diff --git a/module_dfu/src/dfu.xc b/module_dfu/src/dfu.xc
index 7ec7ff62..28f0e88c 100644
--- a/module_dfu/src/dfu.xc
+++ b/module_dfu/src/dfu.xc
@@ -357,7 +357,7 @@ int DFUReportResetState(chanend ?c_user_cmd)
     return inDFU;
 }
 
-int XMOS_DFU_RevertFactory(chanend ?c_user_cmd) 
+static int XMOS_DFU_RevertFactory(chanend ?c_user_cmd)
 {
     unsigned s = 0;
 
@@ -371,7 +371,7 @@ int XMOS_DFU_RevertFactory(chanend ?c_user_cmd)
     return 0;
 }
 
-int XMOS_DFU_SelectImage(unsigned int index, chanend ?c_user_cmd)
+static int XMOS_DFU_SelectImage(unsigned int index, chanend ?c_user_cmd)
 {
     // Select the image index for firmware update
     // Currently not used or implemented
@@ -379,12 +379,12 @@ int XMOS_DFU_SelectImage(unsigned int index, chanend ?c_user_cmd)
 }
 
 
-int XMOS_DFU_SaveState()
+static int XMOS_DFU_SaveState()
 { 
     return 0;
 }
 
-int XMOS_DFU_LoadState()
+static int XMOS_DFU_LoadState()
 {
     return 0;
 }
diff --git a/module_usb_audio/audio.xc b/module_usb_audio/audio.xc
index e1e9a94c..72b8674f 100755
--- a/module_usb_audio/audio.xc
+++ b/module_usb_audio/audio.xc
@@ -142,7 +142,7 @@ static inline void doI2SClocks(unsigned divide)
 
 /* I2S delivery thread */
 #pragma unsafe arrays
-{unsigned, unsigned} deliver(chanend c_out, chanend ?c_spd_out, unsigned divide, unsigned curSamFreq, chanend ?c_dig_rx, chanend ?c_adc)
+{unsigned, unsigned} static deliver(chanend c_out, chanend ?c_spd_out, unsigned divide, unsigned curSamFreq, chanend ?c_dig_rx, chanend ?c_adc)
 {
 	unsigned sample;
     unsigned underflow = 0;
@@ -734,7 +734,7 @@ static inline void doI2SClocks(unsigned divide)
 
 /* This function is a dummy version of the deliver thread that does not 
    connect to the codec ports. It is used during DFU reset. */
-{unsigned,unsigned} dummy_deliver(chanend c_out) 
+{unsigned,unsigned} static dummy_deliver(chanend c_out)
 {
     while (1)
     {
diff --git a/module_usb_audio/clocking/clockgen.xc b/module_usb_audio/clocking/clockgen.xc
index 3da5ea1c..c0269298 100644
--- a/module_usb_audio/clocking/clockgen.xc
+++ b/module_usb_audio/clocking/clockgen.xc
@@ -38,13 +38,13 @@ static int clockValid[NUM_CLOCKS];                          /* Store current val
 static int clockInt[NUM_CLOCKS];                            /* Interupt flag for clocks */
 static int clockId[NUM_CLOCKS];
 
-int abs(int x) 
+static int abs(int x)
 {
     if (x < 0) return -x;
     return x;
 }
 
-int channelContainsControlToken(chanend x)
+static int channelContainsControlToken(chanend x)
 {
     unsigned char tmpc;
 
@@ -58,7 +58,7 @@ int channelContainsControlToken(chanend x)
 
 }
 
-void outInterrupt(chanend c_interruptControl, int value) 
+static void outInterrupt(chanend c_interruptControl, int value)
 {
     /* Non-blocking check for control token */
     //if (channelContainsControlToken(c_interruptControl)) 
diff --git a/module_usb_audio/endpoint0/audiorequests.xc b/module_usb_audio/endpoint0/audiorequests.xc
index eb2c3f70..596def14 100644
--- a/module_usb_audio/endpoint0/audiorequests.xc
+++ b/module_usb_audio/endpoint0/audiorequests.xc
@@ -54,7 +54,7 @@ unsigned int g_curSamFreq48000Family = DEFAULT_FREQ % 48000 == 0;
 unsigned int g_curSamFreqMultiplier = DEFAULT_FREQ / 48000;
 
