MPS2_AN385 improvements (#1225)

* MPS2_AN385 improvements

Sync various MPS2_AN385 CORTEX-M3 QEMU targets and improve their
Makefiles and cleanup gcc support:
- FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Qemu_mps2:
  - Makefile
    - output image size after linking
    - move -nostartfiles from compiler to linker flags
    - modernize compiler warning flags
    - add --gc-sections to linker flags
  - TCPEchoClient_SingleTasks.c: fix compiler warnings
  - main.c: fix compiler warnings (remove unused code)
  - main_networking.c
    - remove ipLOCAL_MAC_ADDRESS (unknown)
    - fix compiler warnings about unused params
  - startup.c: main(void), remove unused includes,
    silence  unused params
  - syscalls.c: remove unused defines, silence unused params,
    more compact _sbrk()
- FreeRTOS/Demo/CORTEX_MPS2_QEMU_IAR_GCC/build/gcc:
  - Makefile
    - CFLAGS/LDFLAGS in more readable lines
    - move -nostartfiles to linker flags
    - comment out -specs=rdimon.specs as it is not needed
  - startup_gcc.c: fix typo in comment, remove unused uart code
- FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC
  - Makefile
    - after compilation output size of image
    - remove -DQEMU_SOC_MPS2, not needed
    - update many CFLAGS/LDFLAGS settings to more modern gcc/source
    - -ffunction-sections -fdata-sections is moved to CFLAGS
  - startup.c: sync with other ports
  - syscall.c: _write(): param buf is not unused, silence unused params

Signed-off-by: Florian La Roche <Florian.LaRoche@gmail.com>

* remove ipLOCAL_MAC_ADDRESS completely and fix formatting errors

remove ipLOCAL_MAC_ADDRESS completely and fix formatting errors

Signed-off-by: Florian La Roche <Florian.LaRoche@gmail.com>

FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Qemu_mps2/Makefile

@@ -1,4 +1,5 @@
 CC = arm-none-eabi-gcc
+SIZE = arm-none-eabi-size
 BIN := freertos_tcp_mps2_demo.axf
 
 BUILD_DIR := build
@@ -51,30 +52,33 @@ SOURCE_FILES += ${FREERTOS_TCP}/source/portable/BufferManagement/BufferAllocatio
 SOURCE_FILES += ${FREERTOS_TCP}/source/portable/NetworkInterface/MPS2_AN385/NetworkInterface.c
 SOURCE_FILES += ${FREERTOS_TCP}/source/portable/NetworkInterface/MPS2_AN385/ether_lan9118/smsc9220_eth_drv.c
 
-DEFINES := -DQEMU_SOC_MPS2 -DHEAP3
+DEFINES := -DHEAP3
-
+CPPFLAGS += $(DEFINES)
-LDFLAGS = -T mps2_m3.ld -specs=nano.specs --specs=rdimon.specs -lc -lrdimon
-LDFLAGS += -Xlinker -Map=${BUILD_DIR}/output.map
-
-CFLAGS += -nostartfiles -mthumb -mcpu=cortex-m3 -Wno-error=implicit-function-declaration
-CFLAGS += -Wno-builtin-declaration-mismatch -Werror
 
+CFLAGS += -mthumb -mcpu=cortex-m3
 ifeq ($(DEBUG), 1)
-    CFLAGS += -ggdb3 -Og
+    CFLAGS += -g3 -Og -ffunction-sections -fdata-sections
 else
-    CFLAGS += -O3
+    CFLAGS += -Os -ffunction-sections -fdata-sections
 endif
-    CFLAGS += -fstrict-aliasing -Wstrict-aliasing -Wno-error=address-of-packed-member
+CFLAGS += -MMD
+CFLAGS += -Wall -Wextra -Wshadow
+#CFLAGS += -Wpedantic -fanalyzer
+#CFLAGS += -flto
+CFLAGS += $(INCLUDE_DIRS)
+
+LDFLAGS = -T mps2_m3.ld
+LDFLAGS += -Xlinker -Map=${BUILD_DIR}/output.map
+LDFLAGS += -Xlinker --gc-sections
+LDFLAGS += -nostartfiles -specs=nano.specs -specs=nosys.specs -specs=rdimon.specs
 
