[ion] Move pcbVersion method to its own file

ion/src/device/shared/drivers/Makefile

@@ -16,6 +16,7 @@ ion_device_src += $(addprefix ion/src/device/shared/drivers/, \
   internal_flash.cpp \
   keyboard.cpp \
   led.cpp \
+  pcb_version.cpp \
   power.cpp\
   random.cpp\
   reset.cpp \

ion/src/device/shared/drivers/pcb_version.cpp

@@ -0,0 +1,25 @@
+#include <ion.h>
+#include "board.h"
+
+namespace Ion {
+
+const char * pcbVersion() {
+  constexpr int pcbVersionLength = 5; // xx.yy
+  static char pcbVer[pcbVersionLength] = {'\0'};
+  if (pcbVer[0] == '\0') {
+    Device::Board::PCBVersion ver = Device::Board::pcbVersion();
+    /* As PCB version only uses 4 chars, value should be at most 9999. */
+    assert(ver < 10000);
+    for (int i = pcbVersionLength - 1; i >= 0; i--) {
+      if (i == 2) {
+        pcbVer[i] = '.';
+      } else {
+        pcbVer[i] = '0' + ver % 10;
+        ver /= 10;
+      }
+    }
+  }
+  return pcbVer;
+}
+
+}

ion/src/device/shared/drivers/serial_number.cpp

@@ -15,25 +15,6 @@ const char * serialNumber() {
   return serialNumber;
 }
 
-const char * pcbVersion() {
-  constexpr int pcbVersionLength = 5; // xx.yy
-  static char pcbVer[pcbVersionLength] = {'\0'};
-  if (pcbVer[0] == '\0') {
-    Device::Board::PCBVersion ver = Device::Board::pcbVersion();
-    /* As PCB version only uses 4 chars, value should be at most 9999. */
-    assert(ver < 10000);
-    for (int i = pcbVersionLength - 1; i >= 0; i--) {
-      if (i == 2) {
-        pcbVer[i] = '.';
-      } else {
-        pcbVer[i] = '0' + ver % 10;
-        ver /= 10;
-      }
-    }
-  }
-  return pcbVer;
-}
-
 }
 
 namespace Ion {

ion/src/shared/dummy/pcb_version.cpp

@@ -0,0 +1,5 @@
+#include <ion.h>
+
+const char * Ion::pcbVersion() {
+  return "00.00";
+}

ion/src/shared/dummy/serial_number.cpp

@@ -3,7 +3,3 @@
 const char * Ion::serialNumber() {
   return "000000000000";
 }
-
-const char * Ion::pcbVersion() {
-  return "0.0";
-}

ion/src/simulator/Makefile

@@ -6,6 +6,7 @@ ion_src += $(addprefix ion/src/shared/dummy/, \
   exam_mode.cpp \
   fcc_id.cpp \
   led.cpp \
+  pcb_version.cpp \
   power.cpp \
   serial_number.cpp \
   stack.cpp \