptionOffset;
-        TotalSize += BlGetBootOptionSize(Option);
-    } while (NextOffset != 0);
-
-    return TotalSize;
-}
+PBOOT_INPUT_PARAMETERS BlpApplicationParameters;
+BOOT_APPLICATION_ENTRY BlpApplicationEntry;
+PBOOT_DEVICE BlpBootDevice;
 
 NTSTATUS
 InitializeLibrary (
@@ -130,7 +57,6 @@ Return Value:
 {
     NTSTATUS Status;
     PBOOT_INPUT_APPLICATION_ENTRY ApplicationEntry;
-    PBOOT_DEVICE BootDevice;
     PBOOT_FIRMWARE_DATA FirmwareData;
     PBOOT_BLOCK_IDENTIFIER BlockDevice;
     PBOOT_APPLICATION_OPTION Option;
@@ -150,7 +76,7 @@ Return Value:
     // Calculate structure addresses from offsets.
     //
     ApplicationEntry = (PBOOT_INPUT_APPLICATION_ENTRY)((PUCHAR)InputParameters + InputParameters->ApplicationEntryOffset);
-    BootDevice = (PBOOT_DEVICE)((PUCHAR)InputParameters + InputParameters->BootDeviceOffset);
+    BlpBootDevice = (PBOOT_DEVICE)((PUCHAR)InputParameters + InputParameters->BootDeviceOffset);
     FirmwareData = (PBOOT_FIRMWARE_DATA)((PUCHAR)InputParameters + InputParameters->FirmwareDataOffset);
 
     //
@@ -161,6 +87,21 @@ Return Value:
         return Status;
     }
 
+    //
+    // Check application entry signature.
+    //
+    if (ApplicationEntry->Signature != BOOT_INPUT_APPLICATION_ENTRY_SIGNATURE) {
+        return STATUS_INVALID_PARAMETER_9;
+    }
+
+    //
+    // Save input parameters and application entry data.
+    //
+    BlpApplicationParameters = InputParameters;
+    BlpApplicationEntry.Attributes = ApplicationEntry->Attributes;
+    RtlCopyMemory(&BlpApplicationEntry.BcdIdentifier, &ApplicationEntry->BcdIdentifier, sizeof(GUID));
+    BlpApplicationEntry.Options = &ApplicationEntry->Options;
+
     //
     // Print debug information.
     //
@@ -169,18 +110,18 @@ Return Value:
     ConsolePrintf(L"Image size: %x\r\n", InputParameters->ImageSize);
 
     ConsolePrint(L"Boot device type: ");
-    switch (BootDevice->Type) {
+    switch (BlpBootDevice->Type) {
     case BOOT_DEVICE_TYPE_PARTITION:
         ConsolePrint(L"partition\r\n");
-        BlockDevice = &BootDevice->Partition.Parent;
+        BlockDevice = &BlpBootDevice->Partition.Parent;
         break;
     case BOOT_DEVICE_TYPE_PARTITION_EX:
         ConsolePrint(L"partition\r\n");
-        BlockDevice = &BootDevice->PartitionEx.Parent;
+        BlockDevice = &BlpBootDevice->PartitionEx.Parent;
         break;
     default:
         ConsolePrint(L"generic block device\r\n");
-        BlockDevice = &BootDevice->Block;
+        BlockDevice = &BlpBootDevice->Block;
         break;
     }
 
diff --git a/BOOT/ENVIRON/LIB/bootopt.c b/BOOT/ENVIRON/LIB/bootopt.c
new file mode 100644
index 0000000..9865f57
--- /dev/null
+++ b/BOOT/ENVIRON/LIB/bootopt.c
@@ -0,0 +1,89 @@
+/*++
+
+Copyright (c) 2024, Quinn Stephens.
+Provided under the BSD 3-Clause license.
+
+Module Name:
+
+   bootopt.c
+
+Abstract:
+
+   Provides boot option utilities.
+
+--*/
+
+#include "bootlib.h"
+
+ULONG
+BlGetBootOptionSize (
+    IN PBOOT_APPLICATION_OPTION Option
+    )
+
+/*++
+
+Routine Description:
+
+    Gets the size of a boot option.
+
+Arguments:
+
+    Option - the boot option to get the size of.
+
+Return Value:
+
+    The size of the option.
+
+--*/
+
+{
+    ULONG TotalSize;
+
+    if (Option->DataOffset != 0) {
+        TotalSize = Option->DataOffset + Option->DataSize;
+    } else {
+        TotalSize = sizeof(BOOT_APPLICATION_OPTION);
+    }
+
+    if (Option->OtherOptionsOffset != 0) {
+        TotalSize += BlGetBootOptionListSize((PBOOT_APPLICATION_OPTION)((PUCHAR)Option + Option->OtherOptionsOffset));
+    }
+
+    return TotalSize;
+}
+
+ULONG
+BlGetBootOptionListSize (
+    IN PBOOT_APPLICATION_OPTION Options
+    )
+
+/*++
+
+Routine Description:
+
+    Gets the total size of a list boot options.
+
+Arguments:
+
+    Options - the boot option list to get the size of.
+
+Return Value:
+
+    The size of the options.
+
+--*/
+
+{
+    ULONG TotalSize, NextOffset;
+    PBOOT_APPLICATION_OPTION Option;
+
+    TotalSize = 0;
+    NextOffset = 0;
+    do {
+        Option = (PBOOT_APPLICATION_OPTION)((PUCHAR)Options + NextOffset);
+        NextOffset = Option->NextOptionOffset;
+        TotalSize += BlGetBootOptionSize(Option);
+    } while (NextOffset != 0);
+
+    return TotalSize;
+}