Made linker emit a warning whenever common symbols are merged. Fixed some variables having an unnecessary global scope and being subject to common linkage

cross_arm.txt

@@ -29,6 +29,7 @@ c_link_args = [
                '-mfpu=fpv4-sp-d16',
                '-Wl,--gc-sections',
                '-Wl,-Map,main.map',
+               '-Wl,--warn-common',
                '-nostdlib',
                '-Wl,--start-group',
                '-lc',

platform/drivers/GPS/GPS_MDx.c

@@ -32,7 +32,6 @@ char  *dataBuf;
 bool   receiving = false;
 
 OS_FLAG_GRP sentenceReady;
-OS_ERR err;
 
 #ifdef PLATFORM_MD3x0
 #define PORT USART3
@@ -76,6 +75,7 @@ void __attribute__((used)) USART1_IRQHandler()
         if((receiving == false) && (bufPos != 0))
         {
             uint8_t flag = (bufPos < maxPos) ? 0x01 : 0x02;
+            OS_ERR err;
             OSFlagPost(&sentenceReady, flag, OS_OPT_POST_FLAG_SET, &err);
         }
     }
@@ -112,11 +112,13 @@ void gps_init(const uint16_t baud)
     NVIC_SetPriority(USART1_IRQn, 14);
     #endif
 
+    OS_ERR err;
     OSFlagCreate(&sentenceReady, "", 0, &err);
 }
 
 void gps_terminate()
 {
+    OS_ERR err;
     OSFlagDel(&sentenceReady, OS_OPT_DEL_NO_PEND, &err);
     gps_disable();
 
@@ -190,6 +192,7 @@ int gps_getNmeaSentence(char *buf, const size_t maxLength)
     NVIC_EnableIRQ(USART1_IRQn);
     #endif
 
+    OS_ERR err;
     OS_FLAGS status = OSFlagPend(&sentenceReady, 0x03, 0,
                                  OS_OPT_PEND_FLAG_SET_ANY |
                                  OS_OPT_PEND_FLAG_CONSUME |

platform/drivers/display/HX8353_MDx.c

@@ -90,10 +90,11 @@
  */
 static uint16_t frameBuffer[SCREEN_WIDTH * SCREEN_HEIGHT];
 OS_FLAG_GRP renderCompleted;
-OS_ERR err;
 
 void __attribute__((used)) DMA2_Stream7_IRQHandler()
 {
+    OS_ERR err;
+
     OSIntEnter();
     DMA2->HIFCR |= DMA_HIFCR_CTCIF7 | DMA_HIFCR_CTEIF7;    /* Clear flags */
     gpio_setPin(LCD_CS);
@@ -114,6 +115,7 @@ static inline __attribute__((__always_inline__)) void writeData(uint8_t val)
 void display_init()
 {
     /* Create flag for render completion wait */
+    OS_ERR err;
     OSFlagCreate(&renderCompleted, "", 0, &err);
 
     /* Clear framebuffer, setting all pixels to 0xFFFF makes the screen white */
@@ -419,6 +421,7 @@ void display_init()
 
 void display_terminate()
 {
+    OS_ERR err;
     OSFlagDel(&renderCompleted, OS_OPT_DEL_NO_PEND, &err);
 
     /* Shut off FSMC and deallocate framebuffer */
@@ -486,6 +489,7 @@ void display_renderRows(uint8_t startRow, uint8_t endRow)
                      | DMA_SxCR_TEIE          /* Transfer error interrupt    */
                      | DMA_SxCR_EN;           /* Start transfer              */
 
+    OS_ERR err;
     OSFlagPend(&renderCompleted, 0x01, 0, OS_OPT_PEND_FLAG_SET_ANY |
                                           OS_OPT_PEND_FLAG_CONSUME |
                                           OS_OPT_PEND_BLOCKING, NULL, &err);