[BOOT:LIB] Add boot option size helpers

BOOT/ENVIRON/INC/bootlib.h

@@ -23,6 +23,16 @@ typedef struct {
     ULONG Flags;
 } BOOT_LIBRARY_PARAMETERS, *PBOOT_LIBRARY_PARAMETERS;
 
+ULONG
+BlGetBootOptionSize (
+    IN PBOOT_APPLICATION_ENTRY_OPTION Option
+    );
+
+ULONG
+BlGetBootOptionListSize (
+    IN PBOOT_APPLICATION_ENTRY_OPTION Options
+    );
+
 NTSTATUS
 BlInitializeLibrary (
     IN PBOOT_INPUT_PARAMETERS InputParameters,

BOOT/ENVIRON/LIB/bootlib.c

@@ -25,6 +25,84 @@ Abstract:
     sizeof(BOOT_RETURN_DATA) \
     )
 
+ULONG
+BlGetBootOptionListSize (
+    IN PBOOT_APPLICATION_ENTRY_OPTION Options
+    );
+
+ULONG
+BlGetBootOptionSize (
+    IN PBOOT_APPLICATION_ENTRY_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_ENTRY_OPTION);
+    }
+
+    if (Option->OtherOptionsOffset != 0) {
+        TotalSize += BlGetBootOptionListSize((PBOOT_APPLICATION_ENTRY_OPTION)((PUCHAR)Option + Option->OtherOptionsOffset));
+    }
+
+    return TotalSize;
+}
+
+ULONG
+BlGetBootOptionListSize (
+    IN PBOOT_APPLICATION_ENTRY_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_ENTRY_OPTION Option;
+
+    TotalSize = 0;
+    NextOffset = 0;
+    do {
+        Option = (PBOOT_APPLICATION_ENTRY_OPTION)((PUCHAR)Options + NextOffset);
+        NextOffset = Option->NextOptionOffset;
+        TotalSize += BlGetBootOptionSize(Option);
+    } while (NextOffset != 0);
+
+    return TotalSize;
+}
+
 NTSTATUS
 InitializeLibrary (
     IN PBOOT_INPUT_PARAMETERS InputParameters,