diff --git a/docs/05 - Steps to work with FreeRTOS b/docs/05 - Steps to work with FreeRTOS
new file mode 100644
index 0000000..b629c19
--- /dev/null
+++ b/docs/05 - Steps to work with FreeRTOS	
@@ -0,0 +1,7 @@
+1) clone the repository
+2) Inside /esh clone the freeRTOS kernel source code : https://github.com/FreeRTOS/FreeRTOS-Kernel
+3) Disable the configAssert of port.c in freeRTOS kernel Code (For the given example of GCC/ARM3/port.c Line 370)
+4) make
+5) make run
+
+This will start two tasks concurrently one to run shell and other to periodically print a statement
diff --git a/examples/emulation/freertos/FreeRTOSConfig.h b/examples/emulation/freertos/FreeRTOSConfig.h
new file mode 100644
index 0000000..98a42a3
--- /dev/null
+++ b/examples/emulation/freertos/FreeRTOSConfig.h
@@ -0,0 +1,189 @@
+/*
+ * FreeRTOS V202212.01
+ * 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
+ *
+ */
+
+#ifndef FREERTOS_CONFIG_H
+#define FREERTOS_CONFIG_H
+
+/*-----------------------------------------------------------
+ * Application specific definitions.
+ *
+ * These definitions should be adjusted for your particular hardware and
+ * application requirements.
+ *
+ * THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
+ * FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
+ *
+ * See http://www.freertos.org/a00110.html
+ *----------------------------------------------------------*/
+
+#define configUSE_TRACE_FACILITY 0
+#define configGENERATE_RUN_TIME_STATS 0
+
+#define configUSE_TICKLESS_IDLE         0
+#define configUSE_PREEMPTION			1
+#define configUSE_IDLE_HOOK				0
+#define configUSE_TICK_HOOK				1
+#define configCPU_CLOCK_HZ				( ( unsigned long ) 25000000 )
+#define configTICK_RATE_HZ				( ( TickType_t ) 1000 )
+#define configMINIMAL_STACK_SIZE		( ( unsigned short ) 80 )
+#define configTOTAL_HEAP_SIZE			( ( size_t ) ( 60 * 1024 ) )
+#define configMAX_TASK_NAME_LEN			( 12 )
+#define configUSE_16_BIT_TICKS			0
+#define configIDLE_SHOULD_YIELD			0
+#define configUSE_MUTEXES				1
+#define configUSE_RECURSIVE_MUTEXES		1
+#define configCHECK_FOR_STACK_OVERFLOW	2
+#define configUSE_MALLOC_FAILED_HOOK	1
+#define configUSE_QUEUE_SETS			1
+#define configUSE_COUNTING_SEMAPHORES	1
+
+#define configMAX_PRIORITIES			( 9UL )
+#define configQUEUE_REGISTRY_SIZE		10
+#define configSUPPORT_STATIC_ALLOCATION	1
+
+/* Timer related defines. */
+#define configUSE_TIMERS				1
+#define configTIMER_TASK_PRIORITY		( configMAX_PRIORITIES - 4 )
+#define configTIMER_QUEUE_LENGTH		20
+#define configTIMER_TASK_STACK_DEPTH	( configMINIMAL_STACK_SIZE * 2 )
+
+#define configUSE_TASK_NOTIFICATIONS	1
+#define configTASK_NOTIFICATION_ARRAY_ENTRIES 3
+
+/* Set the following definitions to 1 to include the API function, or zero
+to exclude the API function. */
+
+#define INCLUDE_vTaskPrioritySet				1
+#define INCLUDE_uxTaskPriorityGet				1
+#define INCLUDE_vTaskDelete						1
+#define INCLUDE_vTaskCleanUpResources			0
+#define INCLUDE_vTaskSuspend					1
+#define INCLUDE_vTaskDelayUntil					1
+#define INCLUDE_vTaskDelay						1
+#define INCLUDE_uxTaskGetStackHighWaterMark		1
+#define INCLUDE_xTaskGetSchedulerState			1
+#define INCLUDE_xTimerGetTimerDaemonTaskHandle	1
+#define INCLUDE_xTaskGetIdleTaskHandle			1
+#define INCLUDE_xSemaphoreGetMutexHolder		1
+#define INCLUDE_eTaskGetState					1
+#define INCLUDE_xTimerPendFunctionCall			1
+#define INCLUDE_xTaskAbortDelay					1
+#define INCLUDE_xTaskGetHandle					1
+
+/* This demo makes use of one or more example stats formatting functions.  These
+format the raw data provided by the uxTaskGetSystemState() function in to human
+readable ASCII form.  See the notes in the implementation of vTaskList() within
+FreeRTOS/Source/tasks.c for limitations. */
+#define configUSE_STATS_FORMATTING_FUNCTIONS	0
+
+#define configKERNEL_INTERRUPT_PRIORITY 		( 255 )	/* All eight bits as QEMU doesn't model the priority bits. */
+/* !!!! configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to zero !!!!
