I don't believe that's directly possible, but you can allocate as many pages as you need and chain them together. To do this calculate how many pages you need by dividing by 4KB, and in a loop allocate a block and add the return address of the allocated block to a list. You can then combine all of your memory into a table of values by looping over the list and adding the 1000 values (taking the start address and adding 4 each time, 1000 times) to the table for each address. If you don't understand, I can code that for you - it's pretty simple to do.
Though I wonder what you're writing to memory that takes so much space? An image or save code, or something?