 OBJ_FILES := $(SOURCE_FILES:%.c=$(BUILD_DIR)/%.o)
 
-CPPFLAGS += $(DEFINES)
-CFLAGS += $(INCLUDE_DIRS)
-
 .PHONY: clean
 
 $(BUILD_DIR)/$(BIN) : $(OBJ_FILES)
-	$(CC) -ffunction-sections -fdata-sections $(CFLAGS) $(LDFLAGS) $+ -o $(@)
+	$(CC) $(CFLAGS) $(LDFLAGS) $+ -o $(@)
+	$(SIZE) $(@)
 
 %.d: %.c
 	@set -e; rm -f $@; \
@@ -87,7 +91,7 @@ INCLUDES := $(SOURCE_FILES:%.c=$(BUILD_DIR)/%.d)
 
 ${BUILD_DIR}/%.o : %.c Makefile
 	-mkdir -p $(@D)
-	$(CC)  $(CPPFLAGS) $(CFLAGS) -MMD -c $< -o $@
+	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
 
 clean:
 	-rm -rf build

FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Qemu_mps2/TCPEchoClient_SingleTasks.c

@@ -206,10 +206,10 @@
                     lStringLength = prvCreateTxData( pcTransmittedString, echoBUFFER_SIZES );
 
                     /* Add in some unique text at the front of the string. */
-                    sprintf( pcTransmittedString, "TxRx message number %u", ulTxCount );
+                    sprintf( pcTransmittedString, "TxRx message number %lu", ulTxCount );
                     ulTxCount++;
 
-                    printf( "sending data to the echo server size %d original %d\n",
+                    printf( "sending data to the echo server size %ld original %d\n",
                             lStringLength,
                             echoBUFFER_SIZES );
                     /* Send the string to the socket. */
@@ -217,7 +217,7 @@
                                                   ( void * ) pcTransmittedString, /* The data being sent. */
                                                   lStringLength,                  /* The length of the data being sent. */
                                                   0 );                            /* No flags. */
-                    printf( "FreeRTOS_send returned...transmitted %d\n",
+                    printf( "FreeRTOS_send returned...transmitted %ld\n",
                             lTransmitted );
 
                     if( lTransmitted < 0 )
@@ -398,15 +398,24 @@
         #if ( ipconfigIPv4_BACKWARD_COMPATIBLE == 1 )
             eDHCPCallbackAnswer_t xApplicationDHCPHook( eDHCPCallbackPhase_t eDHCPPhase,
                                                         uint32_t ulIPAddress )
+            {
+                ( void ) eDHCPPhase;
+                ( void ) ulIPAddress;
+
+                return eDHCPContinue;
+            }
         #else /* ( ipconfigIPv4_BACKWARD_COMPATIBLE == 1 ) */
             eDHCPCallbackAnswer_t xApplicationDHCPHook_Multi( eDHCPCallbackPhase_t eDHCPPhase,
                                                               struct xNetworkEndPoint * pxEndPoint,
                                                               IP_Address_t * pxIPAddress )
+            {
+                ( void ) eDHCPPhase;
+                ( void ) pxEndPoint;
+                ( void ) pxIPAddress;
+
+                return eDHCPContinue;
+            }
         #endif /* ( ipconfigIPv4_BACKWARD_COMPATIBLE == 1 ) */
-        {
-            /* Provide a stub for this function. */
-            return eDHCPContinue;
-        }
 
     #endif /* if ( ipconfigUSE_DHCP_HOOK != 0 )*/
 

FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Qemu_mps2/main.c

@@ -40,9 +40,7 @@ void main_tcp_echo_client_tasks( void );
 void vApplicationIdleHook( void );
 void vApplicationTickHook( void );
 
-extern void initialise_monitor_handles( void );
+int main( void )
-
-int main()
 {
     main_tcp_echo_client_tasks();
     return 0;
@@ -84,8 +82,6 @@ void vApplicationStackOverflowHook( TaskHandle_t pxTask,
 
 void vApplicationIdleHook( void )
 {
-    volatile size_t xFreeHeapSpace;
-
     /* This is just a trivial example of an idle hook.  It is called on each
      * cycle of the idle task.  It must *NOT* attempt to block.  In this case the
      * idle task just queries the amount of FreeRTOS heap that remains.  See the

FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Qemu_mps2/main_networking.c

@@ -180,8 +180,6 @@ void main_tcp_echo_client_tasks( void )
         }
         #endif /* ( ipconfigUSE_DHCP != 0 ) */
 
-        memcpy( ipLOCAL_MAC_ADDRESS, ucMACAddress, sizeof( ucMACAddress ) );
-
         FreeRTOS_IPInit_Multi();
     #else /* if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 ) */
         /* Using the old /single /IPv4 library, or using backward compatible mode of the new /multi library. */
@@ -224,6 +222,10 @@ BaseType_t xTasksAlreadyCreated = pdFALSE;
     uint32_t ulDNSServerAddress;
     char cBuffer[ 16 ];
 
+    #if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 )
+        ( void ) pxEndPoint;
+    #endif /* defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 ) */
+
     /* If the network has just come up...*/
     if( eNetworkEvent == eNetworkUp )
     {
@@ -335,6 +337,10 @@ static void prvMiscInitialisation( void )
     {
         BaseType_t xReturn;
 
+        #if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 )
+            ( void ) pxEndPoint;
+        #endif /* defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 ) */
+
         /* Determine if a name lookup is for this node.  Two names are given
          * to this node: that returned by pcApplicationHostnameHook() and that set
          * by mainDEVICE_NICK_NAME. */

FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Qemu_mps2/startup.c

@@ -28,15 +28,14 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "CMSIS/CMSDK_CM3.h"
-#include "CMSIS/core_cm3.h"
 
 extern void vPortSVCHandler( void );
 extern void xPortPendSVHandler( void );
 extern void xPortSysTickHandler( void );
-extern void uart_init();
+extern void uart_init( void );
-extern int main();
+extern int main( void );
 
+void _start( void );
 void __attribute__( ( weak ) ) EthernetISR( void );
 
 extern uint32_t _estack, _sidata, _sdata, _edata, _sbss, _ebss;
@@ -63,7 +62,6 @@ void Reset_Handler( void )
     }
 
     /* jump to board initialisation */
-    void _start( void );
     _start();
 }
 
@@ -96,6 +94,16 @@ void prvGetRegistersFromStack( uint32_t * pulFaultStackAddress )
     for( ; ; )
     {
     }
+
+    /* Remove the warning about unused variables. */
+    ( void ) r0;
+    ( void ) r1;
+    ( void ) r2;
+    ( void ) r3;
+    ( void ) r12;
+    ( void ) lr;
+    ( void ) pc;
+    ( void ) psr;
 }
 
 static void Default_Handler( void ) __attribute__( ( naked ) );
@@ -114,7 +122,8 @@ void Default_Handler( void )
         "NVIC_INT_CTRL_CONST: .word 0xe000ed04\n"
     );
 }
-static void HardFault_Handler( void ) __attribute__( ( naked ) );
+
+static void Default_Handler2( void ) __attribute__( ( naked ) );
 void Default_Handler2( void )
 {
     __asm volatile
@@ -158,7 +167,7 @@ void Default_Handler6( void )
     }
 }
 
-const uint32_t * isr_vector[] __attribute__( ( section( ".isr_vector" ) ) ) =
+const uint32_t * const isr_vector[] __attribute__( ( section( ".isr_vector" ) ) ) =
 {
     ( uint32_t * ) &_estack,
     ( uint32_t * ) &Reset_Handler,       /* Reset                -15  */
@@ -195,7 +204,7 @@ const uint32_t * isr_vector[] __attribute__( ( section( ".isr_vector" ) ) ) =
 void _start( void )
 {
     uart_init();
-    main( 0, 0 );
+    main();
     exit( 0 );
 }
 
@@ -212,4 +221,6 @@ __attribute__( ( naked ) ) void exit( int status )
         "bkpt 0xab\n"
         "end: b end\n"
         );
+
+    ( void ) status;
 }

FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Qemu_mps2/syscalls.c

@@ -38,24 +38,21 @@ typedef struct UART_t
     volatile uint32_t BAUDDIV;
 } UART_t;
 