+See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html. */
+#define configMAX_SYSCALL_INTERRUPT_PRIORITY 	( 191 )
+
+/* Use the Cortex-M3 optimised task selection rather than the generic C code
+version. */
+#define configUSE_PORT_OPTIMISED_TASK_SELECTION 1
+
+/* The Win32 target is capable of running all the tests tasks at the same
+ * time. */
+#define configRUN_ADDITIONAL_TESTS				1
+
+/* The test that checks the trigger level on stream buffers requires an
+allowable margin of error on slower processors (slower than the Win32
+machine on which the test is developed). */
+#define configSTREAM_BUFFER_TRIGGER_LEVEL_TEST_MARGIN   4
+
+#ifndef __IASMARM__ /* Prevent C code being included in IAR asm files. */
+	void vAssertCalled( const char *pcFileName, uint32_t ulLine );
+	#define configASSERT( x ) if( ( x ) == 0 ) vAssertCalled( __FILE__, __LINE__ );
+#endif
+
+#define intqHIGHER_PRIORITY		( configMAX_PRIORITIES - 5 )
+#define bktPRIMARY_PRIORITY		( configMAX_PRIORITIES - 3 )
+#define bktSECONDARY_PRIORITY	( configMAX_PRIORITIES - 4 )
+
+#endif /* FREERTOS_CONFIG_H */
+
+// #define configUSE_MALLOC_FAILED_HOOK              0
+// #define configUSE_MUTEXES                         1
+// #define configUSE_RECURSIVE_MUTEXES               1
+// #define configUSE_TIMERS                          1
+// #define configTIMER_TASK_STACK_DEPTH              ( configMINIMAL_STACK_SIZE * 2 )
+
+// #define INCLUDE_vTaskPrioritySet                  1
+// #define INCLUDE_uxTaskPriorityGet                 1
+// #define INCLUDE_vTaskDelete                       1
+// #define INCLUDE_vTaskCleanUpResources             0
+// #define INCLUDE_vTaskSuspend                      1
+// #define INCLUDE_vTaskDelayUntil                   1
+// #define INCLUDE_vTaskDelay                        1
+// #define INCLUDE_uxTaskGetStackHighWaterMark       1
+// #define INCLUDE_uxTaskGetStackHighWaterMark2      1
+// #define INCLUDE_xTaskGetSchedulerState            1
+// #define INCLUDE_xTimerGetTimerDaemonTaskHandle    1
+// #define INCLUDE_xTaskGetIdleTaskHandle            1
+// #define INCLUDE_xTaskGetHandle                    1
+// #define INCLUDE_eTaskGetState                     1
+// #define INCLUDE_xSemaphoreGetMutexHolder          1
+// #define INCLUDE_xTimerPendFunctionCall            1
+// #define INCLUDE_xTaskAbortDelay                   1
+
+// #define projCOVERAGE_TEST                         0
+// #define configKERNEL_INTERRUPT_PRIORITY           255
+// #define configMAX_SYSCALL_INTERRUPT_PRIORITY      191 /* equivalent to 0xa0, or priority 5. */
+// #define configMAC_INTERRUPT_PRIORITY              5
+
+
+// #define configASSERT_DEFINED                             1
+// extern void vAssertCalled( void );
+// #define configASSERT( x )    if( ( x ) == 0 ) vAssertCalled()
+// #define configQUEUE_REGISTRY_SIZE                        20
+
+// #define configUSE_PREEMPTION                             1
+// #define configUSE_TIME_SLICING                           0
+// #define configUSE_PORT_OPTIMISED_TASK_SELECTION          0
+
+// #define configUSE_IDLE_HOOK                              0
+// #define configUSE_TICK_HOOK                              0
+// #define configUSE_DAEMON_TASK_STARTUP_HOOK               0
+// #define configCPU_CLOCK_HZ                               ( ( unsigned long ) 25000000 )
+// #define configTICK_RATE_HZ                               ( ( TickType_t ) 10000 )
+// #define configMINIMAL_STACK_SIZE                         ( ( unsigned short ) 2000 )
+// #define configTOTAL_HEAP_SIZE                            ( ( size_t ) ( 80 * 1024 ) )
+// #define configMAX_TASK_NAME_LEN                          ( 10 )
+// #define configUSE_TRACE_FACILITY                         1
+// #define configUSE_16_BIT_TICKS                           0
+// #define configIDLE_SHOULD_YIELD                          1
+
+// #define configMAX_PRIORITIES                             ( 10 )
+// #define configTIMER_QUEUE_LENGTH                         20
+// #define configTIMER_TASK_PRIORITY                        ( configMAX_PRIORITIES - 1 )
+// #define configUSE_COUNTING_SEMAPHORES                    1
+// #define configSUPPORT_DYNAMIC_ALLOCATION                 1
+// #define configSUPPORT_STATIC_ALLOCATION                  0
+// #define configNUM_TX_DESCRIPTORS                         15
+// #define configSTREAM_BUFFER_TRIGGER_LEVEL_TEST_MARGIN    2
\ No newline at end of file
diff --git a/examples/emulation/freertos/Makefile b/examples/emulation/freertos/Makefile
new file mode 100644
index 0000000..d93f254
--- /dev/null
+++ b/examples/emulation/freertos/Makefile
@@ -0,0 +1,79 @@
+#
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# NOTE: the toolchain can be installed using -
+# sudo apt install -y gcc-arm-none-eabi
+
+TOOLCHAIN_PREFIX ?= arm-none-eabi-
+OPTIMIZATION     = g	
+
+EXTERN_SRC = ../../../../FreeRTOS-Kernel
+SRC_C += ../../../../FreeRTOS-Kernel/portable/GCC/ARM_CM3/port.c
+SRC_C += ../../../../FreeRTOS-Kernel/portable/MemMang/heap_4.c
+IGNORE_SRC_PATH += ../../../../FreeRTOS-Kernel/examples
+IGNORE_SRC_PATH += ../../../../FreeRTOS-Kernel/portable
+IGNORE_HEADER_PATH += ../../../../FreeRTOS-Kernel/portable
+IGNORE_HEADER_PATH += ../../../../FreeRTOS-Kernel/examples
+INCLUDES += -I../../../../FreeRTOS-Kernel/include
+INCLUDES += -I../../../../FreeRTOS-Kernel/portable/GCC/ARM_CM3/
+TOOLCHAIN_VERSION := $(shell $(TOOLCHAIN_PREFIX)gcc -dumpversion)
+LIB_GCC_PATH = /usr/lib/gcc/arm-none-eabi/$(TOOLCHAIN_VERSION)/thumb/v7-m/nofp/
+
+DEFINES = -mcpu=cortex-m3 -mthumb
+ASM_FLAGS = -march=armv7-m
+LD_FLAGS = -lgcc -L$(LIB_GCC_PATH)
+
+STARTUP = cortex-m
+
+# MANDATORY:
+#     These 3 parameters are needed for every port
+#     Provide all values in hex
+ROM_BASE_PHYSICAL  = 0x00000000
+ROM_SIZE           = 0x3FFFF
+
+RAM_BASE_PHYSICAL  = 0x20000000
+RAM_SIZE           = 0x7FFFFF
+
+# to reduce binary size, set to 1
+# SHELL_LITE = 0
+
+# setting the stack start manually for m class processors
+DEFINES += -DSTACK_START=0x0003FFFF
+DEFINES += -DSHELL_NO_PRINTF_LL
+
+# MANDATORY:
+#     Provide relative path to shell/ from current directory
+#     Only Variable should be set above this line
+SHELL_ROOT=../../../shell
+-include $(SHELL_ROOT)/Makefile
+# ^^ Do not move the above line. All user targets to be defined below this line!
