--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/usr/usys.S	Fri May 26 23:11:05 2017 +0900
@@ -0,0 +1,36 @@
+#include "syscall.h"
+
+#define SYSCALL(name) \
+.globl name; \
+name: \
+	PUSH {r4};\
+	MOV r4, r3;\
+	MOV r3, r2;\
+	MOV r2, r1;\
+	MOV r1, r0;\
+	MOV r0, #SYS_ ## name;\
+	swi 0x00;\
+	POP {r4};\
+	bx lr;
+
+SYSCALL(fork)
+SYSCALL(exit)
+SYSCALL(wait)
+SYSCALL(pipe)
+SYSCALL(read)
+SYSCALL(write)
+SYSCALL(close)
+SYSCALL(kill)
+SYSCALL(exec)
+SYSCALL(open)
+SYSCALL(mknod)
+SYSCALL(unlink)
+SYSCALL(fstat)
+SYSCALL(link)
+SYSCALL(mkdir)
+SYSCALL(chdir)
+SYSCALL(dup)
+SYSCALL(getpid)
+SYSCALL(sbrk)
+SYSCALL(sleep)
+SYSCALL(uptime)