 /* Store an int into a char array: Note this allows non-word aligned access unlike reinerpret cast */
-void storeInt(unsigned char buffer[], int index, int val)
+static void storeInt(unsigned char buffer[], int index, int val)
 {
     buffer[index+3] = val>>24;
     buffer[index+2] = val>>16;
@@ -63,13 +63,13 @@ void storeInt(unsigned char buffer[], int index, int val)
 }
 
 /* Store an short into a char array: Note this allows non-word aligned access unlike reinerpret cast */
-void storeShort(unsigned char buffer[], int index, short val)
+static void storeShort(unsigned char buffer[], int index, short val)
 {
     buffer[index+1] = val>>8;
     buffer[index]  =  val;
 }
 
-void storeFreq(unsigned char buffer[], int &i, int freq)
+static void storeFreq(unsigned char buffer[], int &i, int freq)
 {
     storeInt(buffer, i, freq);
     i+=4;
@@ -81,7 +81,7 @@ void storeFreq(unsigned char buffer[], int &i, int freq)
 }
 
 
-unsigned longMul(unsigned a, unsigned b, int prec) 
+static unsigned longMul(unsigned a, unsigned b, int prec)
 {
     unsigned x,y;
     unsigned ret;
@@ -94,12 +94,12 @@ unsigned longMul(unsigned a, unsigned b, int prec)
     return ret;
 }
 
-void setG_curSamFreqMultiplier(int x) {
+static void setG_curSamFreqMultiplier(int x) {
     asm(" stw %0, dp[g_curSamFreqMultiplier]" :: "r"(x));
 }
 
 /* Update master volume i.e. i.e update weights for all channels */
-void updateMasterVol( int unitID, chanend ?c_mix_ctl)
+static void updateMasterVol( int unitID, chanend ?c_mix_ctl)
 {
     int x;
 #ifndef OUT_VOLUME_IN_MIXER
@@ -168,7 +168,7 @@ void updateMasterVol( int unitID, chanend ?c_mix_ctl)
     }
 }  
 
-void updateVol(int unitID, int channel, chanend ?c_mix_ctl)
+static void updateVol(int unitID, int channel, chanend ?c_mix_ctl)
 {   
     int x;
 #ifndef OUT_VOLUME_IN_MIXER
diff --git a/module_usb_audio/mixer/mixer.xc b/module_usb_audio/mixer/mixer.xc
index 4fe9726e..6b2c841c 100644
--- a/module_usb_audio/mixer/mixer.xc
+++ b/module_usb_audio/mixer/mixer.xc
@@ -114,7 +114,7 @@ int doMix8(xc_ptr samples, xc_ptr mult);
 /* DO NOT inline, causes 10.4.2 tools to add extra loads in loop */
 /* At 18 x 12dB we could get 64 x bigger */
 #pragma unsafe arrays
-int doMix(xc_ptr samples, xc_ptr ptr, xc_ptr mult)
+static int doMix(xc_ptr samples, xc_ptr ptr, xc_ptr mult)
 {
     int h=0; 
     int l=0; 
@@ -150,7 +150,7 @@ int doMix(xc_ptr samples, xc_ptr ptr, xc_ptr mult)
 #endif
 
 #pragma unsafe arrays
-void giveSamplesToHost(chanend c, xc_ptr samples, xc_ptr ptr, xc_ptr multIn)
+static void giveSamplesToHost(chanend c, xc_ptr samples, xc_ptr ptr, xc_ptr multIn)
 {
 #if defined(IN_VOLUME_IN_MIXER) && defined(IN_VOLUME_AFTER_MIX)
     int mult;
@@ -221,7 +221,7 @@ static void getSamplesFromHost(chanend c, xc_ptr samples, int base, unsigned und
 }
 