+
+# ------------------------ User targets below this line ------------------------
+### run: Launches QEMU and loads the project binary on it
+run: $(PROJECT).elf
+	@echo "Use Ctrl+A X to exit Qemu"
+	@qemu-system-arm -M mps2-an385 -cpu cortex-m3 -nographic \
+	 -kernel $(PROJECT).elf
+### debug: Qemu with GDB server. To be executed before 'make gdb'
+debug:
+	@echo Please use \"make gdb\" in another terminal to attach gdb.
+	@echo Use \"cltr+a,x\" to quit qemu debug
+	@qemu-system-arm -S -M mps2-an385 -cpu cortex-m3 -nographic -kernel \
+	 $(PROJECT).elf -gdb tcp::1234
+
+### gdb: Launches GDB and connects to qemu. To be executed after 'make debug'
+gdb:
+	@gdb-multiarch shell.elf -ex "target remote localhost:1234"
diff --git a/examples/emulation/freertos/hello.c b/examples/emulation/freertos/hello.c
new file mode 100644
index 0000000..5817feb
--- /dev/null
+++ b/examples/emulation/freertos/hello.c
@@ -0,0 +1,41 @@
+/**
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+/*
+ * This is a mandatory include.
+ * This has the ADD_CMD() macro
+ */
+#include "shell.h"
+
+/*
+ * There can be one or many function with same prototype, exposed as
+ * a command on the shell. They can be in same or multiple files.
+ */
+int hello(int argc, char** argv) {
+  for (int i = 0; i < argc; i++) {
+    printf(argv[i]);
+    printf(" ");
+  }
+
+  printf("\nPress ctrl + a, x to exit !\n");
+  return 0;
+}
+
+/*
+ * One or many such can exist per file.
+ * Description: ADD_CMD(command, help string, function to be exposed)
+ */
+ADD_CMD(hello, "Echoes the commandline\n\tusage: hello <any string>", hello);
diff --git a/examples/emulation/freertos/platform/platform.c b/examples/emulation/freertos/platform/platform.c
new file mode 100644
index 0000000..25f9021
--- /dev/null
+++ b/examples/emulation/freertos/platform/platform.c
@@ -0,0 +1,239 @@
+/**
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+#include <stdio.h>
+#include "FreeRTOS.h"
+#include "task.h"
+#include "timers.h"
+#include "queue.h"
+#include "shell.h"
+#include <stdbool.h>
+
+#include "shell_config.h"
+#include "string.h"
+#include "shell.h"
+#include "uart.h"
+
+/**
+ * @brief Inilialize the platform
+ *
+ */
+static void vTaskRunShell(void *pvParameters);
+static void vTaskRunShell2(void *pvParameters);
+extern void prompt();
+extern void shell1();
+// extern void vApplicationTickHook(void);
+void vApplicationMallocFailedHook( void )
+{
+	/* vApplicationMallocFailedHook() will only be called if
+	configUSE_MALLOC_FAILED_HOOK is set to 1 in FreeRTOSConfig.h.  It is a hook
+	function that will get called if a call to pvPortMalloc() fails.
+	pvPortMalloc() is called internally by the kernel whenever a task, queue,
+	timer or semaphore is created using the dynamic allocation (as opposed to
+	static allocation) option.  It is also called by various parts of the
+	demo application.  If heap_1.c, heap_2.c or heap_4.c is being used, then the
+	size of the	heap available to pvPortMalloc() is defined by
+	configTOTAL_HEAP_SIZE in FreeRTOSConfig.h, and the xPortGetFreeHeapSize()
+	API function can be used to query the size of free heap space that remains
+	(although it does not provide information on how the remaining heap might be
+	fragmented).  See http://www.freertos.org/a00111.html for more
+	information. */
+	printf( "\r\n\r\nMalloc failed\r\n" );
+	portDISABLE_INTERRUPTS();
+	for( ;; );
+}
+/*-----------------------------------------------------------*/
+
+void vApplicationIdleHook( void )
+{
+	/* vApplicationIdleHook() will only be called if configUSE_IDLE_HOOK is set
+	to 1 in FreeRTOSConfig.h.  It will be called on each iteration of the idle
+	task.  It is essential that code added to this hook function never attempts
+	to block in any way (for example, call xQueueReceive() with a block time
+	specified, or call vTaskDelay()).  If application tasks make use of the
+	vTaskDelete() API function to delete themselves then it is also important
+	that vApplicationIdleHook() is permitted to return to its calling function,
+	because it is the responsibility of the idle task to clean up memory
+	allocated by the kernel to any task that has since deleted itself. */
+}
+/*-----------------------------------------------------------*/
+
+void vApplicationStackOverflowHook( TaskHandle_t pxTask, char *pcTaskName )
+{
+	( void ) pcTaskName;
+	( void ) pxTask;
+
+	/* Run time stack overflow checking is performed if
+	configCHECK_FOR_STACK_OVERFLOW is defined to 1 or 2.  This hook
+	function is called if a stack overflow is detected. */
+	printf( "\r\n\r\nStack overflow in %s\r\n", pcTaskName );
+	portDISABLE_INTERRUPTS();
+	for( ;; );
+}
+/*-----------------------------------------------------------*/
+
+void vApplicationTickHook( void )
+{
+	/* This function will be called by each tick interrupt if
+	configUSE_TICK_HOOK is set to 1 in FreeRTOSConfig.h.  User code can be
+	added here, but the tick hook is called from an interrupt context, so
+	code must not attempt to block, and only the interrupt safe FreeRTOS API
+	functions can be used (those that end in FromISR()). */
+
+	// #if ( mainCREATE_SIMPLE_BLINKY_DEMO_ONLY != 1 )
+	// {
+	// 	extern void vFullDemoTickHookFunction( void );
+
+	// 	vFullDemoTickHookFunction();
+	// }
+	// #endif /* mainCREATE_SIMPLE_BLINKY_DEMO_ONLY */
+}
+/*-----------------------------------------------------------*/
+
+void vApplicationDaemonTaskStartupHook( void )
