How to scroll down my activity in Android

How to scroll down my activity in Android

Let me explain my problem. I have a layout such as:
<LinearLayout ... > (vertical)
<FixedHeightLayout ... /> (let's say the middle of the whole screen
height)
<ListView ... /> (large list of items)
</LinearLayout>
That is, I have a vertically oriented linear layout with two items: a
fixed height shape and a list view. I do need to be able to scroll down to
the end of the whole activity but not only the list view. The thing is
that I can scroll the list view but I need the fixed height layout to
disappear.
How can I achieve this? Sorry but it's difficult to explain.