add SPI lib

Author: Neutree

cores/arduino/hal/include/SPI_hal.h

@@ -0,0 +1,12 @@
+
+#ifndef __ARDUINO_SPI_HAL_H
+#define __ARDUINO_SPI_HAL_H
+
+#define SPI_MUTEX_LOCK() 
+#define SPI_MUTEX_UNLOCK() 
+
+
+#endif //__ARDUINO_SPI_HAL_H
+
+
+

libraries/SPI/examples/basic.ino

@@ -0,0 +1,20 @@
+#include "SPI.h"
+
+SPIClass spi0(SPI0);
+
+void setup()
+{
+    spi0.setFrequency(10000000);
+    spi0.begin(27, 26, 28, 29);
+    spi0.transfer(1);
+    spi0.transfer(2);
+    spi0.transfer(3);
+    spi0.transfer(0xEE);
+}
+
+void loop()
+{
+
+}
+
+