+{
+	/* This function will be called once only, when the daemon task starts to
+	execute (sometimes called the timer task).  This is useful if the
+	application includes initialisation code that would benefit from executing
+	after the scheduler has been started. */
+}
+/*-----------------------------------------------------------*/
+
+void vAssertCalled( const char *pcFileName, uint32_t ulLine )
+{
+volatile uint32_t ulSetToNonZeroInDebuggerToContinue = 0;
+
+	/* Called if an assertion passed to configASSERT() fails.  See
+	http://www.freertos.org/a00110.html#configASSERT for more information. */
+
+	printf( "ASSERT! Line %d, file %s\r\n", ( int ) ulLine, pcFileName );
+
+ 	taskENTER_CRITICAL();
+	{
+		/* You can step out of this function to debug the assertion by using
+		the debugger to set ulSetToNonZeroInDebuggerToContinue to a non-zero
+		value. */
+		while( ulSetToNonZeroInDebuggerToContinue == 0 )
+		{
+			__asm volatile( "NOP" );
+			__asm volatile( "NOP" );
+		}
+	}
+	taskEXIT_CRITICAL();
+}
+/*-----------------------------------------------------------*/
+
+/* configUSE_STATIC_ALLOCATION is set to 1, so the application must provide an
+implementation of vApplicationGetIdleTaskMemory() to provide the memory that is
+used by the Idle task. */
+void vApplicationGetIdleTaskMemory( StaticTask_t **ppxIdleTaskTCBBuffer, StackType_t **ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize )
+{
+/* If the buffers to be provided to the Idle task are declared inside this
+function then they must be declared static - otherwise they will be allocated on
+the stack and so not exists after this function exits. */
+static StaticTask_t xIdleTaskTCB;
+static StackType_t uxIdleTaskStack[ configMINIMAL_STACK_SIZE ];
+
+	/* Pass out a pointer to the StaticTask_t structure in which the Idle task's
+	state will be stored. */
+	*ppxIdleTaskTCBBuffer = &xIdleTaskTCB;
+
+	/* Pass out the array that will be used as the Idle task's stack. */
+	*ppxIdleTaskStackBuffer = uxIdleTaskStack;
+
+	/* Pass out the size of the array pointed to by *ppxIdleTaskStackBuffer.
+	Note that, as the array is necessarily of type StackType_t,
+	configMINIMAL_STACK_SIZE is specified in words, not bytes. */
+	*pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;
+}
+/*-----------------------------------------------------------*/
+
+/* configUSE_STATIC_ALLOCATION and configUSE_TIMERS are both set to 1, so the
+application must provide an implementation of vApplicationGetTimerTaskMemory()
+to provide the memory that is used by the Timer service task. */
+void vApplicationGetTimerTaskMemory( StaticTask_t **ppxTimerTaskTCBBuffer, StackType_t **ppxTimerTaskStackBuffer, uint32_t *pulTimerTaskStackSize )
+{
+/* If the buffers to be provided to the Timer task are declared inside this
+function then they must be declared static - otherwise they will be allocated on
+the stack and so not exists after this function exits. */
+static StaticTask_t xTimerTaskTCB;
+static StackType_t uxTimerTaskStack[ configTIMER_TASK_STACK_DEPTH ];
+
+	/* Pass out a pointer to the StaticTask_t structure in which the Timer
+	task's state will be stored. */
+	*ppxTimerTaskTCBBuffer = &xTimerTaskTCB;
+
+	/* Pass out the array that will be used as the Timer task's stack. */
+	*ppxTimerTaskStackBuffer = uxTimerTaskStack;
+
+	/* Pass out the size of the array pointed to by *ppxTimerTaskStackBuffer.
+	Note that, as the array is necessarily of type StackType_t,
+	configMINIMAL_STACK_SIZE is specified in words, not bytes. */
+	*pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;
+}
+/*-----------------------------------------------------------*/
+
+void main_blinky1(void)
+{ 
+    //   platform_init();
+    prompt();
+    xTaskCreate(vTaskRunShell, "ShellTask", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL);
+	xTaskCreate(vTaskRunShell2, "ShellTask", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL);
+    vTaskStartScheduler();
+}
+
+static void vTaskRunShell(void *pvParameters)
+{
+    (void)pvParameters;
+	for( ;; )
+     {
+         /* Simply toggle the LED every 500ms, blocking between each toggle. */
+        shell1();
+		// printf("task1\n");
+		// vTaskDelay( xDelay );
+
+     }
+
+
+}
+void platform_init() {
+
+  uart_init();
+  set_read_char(ugetc);
+  set_write_char(uputc);
+}
+static void vTaskRunShell2(void *pvParameters)
+{
+    // (void)pvParameters;
+
+    // printf("hello");
+	const TickType_t xDelay = 7000 / portTICK_PERIOD_MS;
+	for( ;; )
+     {
+         /* Simply toggle the LED every 500ms, blocking between each toggle. */
+        //  shell1();
+        // vTaskDelay( xDelay );
+		printf("task2\n");
+		printf("#");
+		vTaskDelay( xDelay );
+     }
+	
+}
+// int bootFreeRTOS(){
+//     xTaskCreate(vTaskRunShell2, "ShellTask2", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL);
+//     vTaskStartScheduler();
+//     return 0;
+// }
+// ADD_CMD(bootFreeRTOS,"ABCD",bootFreeRTOS);
\ No newline at end of file
diff --git a/examples/emulation/freertos/platform/uart/uart.c b/examples/emulation/freertos/platform/uart/uart.c
new file mode 100644
index 0000000..048d28c
--- /dev/null
+++ b/examples/emulation/freertos/platform/uart/uart.c
@@ -0,0 +1,46 @@
+/**
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+#include "uart.h"
+
+/**
+ * @brief Default UART implementation in case the user hasn't provided
+ *        putc(), get(), uart_init() implementation.
