add libs

lib_gpio/examples/app_gpio_flashing_leds/src/main.xc

@@ -0,0 +1,29 @@
+// Copyright 2014-2021 XMOS LIMITED.
+// This Software is subject to the terms of the XMOS Public Licence: Version 1.
+#include <xs1.h>
+#include <gpio.h>
+
+port p_led1 = XS1_PORT_1A;
+port p_led2 = XS1_PORT_1B;
+
+void flash_leds(client output_gpio_if led1, client output_gpio_if led2)
+{
+  while (1) {
+    led1.output(1);
+    led2.output(0);
+    delay_milliseconds(200);
+    led1.output(0);
+    led2.output(1);
+    delay_milliseconds(200);
+  }
+}
+
+int main() {
+  interface output_gpio_if i_led1[1], i_led2[1];
+  par {
+    output_gpio(i_led1, 1, p_led1, null);
+    output_gpio(i_led2, 1, p_led2, null);
+    flash_leds(i_led1[0], i_led2[0]);
+  }
+  return 0;
+}