-#define UART0_ADDR           ( ( UART_t * ) ( 0x40004000 ) )
+#define UART0_ADDR         ( ( UART_t * ) ( 0x40004000 ) )
 #define UART_DR( baseaddr )    ( *( unsigned int * ) ( baseaddr ) )
 
-#define UART_STATE_TXFULL    ( 1 << 0 )
+#define UART_CTRL_TX_EN    ( 1 << 0 )
-#define UART_CTRL_TX_EN      ( 1 << 0 )
-#define UART_CTRL_RX_EN      ( 1 << 1 )
 
 
 extern unsigned long _heap_bottom;
 extern unsigned long _heap_top;
-extern unsigned long g_ulBase;
 
-static void * heap_end = 0;
+static char * heap_end = ( char * ) &_heap_bottom;
 
 /**
  * @brief initializes the UART emulated hardware
  */
-void uart_init()
+void uart_init( void )
 {
     UART0_ADDR->BAUDDIV = 16;
     UART0_ADDR->CTRL = UART_CTRL_TX_EN;
@@ -68,6 +65,7 @@ void uart_init()
  */
 int _fstat( int file )
 {
+    ( void ) file;
     return 0;
 }
 
@@ -80,6 +78,9 @@ int _read( int file,
            char * buf,
            int len )
 {
+    ( void ) file;
+    ( void ) buf;
+    ( void ) len;
     return -1;
 }
 
@@ -97,6 +98,8 @@ int _write( int file,
 {
     int todo;
 
+    ( void ) file;
+
     for( todo = 0; todo < len; todo++ )
     {
         UART_DR( UART0_ADDR ) = *buf++;
@@ -113,16 +116,9 @@ int _write( int file,
  */
 void * _sbrk( int incr )
 {
-    char * prev_heap_end;
+    void * prev_heap_end = heap_end;
 
-    if( heap_end == 0 )
+    if( ( heap_end + incr ) > ( char * ) &_heap_top )
-    {
-        heap_end = ( void * ) &_heap_bottom;
-    }
-
-    prev_heap_end = heap_end;
-
-    if( ( heap_end + incr ) > ( void * ) &_heap_top )
     {
         return ( void * ) -1;
     }

FreeRTOS/Demo/CORTEX_MPS2_QEMU_IAR_GCC/build/gcc/Makefile

@@ -9,13 +9,20 @@ LD = arm-none-eabi-gcc
 SIZE = arm-none-eabi-size
 MAKE = make
 
-
+CFLAGS += -ffreestanding -mthumb -mcpu=cortex-m3
-CFLAGS += $(INCLUDE_DIRS) -nostartfiles -ffreestanding -mthumb -mcpu=cortex-m3 \
+CFLAGS += -Wall -Wextra -Wshadow
-		  -Wall -Wextra -g3 -Os -ffunction-sections -fdata-sections \
+CFLAGS += -g3 -Os -ffunction-sections -fdata-sections
-		  -MMD -MP -MF"$(@:%.o=%.d)" -MT $@
+CFLAGS += -MMD -MP -MF"$(@:%.o=%.d)" -MT $@
-
+#CFLAGS += -std=c99
-#CFLAGS += -Wpedantic -Wshadow -fanalyzer
+#CFLAGS += -Wpedantic -fanalyzer
 #CFLAGS += -flto
+CFLAGS += $(INCLUDE_DIRS)
+
+LDFLAGS = -T ./mps2_m3.ld
+LDFLAGS += -Xlinker -Map=$(OUTPUT_DIR)/RTOSDemo.map
+LDFLAGS += -Xlinker --gc-sections
+LDFLAGS += -nostartfiles
+LDFLAGS += -specs=nano.specs -specs=nosys.specs # -specs=rdimon.specs
 
 #
 # Kernel build.
@@ -106,9 +113,7 @@ $(IMAGE): ./mps2_m3.ld $(OBJS_OUTPUT) Makefile
 	@echo ""
 	@echo "--- Final linking ---"
 	@echo ""
-	$(LD) $(OBJS_OUTPUT) $(CFLAGS) -Xlinker --gc-sections -Xlinker -T ./mps2_m3.ld \
+	$(LD) $(CFLAGS) $(LDFLAGS) $(OBJS_OUTPUT) -o $(IMAGE)
-		-Xlinker -Map=$(OUTPUT_DIR)/RTOSDemo.map -specs=nano.specs \
-		-specs=nosys.specs -specs=rdimon.specs -o $(IMAGE)
 	$(SIZE) $(IMAGE)
 