+ *
+ */
+#define UART_DR *((unsigned int *)(UART_BASE + 0x00))
+#define UART_STATE *((unsigned int *)(UART_BASE + 0x04))
+#define UART_CTRL *((unsigned int *)(UART_BASE + 0x08))
+#define UART_INT *((unsigned int *)(UART_BASE + 0x04))
+
+void uputc(char c) {
+  while (UART_STATE & 1)
+    ;
+
+  UART_DR = c;
+}
+
+int ugetc(void) {
+  if (UART_STATE & (1 << 1)) return UART_DR;
+
+  return -1;
+}
+
+void uart_init(void) {
+  UART_CTRL = 0x0;
+  UART_INT = 0xF;
+  UART_CTRL = 0x3;
+}
diff --git a/examples/emulation/freertos/platform/uart/uart.h b/examples/emulation/freertos/platform/uart/uart.h
new file mode 100644
index 0000000..8a89129
--- /dev/null
+++ b/examples/emulation/freertos/platform/uart/uart.h
@@ -0,0 +1,42 @@
+/**
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+#ifndef __UART_H__
+#define __UART_H__
+
+#define UART_BASE 0x40004000
+
+/**
+ * @brief Put a character on uart data buffer
+ *
+ * @param c byte to be sent out
+ */
+void uputc(char c);
+
+/**
+ * @brief Get a character from uart data buffer
+ *
+ * @return int byte read from the uart data register
+ */
+int ugetc(void);
+
+/**
+ * @brief Init the uart, set baud etc
+ *
+ */
+void uart_init(void);
+
+#endif
diff --git a/examples/emulation/freertos/platform/vector_table.c b/examples/emulation/freertos/platform/vector_table.c
new file mode 100644
index 0000000..4cb6c44
--- /dev/null
+++ b/examples/emulation/freertos/platform/vector_table.c
@@ -0,0 +1,101 @@
+/**
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+#include <stdint.h>
+extern void vPortSVCHandler( void );
+extern void xPortPendSVHandler(void);
+extern void xPortSysTickHandler(void);
+#define ISR_HANDLER(x) ((uint32_t)&x)
+
+extern void reset_handler(void);
+
+void default_handler(void) {
+  while (1)
+    ;
+}
+
+uint32_t vector_table[240] __attribute__((section(".init_vector"))) = {
+    (uint32_t)STACK_START, ISR_HANDLER(reset_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(vPortSVCHandler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), 0, 0, 0, 0,     ISR_HANDLER(vPortSVCHandler),      
+    ISR_HANDLER(default_handler), 0,  ISR_HANDLER(xPortPendSVHandler),  ISR_HANDLER(xPortSysTickHandler),
+    // 132 IRQs
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler),
+    ISR_HANDLER(default_handler), ISR_HANDLER(default_handler)};
diff --git a/shell/Makefile b/shell/Makefile
index 68c4583..d24eb99 100644
--- a/shell/Makefile
+++ b/shell/Makefile
@@ -146,7 +146,7 @@ $(BUILD_PATH)/%.o:%.S $(DEP_HEADERS)
 	@$(OBJCOPY) -O binary $< $@ $(PRINT_ONLY_ERRORS)
 	@echo "Done!" $(PRINT_ONLY_ERRORS)
 
-## default target
+## default targetf
 .DEFAULT_GOAL := all
 
 ### all: Builds the project binary. Same as just executing make.
diff --git a/shell/build-magic/find-headers.mk b/shell/build-magic/find-headers.mk
index fe22506..8092db4 100644
--- a/shell/build-magic/find-headers.mk
+++ b/shell/build-magic/find-headers.mk
@@ -33,6 +33,6 @@ H_FILES		= $(filter-out $(IGNORE_H), $(ALL_H_FILES))
 HPP_FILES	= $(filter-out $(IGNORE_HPP), $(ALL_HPP_FILES))
 
 # final list of include paths!
-INCLUDES = $(shell dirname $(H_FILES) $(HPP_FILES) \
+INCLUDES += $(shell dirname $(H_FILES) $(HPP_FILES) \
 			sort | uniq | \
 			while read line; do echo "-I"$$line; done;)
diff --git a/shell/build-magic/find-source.mk b/shell/build-magic/find-source.mk
index b06efa1..cf4508e 100644
--- a/shell/build-magic/find-source.mk
+++ b/shell/build-magic/find-source.mk
@@ -27,7 +27,7 @@ IGNORE_CPP	= $(shell realpath $(shell find $(IGNORE_SRC_PATH) \
 				-type f -name "*.cpp" ) 2>/dev/null)
 endif
 
-SRC_C 	= $(filter-out $(IGNORE_C), $(ALL_SRC_C))
+SRC_C 	+= $(filter-out $(IGNORE_C), $(ALL_SRC_C))
 SRC_CPP = $(filter-out $(IGNORE_CPP), $(ALL_SRC_CPP))
 
 # discover the ASM source files in project directory
diff --git a/shell/shell/shell.c b/shell/shell/shell.c
index 2f1459c..92c5d18 100644
--- a/shell/shell/shell.c
+++ b/shell/shell/shell.c
@@ -1,482 +1,488 @@
-/**
- * Copyright 2021 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- **/
-
-#include "shell.h"
-
-#include <stdbool.h>
-
-#include "shell_config.h"
-#include "string.h"
-
-int (*__read_char__)(void);
-void (*__write_char__)(char c);
-
-extern unsigned long int __CMD_TABLE_START__;
-extern unsigned long int __AUTO_TABLE_START__;
-
-static const cmd_t *volatile table = (cmd_t *)&__CMD_TABLE_START__;
-static const cmd_t *volatile auto_load = (cmd_t *)&__AUTO_TABLE_START__;
-static volatile int __cmd_exec_status;
-
-/*
- * To reduce the shell size the history feature
- * is made optional. Skip history feature if
- * SHELL_NO_HISTORY is defined.
- */
-#ifndef SHELL_NO_HISTORY
-static volatile int total_num_commands = 0;
-static volatile int curr_command_ptr = 0;
-static char cmd_history[NUM_HISTORY_ENTRIES][LINE_BUFF_SIZE];
-#endif
-
-static volatile bool __echo = ECHO_INIT_VALUE;  // Should be set in the Makefile
-
-void set_read_char(int (*func)(void)) { __read_char__ = func; }
-
-void set_write_char(void (*func)(char)) { __write_char__ = func; }
-
-__attribute__((weak)) void setup(void) {
-  // to be provided by the user
-}
-
-__attribute__((weak)) void loop(void) {
-  // to be provided by the user
-}
-
-// This method is a place holder to prepend prompt
-__attribute__((weak)) void prepend_prompt() {
-  ;  // nothing by default
-}
-
-// Check if prompt is active, by default true.
-// Platforms can decide a logic for this.
-__attribute__((weak)) int active_prompt() { return TRUE; }
-
-static void delete(void) {
-  __write_char__(BACK_SPACE);
-  __write_char__(SPACE);
-  __write_char__(BACK_SPACE);
-}
-
-static void clear_prompt(int char_count) {
-  while (char_count) {
-    delete ();
-    char_count--;
-  }
-}
-
-/*
- * To reduce the shell size the history feature
- * is made optional. Skip history feature if
- * SHELL_NO_HISTORY is defined.