 #pragma unsafe arrays
-void giveSamplesToDevice(chanend c, xc_ptr samples, xc_ptr ptr, xc_ptr multOut, unsigned underflow)
+static void giveSamplesToDevice(chanend c, xc_ptr samples, xc_ptr ptr, xc_ptr multOut, unsigned underflow)
 {
 
     outuint(c, underflow);
@@ -255,7 +255,7 @@ void giveSamplesToDevice(chanend c, xc_ptr samples, xc_ptr ptr, xc_ptr multOut,
 }
 
 #pragma unsafe arrays
-void getSamplesFromDevice(chanend c, xc_ptr samples, int base)
+static void getSamplesFromDevice(chanend c, xc_ptr samples, int base)
 {
 #if defined(IN_VOLUME_IN_MIXER) && !defined(IN_VOLUME_AFTER_MIX)
     int mult;
@@ -288,10 +288,10 @@ void getSamplesFromDevice(chanend c, xc_ptr samples, int base)
   }
 }
 
-int mixer1_mix2_flag = (DEFAULT_FREQ > 96000);
+static int mixer1_mix2_flag = (DEFAULT_FREQ > 96000);
 
 #pragma unsafe arrays
-void mixer1(chanend c_host, chanend c_mix_ctl, chanend c_mixer2)
+static void mixer1(chanend c_host, chanend c_mix_ctl, chanend c_mixer2)
 {
     int mixed;
     unsigned cmd;
@@ -520,11 +520,11 @@ void mixer1(chanend c_host, chanend c_mix_ctl, chanend c_mixer2)
     }
 }
 
-int mixer2_mix2_flag = (DEFAULT_FREQ > 96000);
+static int mixer2_mix2_flag = (DEFAULT_FREQ > 96000);
 
 #if (MAX_MIX_COUNT > 0) 
 #pragma unsafe arrays
-void mixer2(chanend c_mixer1, chanend c_audio)
+static void mixer2(chanend c_mixer1, chanend c_audio)
 {
   int mixed;
 
diff --git a/module_usb_audio/usb_buffer/decouple.xc b/module_usb_audio/usb_buffer/decouple.xc
index 5f545ae4..9ebf6d2f 100644
--- a/module_usb_audio/usb_buffer/decouple.xc
+++ b/module_usb_audio/usb_buffer/decouple.xc
@@ -105,7 +105,7 @@ int slotSize = 3;    /* 3 bytes per sample for Audio Class 1.0 */
 
 #pragma select handler
 #pragma unsafe arrays
-void handle_audio_request(chanend c_mix_out) 
+void handle_audio_request(chanend c_mix_out)
 {
     int outSamps;
     int space_left;
@@ -472,7 +472,7 @@ unsigned g_intFlag = 0;
 
 extern unsigned char g_intData[8];
 
-void check_for_interrupt(chanend ?c_clk_int) {
+static void check_for_interrupt(chanend ?c_clk_int) {
     unsigned tmp;
 
     select
diff --git a/module_usb_midi/src/midiinparse.xc b/module_usb_midi/src/midiinparse.xc
index ed651e2a..dd7dcf1f 100644
--- a/module_usb_midi/src/midiinparse.xc
+++ b/module_usb_midi/src/midiinparse.xc
@@ -42,7 +42,7 @@ void reset_midi_state(struct midi_in_parse_state &mips) {
  * @brief Construct USB MIDI event 
  *
  */
-unsigned makeEvent(unsigned cable_number, unsigned codeIndexNumber, unsigned midi0, unsigned midi1, unsigned midi2) {
+static unsigned makeEvent(unsigned cable_number, unsigned codeIndexNumber, unsigned midi0, unsigned midi1, unsigned midi2) {
     unsigned event = (cable_number << 28);
     event |= (codeIndexNumber << 24);
     event |= (midi0 << 16);