Add dummy controll flow demo

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/Makefile

@@ -63,12 +63,18 @@ ifeq ($(INCREASING_DEMO), 1)
     SOURCE_FILES += main_increasing.c
 
     CFLAGS := -DmainCREATE_INCREASING_DEMO=1
+else
+ifeq ($(1CHAR_DEMO), 1)
+    SOURCE_FILES += main_1char.c
+
+    CFLAGS := -DmainCREATE_1CHAR_DEMO=1
 else
     SOURCE_FILES += main_blinky.c
 
     CFLAGS := -DmainCREATE_SIMPLE_BLINKY_DEMO_ONLY=1
 endif
 endif
+endif
 
 DEFINES :=  -DQEMU_SOC_MPS2 -DHEAP3
 
@@ -81,7 +87,7 @@ CFLAGS += -Wno-builtin-declaration-mismatch -Werror
 ifeq ($(DEBUG), 1)
     CFLAGS += -ggdb3 -Og
 else
-    CFLAGS += -O3
+    CFLAGS += -O0
 endif
     CFLAGS += -fstrict-aliasing -Wstrict-aliasing -Wno-error=address-of-packed-member
 

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/main.c

@@ -67,6 +67,10 @@ int main()
         {
             main_increasing();
         }
+    #elif ( mainCREATE_1CHAR_DEMO == 1 )
+        {
+            main_increasing();
+        }
     #else
         {
             #error "Invalid Selection...\nPlease Select a Demo application from the main command"

FreeRTOS/Demo/CORTEX_M3_MPS2_QEMU_GCC/main_1char.c

@@ -0,0 +1,136 @@
+/*
+ * FreeRTOS V202111.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+#include <FreeRTOS.h>
+#include <task.h>
+#include <queue.h>
+#include <stdio.h>
+
+__attribute__((noinline)) static void trigger_Qemu_break( void )
+{
+    puts("Trigger");
+}
+static void prvQueueReceiveTask( void * pvParameters );
+static void prvQueueSendTask( void * pvParameters );
+
+#define mainQUEUE_RECEIVE_TASK_PRIORITY    ( tskIDLE_PRIORITY + 2 )
+#define mainQUEUE_SEND_TASK_PRIORITY       ( tskIDLE_PRIORITY + 1 )
+#define mainQUEUE_LENGTH                   ( 1 )
+#define mainQUEUE_SEND_FREQUENCY_MS        ( 10 / portTICK_PERIOD_MS )
+/* The queue used by both tasks. */
+static QueueHandle_t xQueue = NULL;
+static volatile int i;
+
+int inc(void) {
+    i++;
+    return i;
+}
+
+volatile unsigned char FUZZ_INPUT[4096] = {33};
+void main_increasing( void )
+{
+
+
+    if ((FUZZ_INPUT[0] % 4) == 0) {
+        // puts("inc1 mod 4");
+        inc();
+    }
+    if (FUZZ_INPUT[0] >= 42) {
+        // puts("inc2 >= 42");
+        inc();
+    }
+    if (FUZZ_INPUT[0] <= 44) {
+        // puts("inc3 <= 44");
+        inc();
+    }
+    printf("Value of i: %d\n",i);
+
+    trigger_Qemu_break();
+
+
+    /* If all is well, the scheduler will now be running, and the following
+     * line will never be reached.  If the following line does execute, then
+     * there was insufficient FreeRTOS heap memory available for the Idle and/or
+     * timer tasks to be created.  See the memory management section on the
+     * FreeRTOS web site for more details on the FreeRTOS heap
+     * http://www.freertos.org/a00111.html. */
+    for( ; ; )
+    {
+    }
+}
+
+volatile uint32_t FUZZ_LENGTH = 32;
+
+volatile unsigned char last_value = 32; // ascii space
+
+static void prvQueueSendTask( void * pvParameters )
+{
+    unsigned char ulValueToSend = 0;
+    /* Remove compiler warning about unused parameter. */
+    ( void ) pvParameters;
+
+    for(int i=0; i<FUZZ_LENGTH; i++)
+    {
+        ulValueToSend = FUZZ_INPUT[i];
+        if (ulValueToSend > last_value & ulValueToSend >= 33 & ulValueToSend < 127)
+        {
+            // printf("send: %c\n",ulValueToSend);
+            last_value = ulValueToSend;
+            xQueueSend( xQueue, &ulValueToSend, portMAX_DELAY );
+        }
+    }
+    // since priority of this task is lower we only reach this after the Recieve Task is done.
+    trigger_Qemu_break();
+}
+
+
+volatile uint32_t ulRxEvents = 0;
+volatile uint32_t agg = 0;
+static void prvQueueReceiveTask( void * pvParameters )
+{
+    unsigned char ulReceivedValue = 0;
+
+    /* Remove compiler warning about unused parameter. */
+    ( void ) pvParameters;
+
+    for( ; ; )
+    {
+        /* Wait until something arrives in the queue - this task will block
+         * indefinitely provided INCLUDE_vTaskSuspend is set to 1 in
+         * FreeRTOSConfig.h. */
+        xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY );
+
+        //Some computation which depends on the value recieved
+        int t = 0;
+        for (int i=1; i<ulReceivedValue; i++)
+        {
+            t+=i;
+        }
+        agg+=t;
+        // printf("recieved: %u, result: %u\n",ulReceivedValue,t);
+    }
+}
+/*-----------------------------------------------------------*/