- */
-#ifndef SHELL_NO_HISTORY
-static void handle_up_arrow(char *cmd_buff, int *char_count) {
-  if (curr_command_ptr < total_num_commands - NUM_HISTORY_ENTRIES ||
-      curr_command_ptr == 0) {
-    printf("%s", cmd_buff);
-    return;
-  }
-
-  memset(cmd_buff, 0, LINE_BUFF_SIZE);
-
-  curr_command_ptr--;
-  int index = (curr_command_ptr % NUM_HISTORY_ENTRIES);
-  memcpy(cmd_buff, &cmd_history[index], LINE_BUFF_SIZE);
-  *char_count = strlen(cmd_buff);
-
-  printf("%s", cmd_buff);
-}
-
-static void handle_down_arrow(char *cmd_buff, int *char_count) {
-  memset(cmd_buff, 0, LINE_BUFF_SIZE);
-  *char_count = 0;
-  if (curr_command_ptr == total_num_commands) return;
-
-  curr_command_ptr++;
-  int index = (curr_command_ptr % NUM_HISTORY_ENTRIES);
-  memcpy(cmd_buff, &cmd_history[index], LINE_BUFF_SIZE);
-  *char_count = strlen(cmd_buff);
-
-  printf("%s", cmd_buff);
-}
-
-static void add_command_to_history(const char *cmd_str) {
-
-  //add only if command is not empty
-  if (cmd_str == NULL || strcmp(cmd_str, "") == 0) {
-    return;
-  }
-  int index = total_num_commands % NUM_HISTORY_ENTRIES;
-  memcpy(&cmd_history[index], cmd_str, LINE_BUFF_SIZE);
-  total_num_commands++;
-  curr_command_ptr = total_num_commands;
-}
-
-static int show_history(int argc, char **argv) {
-  uint32_t end_index = total_num_commands-1;
-  uint32_t beg_index = 0;
-  if (total_num_commands > NUM_HISTORY_ENTRIES) {
-    beg_index = total_num_commands - NUM_HISTORY_ENTRIES;
-  }
-  for (uint32_t index = beg_index; index <= end_index; ++index) {
-    printf("%s\n", cmd_history[index % NUM_HISTORY_ENTRIES]);
-  }
-
-  return 0;
-}
-
-ADD_CMD(history, "Show command history", show_history);
-
-#endif  // SHELL_NO_HISTORY
-
-
-#ifndef SHELL_NO_TAB_COMPLETE
-
-static int prefix_match(char *sub, int len, const char *str) {
-  if (sub == NULL || str == NULL || len <= 0 || len > strlen(str)) {
-    return FALSE;
-  }
-
-  for (int i = 0; i<len; ++i) {
-    if (sub[i] != str[i]) {
-      return FALSE;
-    }
-  }
-
-  return TRUE;
-}
-static void handle_tab(char *cmd_buff, int *char_count) {
-  if (cmd_buff == NULL || char_count <= 0) {
-    return;
-  }
-
-  int i = 0;
-  int match_count = 0;
-  int last_match = -1;
-  while (table[i].command_name != NULL) { //loop over all commands
-
-    //if prefix matches, print that as one of the options
-    if (prefix_match(cmd_buff, *char_count, table[i].command_name)) {
-      match_count++;
-      last_match = i;
-      printf("\n%s", table[i].command_name);
-    }
-
-    i++;
-  }
-
-  // if only one match, then that's the command to be executed
-  if (match_count == 1) {
-    memcpy(cmd_buff, table[last_match].command_name, LINE_BUFF_SIZE);
-    *char_count = strlen(cmd_buff);
-  }
-
-  // print current line with old/updated command
-  if (match_count) {
-    printf("\n");
-    prepend_prompt();
-    printf(PROMPT);
-    printf("%s", cmd_buff);
-  }
-}
-
-#endif  // SHELL_NO_TAB_COMPLETE
-
-static int parse_line(char **argv, char *line_buff, int argument_size) {
-  int argc = 0;
-  int pos = 0;
-  int length = strlen(line_buff);
-
-  while (pos <= length) {
-    if (line_buff[pos] != '\t' && line_buff[pos] != SPACE &&
-        line_buff[pos] != END_OF_LINE)
-      argv[argc++] = &line_buff[pos];
-
-    for (; line_buff[pos] != '\t' && line_buff[pos] != SPACE &&
-           line_buff[pos] != END_OF_LINE;
-         pos++)
-      ;
-
-    if (line_buff[pos] == '\t' || line_buff[pos] == SPACE)
-      line_buff[pos] = END_OF_LINE;
-
-    pos++;
-  }
-
-  return argc;
-}
-
-static void execute(int argc, char **argv) {
-  int match_found = FALSE;
-
-  for (int i = 0; table[i].command_name != NULL; i++) {
-    if (strcmp(argv[0], table[i].command_name) == 0) {
-      __cmd_exec_status = table[i].command(argc, &argv[0]);
-      match_found = TRUE;
-      break;
-    }
-  }
-
-  if (match_found == FALSE) {
-    printf("\"%s\": command not found. Use \"help\" to list all command.\n",
-           argv[0]);
-    __cmd_exec_status = -1;
-  }
-}
-
-static void shell(void) {
-  int s, argc;
-  int count = 0;
-  int special_key = 0;
-  char c;
-
-  char line_buff[LINE_BUFF_SIZE];
-  char *argv[MAX_ARG_COUNT];
-
-  for (int i = 0; i < LINE_BUFF_SIZE; i++) line_buff[i] = 0;
-
-  for (int i = 0; i < MAX_ARG_COUNT; i++) argv[i] = NULL;
-
-  prepend_prompt();
-  printf(PROMPT);
-
-  while (TRUE) {
-    if (!active_prompt()) {
-      continue;
-    }
-
-    s = __read_char__();
-    if (s != -1) {
-      c = (char)s;
-
-      if (c == CARRIAGE_RETURN || c == NEW_LINE) {
-        line_buff[count] = END_OF_LINE;
-        __write_char__(NEW_LINE);
-        break;
-      }
-
-      if (c == DELETE || c == BACK_SPACE) {
-        if (!__echo) {
-          delete ();
-          delete ();
-        }
-
-        // guard against the count going negative!
