Add support for clock syscalls

arch/x86_64.c

@@ -192,4 +192,53 @@ ssize_t recvfrom(int fd, const void* buf, size_t size, int flags, const void* so
   return nrecv;
 }
 
+#define SYS_CLOCK_SETTIME 227
+int clock_settime(clockid_t clockid, const struct timespec *tp) {
+  int rtn;
+  asm volatile(
+    "syscall\n"
+    : "=a"(rtn)
+    : "a"(SYS_CLOCK_SETTIME), "D"(clockid), "S"(tp)
+    : "rcx", "r11"
+  );
+  return rtn;
+}
+
+#define SYS_CLOCK_GETTIME 228
+int clock_gettime(clockid_t clockid, struct timespec *tp) {
+  int rtn;
+  asm volatile(
+    "syscall\n"
+    : "=a"(rtn)
+    : "a"(SYS_CLOCK_GETTIME), "D"(clockid), "S"(tp)
+    : "rcx", "r11", "memory"
+  );
+  return rtn;
+}
+
+#define SYS_CLOCK_GETRES 229
+int clock_getres(clockid_t clockid, struct timespec *res){
+  int rtn;
+  asm volatile(
+    "syscall\n"
+    : "=a"(rtn)
+    : "a"(SYS_CLOCK_GETRES), "D"(clockid), "S"(res)
+    : "rcx", "r11", "memory"
+  );
+  return rtn;
+}
+
+#define SYS_CLOCK_NANOSLEEP 230
+int clock_nanosleep(clockid_t clockid, int flags, const struct timespec *t, struct timespec* remain){
+  int rtn;
+  asm volatile(
+    "mov %5, %%r10\n"
+    "syscall\n"
+    : "=a"(rtn)
+    : "a"(SYS_CLOCK_NANOSLEEP), "D"(clockid), "S"(flags), "d"(t), "r"(remain)
+    : "rcx", "r11", "memory"
+  );
+  return rtn;
+}
+
 #endif /* ifdef __x86_64__ */