 $(DEP_OUTPUT):

FreeRTOS/Demo/CORTEX_MPS2_QEMU_IAR_GCC/build/gcc/startup_gcc.c

@@ -27,22 +27,6 @@
 #include <stdint.h>
 #include <stdio.h>
 
-/* UART peripheral register addresses and bits. */
-#define UART0_ADDR             ( ( UART_t * ) ( 0x40004000 ) )
-#define UART_DR( baseaddr )    ( *( uint32_t * ) ( baseaddr ) )
-#define UART_STATE( baseaddr ) ( *( uint32_t * ) ( baseaddr + 4 ) )
-#define UART_STATE_TXFULL      ( 1 << 0 )
-
-typedef struct UART_t
-{
-    volatile uint32_t DATA;
-    volatile uint32_t STATE;
-    volatile uint32_t CTRL;
-    volatile uint32_t INTSTATUS;
-    volatile uint32_t BAUDDIV;
-} UART_t;
-
-
 /* FreeRTOS interrupt handlers. */
 extern void vPortSVCHandler( void );
 extern void xPortPendSVHandler( void );
@@ -99,7 +83,7 @@ void Reset_Handler( void )
 }
 
 /* Variables used to store the value of registers at the time a hardfault
- * occurs.  These are volatile to try and prevent the compiler/linker optimising
+ * occurs.  These are volatile to try and prevent the compiler/linker optimizing
  * them away as the variables never actually get used. */
 volatile uint32_t r0;
 volatile uint32_t r1;

FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/Makefile

@@ -1,4 +1,5 @@
 CC                     =    arm-none-eabi-gcc
+SIZE                   =    arm-none-eabi-size
 BIN                   :=    RTOSDemo.axf
 
 BUILD_DIR             :=    build
@@ -34,33 +35,23 @@ INCLUDE_DIRS          +=    -I$(FREERTOS_DIR)/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/C
 INCLUDE_DIRS          +=    -I$(KERNEL_DIR)/include
 INCLUDE_DIRS          +=    -I$(KERNEL_DIR)/portable/GCC/ARM_CM3_MPU
 
-DEFINES               :=    -DQEMU_SOC_MPS2
 DEFINES               :=    -DHEAP4
-
 CPPFLAGS              +=    $(DEFINES)
 
-CFLAGS                +=    -mcpu=cortex-m3
+CFLAGS                +=    -mthumb -mcpu=cortex-m3
-CFLAGS                +=    -Wno-error=implicit-function-declaration
+CFLAGS                +=    -Wall -Wextra -Wshadow -Wno-unused-parameter
-CFLAGS                +=    -Wno-builtin-declaration-mismatch
+#CFLAGS                +=    -Wpedantic -fanalyzer
-CFLAGS                +=    -Werror
-CFLAGS                +=    -Wall
-CFLAGS                +=    -Wextra
-CFLAGS                +=    -fstrict-aliasing
-CFLAGS                +=    -Wstrict-aliasing
-CFLAGS                +=    -Wno-error=address-of-packed-member
-CFLAGS                +=    -Wno-unused-parameter
 CFLAGS                +=    $(INCLUDE_DIRS)
 
 LDFLAGS                =    -T ./scripts/mps2_m3.ld
-LDFLAGS               +=    -mthumb
-
 LDFLAGS               +=    -Xlinker -Map=${BUILD_DIR}/output.map
+LDFLAGS               +=    -Xlinker --gc-sections
 LDFLAGS               +=    -nostartfiles -nostdlib -nolibc -nodefaultlibs
 
 ifeq ($(DEBUG), 1)
-    CFLAGS                +=     -ggdb3 -Og -save-temps=obj
+    CFLAGS                +=     -g3 -Og -ffunction-sections -fdata-sections -save-temps=obj
 else
-    CFLAGS                +=     -O3
+    CFLAGS                +=     -Os -ffunction-sections -fdata-sections
 endif
 
 ifeq ($(PICOLIBC), 1)
@@ -73,7 +64,8 @@ OBJ_FILES             :=    $(SOURCE_FILES:%.c=$(BUILD_DIR)/%.o)
 .PHONY: clean
 