-        if (count == 0) continue;
-
-        count--;
-
-        line_buff[count] = END_OF_LINE;
-        delete ();
-      } else if (c == ESCAPE) {
-        special_key = 1;
-        continue;
-      } else if (c == SQUARE_BRACKET_OPEN && special_key == 1) {
-        special_key = 2;
-        continue;
-      } else if ((c == 'C' || c == 'D') && special_key != 0) {
-        /* Ignore left/right arrow keys */
-        special_key = 0;
-        continue;
-      } else if ((c == 'A' || c == 'B') && special_key == 2) {
-        if (!__echo) {
-          clear_prompt(count + 4);
-        } else {
-          clear_prompt(count);
-        }
-/*
- * To reduce the shell size the history feature
- * is made optional. Skip history feature if
- * SHELL_NO_HISTORY is defined.
- */
-#ifndef SHELL_NO_HISTORY
-        if (c == 'A') {
-          handle_up_arrow(line_buff, &count);
-        } else {
-          handle_down_arrow(line_buff, &count);
-        }
-#endif  // SHELL_NO_HISTORY
-        special_key = 0;
-        continue;
-      }
-#ifndef SHELL_NO_TAB_COMPLETE
-      else if (c == TAB) {
-        handle_tab(line_buff, &count);
-        continue;
-      }
-#endif //SHELL_NO_TAB_COMPLETE
-      else {
-        line_buff[count] = c;
-        count++;
-      }
-      if (__echo && c != DELETE && c != BACK_SPACE) {
-        __write_char__(c);
-      }
-    } else {
-      loop();
-    }
-  }
-
-/*
- * To reduce the shell size the history feature
- * is made optional. Skip history feature if
- * SHELL_NO_HISTORY is defined.
- */
-#ifndef SHELL_NO_HISTORY
-  add_command_to_history(line_buff);
-#endif
-
-  // parse the line_buff
-  argc = parse_line(argv, line_buff, MAX_ARG_COUNT);
-
-  // execute the parsed commands
-  if (argc > 0) execute(argc, argv);
-}
-
-static void exec_auto_cmds(void) {
-  for (int i = 0; auto_load[i].command_name != NULL; i++) {
-    auto_load[i].command(0, NULL);
-  }
-}
-
-static int build_info(int argc, char **argv) {
-  printf("Build: [" SHELL_VERSION ":" USER_REPO_VERSION "] - [" BUILD_USER
-         "@" BUILD_HOST "] - " __DATE__ " - " __TIME__ "\n");
-  return 0;
-}
-
-
-void __attribute__((optimize("O0"), weak)) initial_setup(void) {
-  /**
-   * Copy the data section from ROM to RAM and
-   * zero init the bss section if we are using
-   * Two segment memory.
-   *
-   * In case everything is in the RAM, skip copying the .data section
-   * and zero the .bss section. This helps keep the user/custom
-   * linker script and makefiles free from special variables to be declared.
-   * Less burden on the user.
-   */
-  extern char _etext, _data, _edata, _bss, _ebss;
-  char *src = &_etext, *dst = &_data;
-
-  /**
-   * Copy over the data section from ROM to RAM.
-   * In case of RAM based target, we skip this since
-   * src and dst would point to same location in RAM
-   */
-  if (dst != src)
-    while (dst < &_edata) *(dst++) = *(src++);
-
-  /* Clear .bss*/
-  for (dst = &_bss; dst < &_ebss; dst++) *dst = 0;
-
-  /**
-   * platform_init() is expected to be defined by the user.
-   * Expectation is that the user would do any needed hardware initialization
-   * And register two functions to read a byte and write a byte using
-   * - set_read_char(<way to read a byte>);
-   * - set_write_char(<way to write a byte>);
-   *
-   * typical implementation may look like:
-   * void platform_init(void) {
-   *   uart_init();
-   *   set_read_char(uart_getchar);
-   *   set_write_char(uart_putchar);
-   * }
-   */
-  platform_init();
-}
-
-/**
- * @brief spwans the prompt
- *
- */
-void prompt() {
-  initial_setup();
-  exec_auto_cmds();
-  setup();
-
-  while (TRUE) {
-    shell();
-  }
-}
-
-int exec(char *cmd_str) {
-  int argc;
-
-  // TODO: this takes too much stack space. Optimize!
-  char *argv[MAX_ARG_COUNT];
-
-  // parse the line_buff
-  argc = parse_line(argv, cmd_str, MAX_ARG_COUNT);
-
-  // execute the parsed commands
-  if (argc > 0) execute(argc, argv);
-
-  return __cmd_exec_status;
-}
-
-cmd get_function_addr(char *cmd_str) {
-  for (int i = 0; table[i].command_name != NULL; i++) {
-    if (strcmp(cmd_str, table[i].command_name) == 0) {
-      return table[i].command;
-    }
-  }
-  return NULL;
-}
-
-int help(int argc, char **argv) {
-  int i = 0;
-  /* Default to Verbose */
-  bool verbose = true;
-
-  if (argc > 1 && (strcmp(argv[1], "-l")==0)) {
-    verbose = false;
-  } else {
-    printf("use: help -l for list only.\n\n");
-  }
-
-  while (table[i].command_name != NULL) {
-    printf(table[i].command_name);
-
-    if (verbose) {
-      printf("\n\t");
-      printf(table[i].command_help);
-    }
-
-    printf("\n");
-    i++;
-  }
-
-  return 0;
-}
-
-int cmd_exec_status(int argc, char **argv) {
-  printf("%d\n", __cmd_exec_status);
-  return 0;
-}
-
-// DO NOT REMOVE THESE
-AUTO_CMD(version, "Prints details of the build", build_info);
-ADD_CMD(help, "Prints all available commands", help);
-ADD_CMD(status, "Returns exit status of last executed command",
-        cmd_exec_status);
-
-// Mandatory!
-__attribute__((section(".cmd_end"))) static volatile cmd_t cmd_end_ = {
-    NULL, NULL, NULL};
+/**
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+#include "shell.h"
+
+#include <stdbool.h>
+
+#include "shell_config.h"
+#include "string.h"
+
+int (*__read_char__)(void);
+void (*__write_char__)(char c);
+
+extern unsigned long int __CMD_TABLE_START__;
+extern unsigned long int __AUTO_TABLE_START__;
+
+static const cmd_t *volatile table = (cmd_t *)&__CMD_TABLE_START__;
+static const cmd_t *volatile auto_load = (cmd_t *)&__AUTO_TABLE_START__;
+static volatile int __cmd_exec_status;
+
+/*
+ * To reduce the shell size the history feature
+ * is made optional. Skip history feature if
+ * SHELL_NO_HISTORY is defined.
