diff --git a/arm7tdmi/src/simple_memory.rs b/arm7tdmi/src/simple_memory.rs
index 9e63fa1..1037c9b 100644
--- a/arm7tdmi/src/simple_memory.rs
+++ b/arm7tdmi/src/simple_memory.rs
@@ -69,13 +69,13 @@ impl DebugRead for SimpleMemory {
 
 impl MemoryGdbInterface for SimpleMemory {
     fn memory_map_xml(&self, offset: u64, length: usize, buf: &mut [u8]) -> usize {
-        let memory_map = r#"<?xml version="1.0"?>
+        let memory_map = format!(r#"<?xml version="1.0"?>
     <!DOCTYPE memory-map
         PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN"
                 "http://sourceware.org/gdb/gdb-memory-map.dtd">
     <memory-map>
-        <memory type="ram" start="0x0" length="16384"/>
-    </memory-map>"#
+        <memory type="ram" start="0x0" length="{}"/>
+    </memory-map>"#, self.data.len())
             .trim()
             .as_bytes();
         copy_range_to_buf(memory_map, offset, length, buf)