diff --git a/src/io.c b/src/io.c
index 1b35f71..52e5d04 100644
--- a/src/io.c
+++ b/src/io.c
@@ -1,22 +1,21 @@
 #include "io.h"
 
-
 void outb(ushort port, uchar val)
 {
-	asm volatile("outb %1, %0" : : "dN" (port), "a" (val));
+	asm volatile("outb %1, %0" : : "dN"(port), "a"(val));
 }
 
 uchar inb(ushort port)
 {
 	uchar ret;
-	asm volatile("inb %1, %0" : "=a" (ret) : "dN" (port));
+	asm volatile("inb %1, %0" : "=a"(ret) : "dN"(port));
 	return ret;
 }
 
 ushort inw(ushort port)
 {
 	ushort ret;
-	asm volatile("inw %1, %0" : "=a" (ret) : "dN" (port));
+	asm volatile("inw %1, %0" : "=a"(ret) : "dN"(port));
 	return ret;
 }
 
@@ -26,6 +25,7 @@
 	{
 		((uchar *)s)[i] = c;
 	}
+	return s;
 }
 
 void *memcpy(void *dest, const void *src, size_t n)
@@ -34,9 +34,10 @@
 	{
 		((uchar *)dest)[i] = ((uchar *)src)[i];
 	}
+	return dest;
 }
 
 void io_wait()
 {
-	asm volatile("outb %0, $0x80" :: "a"(0));
+	asm volatile("outb %0, $0x80" ::"a"(0));
 }