diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h
index 21bc633..351f021 100644
--- a/arch/x86/include/asm/e820.h
+++ b/arch/x86/include/asm/e820.h
@@ -23,4 +23,7 @@
 
 #endif /* __ASSEMBLY__ */
 
+/* Implementation defined function to install an e820 map */
+unsigned install_e820_map(unsigned max_entries, struct e820entry *);
+
 #endif /* _ASM_X86_E820_H */