USB: Add basic USB sample

samples/usb/Makefile

@@ -0,0 +1,5 @@
+XBE_TITLE = nxdk\ sample\ -\ usb
+GEN_XISO = $(XBE_TITLE).iso
+SRCS = $(CURDIR)/main.c
+NXDK_DIR = $(CURDIR)/../..
+include $(NXDK_DIR)/Makefile

samples/usb/main.c

@@ -0,0 +1,38 @@
+#include <hal/debug.h>
+#include <hal/video.h>
+#include <windows.h>
+#include <usbh_lib.h>
+
+/*
+ * This demo will initialise the usb stack, detect events on the usb ports
+ * and print the device PID and VID.
+*/
+void device_connection_callback(UDEV_T *udev, int status)
+{
+    debugPrint("Device connected on port %u (PID: %04x VID: %04x)\n", udev->port_num,
+                                                                      udev->descriptor.idProduct,
+                                                                      udev->descriptor.idVendor);
+}
+
+void device_disconnect_callback(UDEV_T *udev, int status)
+{
+     debugPrint("Device disconnected on port %u (PID: %04x VID: %04x)\n", udev->port_num,
+                                                                          udev->descriptor.idProduct,
+                                                                          udev->descriptor.idVendor);
+}
+
+int main(void)
+{
+    XVideoSetMode(640, 480, 32, REFRESH_DEFAULT);
+
+    usbh_core_init();
+    usbh_install_conn_callback(&device_connection_callback, &device_disconnect_callback);
+    debugPrint("== ochi usb test ==\n");
+    debugPrint("== Plug and unplug USB devices to test ==\n");
+    while (1) {
+        usbh_pooling_hubs();
+        Sleep(1);
+    }
+    usbh_core_deinit();
+    return 0;
+}