Preheat the oven to 180 degrees C. In a medium bowl, mix together 2 cups of flour, icing sugar and butter until it forms a dough, or at least the butter is in small crumbs. Press into the bottom of a 20x30cm baking dish.
Bake for 10 minutes in the preheated oven. While this bakes, whisk together the white sugar, salt, flour and eggs in a large bowl. Stir in rhubarb to coat. Spread evenly over the baked crust when it comes out of the oven.
Bake for another 35 minutes in the preheated oven, or until rhubarb is tender. Cool and cut into squares to serve.