1 files changed, 54 insertions, 0 deletions
diff --git a/cores/arduino/HardwareSerial3.cpp b/cores/arduino/HardwareSerial3.cpp
new file mode 100644
index 0000000..012839d
--- /dev/null
+++ b/cores/arduino/HardwareSerial3.cpp
@@ -0,0 +1,54 @@
+#include "Arduino.h"
+#include "HardwareSerial.h"
+
+// Each HardwareSerial is defined in its own file, sine the linker pulls
+// in the entire file when any element inside is used. --gc-sections can
+// additionally cause unused symbols to be dropped, but ISRs have the
+// "used" attribute so are never dropped and they keep the
+// HardwareSerial instance in as well. Putting each instance in its own
+// file prevents the linker from pulling in any unused instances in the
+// first place.
+
+#if defined(HAVE_HWSERIAL3)
+
+#if defined(USART_RX_vect)
+  ISR(USART_RX_vect)
+#elif defined(USART3_RX_vect)
+  ISR(USART3_RX_vect)
+#elif defined(USART_RXC_vect)
+  ISR(USART_RXC_vect) // ATmega8
+#else
+  #error "Don't know what the Data Received vector is called for the first UART"
+#endif
+  {
+    Serial3._rx_complete_irq();
+  }
+
+#if defined(UART3_UDRE_vect)
+ISR(UART3_UDRE_vect)
+#elif defined(UART_UDRE_vect)
+ISR(UART_UDRE_vect)
+#elif defined(USART3_UDRE_vect)
+ISR(USART3_UDRE_vect)
+#elif defined(USART_UDRE_vect)
+ISR(USART_UDRE_vect)
+#else
+  #error "Don't know what the Data Register Empty vector is called for the first UART"
+#endif
+{
+  Serial3._tx_udr_empty_irq();
+}
+
+#if defined(UBRRH) && defined(UBRRL)
+  HardwareSerial Serial3(&UBRRH, &UBRRL, &UCSRA, &UCSRB, &UCSRC, &UDR);
+#else
+  HardwareSerial Serial3(&UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UCSR3C, &UDR3);
+#endif
+
+// Function that can be weakly referenced by serialEventRun to prevent
+// pulling in this file if it's not otherwise used.
+bool Serial3_available() {
+  return Serial3.available();
+}
+
+#endif // HAVE_HWSERIAL3