diff --git a/lib/strcpy.S b/lib/strcpy.S
index 147e2eb..abd1a40 100644
--- a/lib/strcpy.S
+++ b/lib/strcpy.S
@@ -1,23 +1,17 @@
     .intel_syntax noprefix
 
-    .globl _start
-
     .text
 
-
-# String-copying routine.
-# Commented-out lines would also return the starting address of the destination address.
+# String-copying routine. Strings should be null-terminated.
+# Input: rdi = source string base, rsi = destination string base
+# No check is done for buffer overflow.
 strcpy:
-#    push rsi
-.loop:
     movb r10b, [rdi]
     cmpb r10b, 0
     je .end
     movb [rsi], r10b
     inc rdi
     inc rsi
-    jmp .loop
+    jmp strcpy
 .end:
-#    pop rax
     ret
-