diff --git a/src/StartupInformation.cc b/src/StartupInformation.cc
index 5357f36..6d03adb 100644
--- a/src/StartupInformation.cc
+++ b/src/StartupInformation.cc
@@ -21,4 +21,12 @@ StartupInformation::kernelSize()
     return kernelEnd - kernelStart;
 }
 
+u32
+StartupInformation::memorySize()
+    const
+{
+    // Memory is 1 MiB plus however much upper memory we have.
+    return 1024 * 1024 + multibootInformation->upperMemoryKB() * 1024;
+}
+
 } /* namespace kernel */
diff --git a/src/StartupInformation.hh b/src/StartupInformation.hh
index 77ea7af..cc74c5e 100644
--- a/src/StartupInformation.hh
+++ b/src/StartupInformation.hh
@@ -38,6 +38,9 @@ struct StartupInformation
 
     /** Size of the kernel image in bytes. */
     u32 kernelSize() const;
+
+    /** Size of memory in bytes. */
+    u32 memorySize() const;
 };
 
 } /* namespace kernel */