 $(BUILD_DIR)/$(BIN) : $(OBJ_FILES)
-	$(CC) -ffunction-sections -fdata-sections $(LDFLAGS) $+ -o $(@)
+	$(CC) $(CFLAGS) $(LDFLAGS) $+ -o $(@)
+	$(SIZE) $(@)
 
 %.d: %.c
 	@set -e; rm -f $@; \

FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/init/startup.c

@@ -35,7 +35,9 @@ extern void vPortSVCHandler( void );
 extern void xPortPendSVHandler( void );
 extern void xPortSysTickHandler( void );
 extern void uart_init( void );
-extern int main();
+extern int main( void );
+
+void _start( void );
 
 extern uint32_t _estack, _sidata, _sdata, _edata, _sbss, _ebss;
 
@@ -61,13 +63,12 @@ void Reset_Handler( void )
     }
 
     /* jump to board initialisation */
-    void _start( void );
     _start();
 }
 
 void prvGetRegistersFromStack( uint32_t * pulFaultStackAddress )
 {
-/* These are volatile to try and prevent the compiler/linker optimising them
+/* These are volatile to try and prevent the compiler/linker optimizing them
  * away as the variables never actually get used.  If the debugger won't show the
  * values of the variables, make them global my moving their declaration outside
  * of this function. */
@@ -122,6 +123,7 @@ void Default_Handler( void )
         "NVIC_INT_CTRL_CONST: .word 0xe000ed04\n"
     );
 }
+
 static void HardFault_Handler( void ) __attribute__( ( naked ) );
 void HardFault_Handler( void )
 {
@@ -232,12 +234,12 @@ const uint32_t * const isr_vector[] __attribute__( ( section( ".isr_vector" ) )
 void _start( void )
 {
     uart_init();
-    main( 0, 0 );
+    main();
     exit( 0 );
 }
 
 __attribute__( ( naked ) )
-void exit( __attribute__( ( unused ) ) int status )
+void exit( int status )
 {
     /* Force qemu to exit using ARM Semihosting */
     __asm volatile (
@@ -250,4 +252,6 @@ void exit( __attribute__( ( unused ) ) int status )
         "bkpt 0xab\n"
         "end: b end\n"
         );
+
+    ( void ) status;
 }

FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/main.c

@@ -37,7 +37,7 @@
 void vApplicationIdleHook( void );
 void vApplicationTickHook( void );
 
-int main()
+int main( void )
 {
     app_main();
     return 0;

FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/syscall.c

@@ -69,7 +69,7 @@ void uart_init(void)
 int
 _uart_putc(char c, FILE *file)
 {
-    (void) file;
+    ( void ) file;
     UART_DR( UART0_ADDR ) = c;
     return (unsigned char) c;
 }
@@ -90,8 +90,9 @@ static char * heap_end = ( char * ) &_heap_bottom;
  * @todo  implement if necessary
  *
  */
-int _fstat( __attribute__( ( unused ) ) int file )
+int _fstat( int file )
 {
+    ( void ) file;
     return 0;
 }
 
@@ -100,10 +101,13 @@ int _fstat( __attribute__( ( unused ) ) int file )
  * @todo  implement if necessary
  *
  */
-int _read( __attribute__( ( unused ) ) int file,
+int _read( int file,
-           __attribute__( ( unused ) ) char * buf,
+           char * buf,
-           __attribute__( ( unused ) ) int len )
+           int len )
 {
+    ( void ) file;
+    ( void ) buf;
+    ( void ) len;
     return -1;
 }
 
@@ -115,12 +119,14 @@ int _read( __attribute__( ( unused ) ) int file,
  * @param [in] len   length of the buffer
  * @returns the number of bytes written
  */
-int _write( __attribute__( ( unused ) ) int file,
+int _write( int file,
-            __attribute__( ( unused ) ) char * buf,
+            char * buf,
             int len )
 {
     int todo;
 
+    ( void ) file;
+
     for( todo = 0; todo < len; todo++ )
     {
         UART_DR( UART0_ADDR ) = *buf++;