1 files changed, 9 insertions, 0 deletions

diff --git a/arch/x86/boot/compressed/string.c b/arch/x86/boot/compressed/string.c
index 19b3e693cd72..ffb9c5c9d748 100644
--- a/arch/x86/boot/compressed/string.c
+++ b/arch/x86/boot/compressed/string.c
@@ -1,2 +1,11 @@
 #include "misc.h"
+
+int memcmp(const void *s1, const void *s2, size_t len)
+{
+        u8 diff;
+        asm("repe; cmpsb; setnz %0"
+            : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
+        return diff;
+}
+
 #include "../string.c"