+ */
+#ifndef SHELL_NO_HISTORY
+static volatile int total_num_commands = 0;
+static volatile int curr_command_ptr = 0;
+static char cmd_history[NUM_HISTORY_ENTRIES][LINE_BUFF_SIZE];
+#endif
+
+static volatile bool __echo = ECHO_INIT_VALUE;  // Should be set in the Makefile
+
+void set_read_char(int (*func)(void)) { __read_char__ = func; }
+
+void set_write_char(void (*func)(char)) { __write_char__ = func; }
+
+__attribute__((weak)) void setup(void) {
+  // to be provided by the user
+}
+
+__attribute__((weak)) void loop(void) {
+  // to be provided by the user
+}
+
+// This method is a place holder to prepend prompt
+__attribute__((weak)) void prepend_prompt() {
+  ;  // nothing by default
+}
+
+// Check if prompt is active, by default true.
+// Platforms can decide a logic for this.
+__attribute__((weak)) int active_prompt() { return TRUE; }
+
+static void delete(void) {
+  __write_char__(BACK_SPACE);
+  __write_char__(SPACE);
+  __write_char__(BACK_SPACE);
+}
+
+static void clear_prompt(int char_count) {
+  while (char_count) {
+    delete ();
+    char_count--;
+  }
+}
+
+/*
+ * To reduce the shell size the history feature
+ * is made optional. Skip history feature if
+ * SHELL_NO_HISTORY is defined.
+ */
+#ifndef SHELL_NO_HISTORY
+static void handle_up_arrow(char *cmd_buff, int *char_count) {
+  if (curr_command_ptr < total_num_commands - NUM_HISTORY_ENTRIES ||
+      curr_command_ptr == 0) {
+    printf("%s", cmd_buff);
+    return;
+  }
+
+  memset(cmd_buff, 0, LINE_BUFF_SIZE);
+
+  curr_command_ptr--;
+  int index = (curr_command_ptr % NUM_HISTORY_ENTRIES);
+  memcpy(cmd_buff, &cmd_history[index], LINE_BUFF_SIZE);
+  *char_count = strlen(cmd_buff);
+
+  printf("%s", cmd_buff);
+}
+
+static void handle_down_arrow(char *cmd_buff, int *char_count) {
+  memset(cmd_buff, 0, LINE_BUFF_SIZE);
+  *char_count = 0;
+  if (curr_command_ptr == total_num_commands) return;
+
+  curr_command_ptr++;
+  int index = (curr_command_ptr % NUM_HISTORY_ENTRIES);
+  memcpy(cmd_buff, &cmd_history[index], LINE_BUFF_SIZE);
+  *char_count = strlen(cmd_buff);
+
+  printf("%s", cmd_buff);
+}
+
+static void add_command_to_history(const char *cmd_str) {
+
+  //add only if command is not empty
+  if (cmd_str == NULL || strcmp(cmd_str, "") == 0) {
+    return;
+  }
+  int index = total_num_commands % NUM_HISTORY_ENTRIES;
+  memcpy(&cmd_history[index], cmd_str, LINE_BUFF_SIZE);
+  total_num_commands++;
+  curr_command_ptr = total_num_commands;
+}
+
+static int show_history(int argc, char **argv) {
+  uint32_t end_index = total_num_commands-1;
+  uint32_t beg_index = 0;
+  if (total_num_commands > NUM_HISTORY_ENTRIES) {
+    beg_index = total_num_commands - NUM_HISTORY_ENTRIES;
+  }
+  for (uint32_t index = beg_index; index <= end_index; ++index) {
+    printf("%s\n", cmd_history[index % NUM_HISTORY_ENTRIES]);
+  }
+
+  return 0;
+}
+
+ADD_CMD(history, "Show command history", show_history);
+
+#endif  // SHELL_NO_HISTORY
+
+
+#ifndef SHELL_NO_TAB_COMPLETE
+
+static int prefix_match(char *sub, int len, const char *str) {
+  if (sub == NULL || str == NULL || len <= 0 || len > strlen(str)) {
+    return FALSE;
+  }
+
+  for (int i = 0; i<len; ++i) {
+    if (sub[i] != str[i]) {
+      return FALSE;
+    }
+  }
+
+  return TRUE;
+}
+static void handle_tab(char *cmd_buff, int *char_count) {
+  if (cmd_buff == NULL || char_count <= 0) {
+    return;
+  }
+
+  int i = 0;
+  int match_count = 0;
+  int last_match = -1;
+  while (table[i].command_name != NULL) { //loop over all commands
+
+    //if prefix matches, print that as one of the options
+    if (prefix_match(cmd_buff, *char_count, table[i].command_name)) {
+      match_count++;
+      last_match = i;
+      printf("\n%s", table[i].command_name);
+    }
+
+    i++;
+  }
+
+  // if only one match, then that's the command to be executed
+  if (match_count == 1) {
+    memcpy(cmd_buff, table[last_match].command_name, LINE_BUFF_SIZE);
+    *char_count = strlen(cmd_buff);
+  }
+
+  // print current line with old/updated command
+  if (match_count) {
+    printf("\n");
+    prepend_prompt();
+    printf(PROMPT);
+    printf("%s", cmd_buff);
+  }
+}
+
+#endif  // SHELL_NO_TAB_COMPLETE
+
+static int parse_line(char **argv, char *line_buff, int argument_size) {
+  int argc = 0;
+  int pos = 0;
+  int length = strlen(line_buff);
+
+  while (pos <= length) {
+    if (line_buff[pos] != '\t' && line_buff[pos] != SPACE &&
+        line_buff[pos] != END_OF_LINE)
+      argv[argc++] = &line_buff[pos];
+
+    for (; line_buff[pos] != '\t' && line_buff[pos] != SPACE &&
+           line_buff[pos] != END_OF_LINE;
+         pos++)
+      ;
+
+    if (line_buff[pos] == '\t' || line_buff[pos] == SPACE)
+      line_buff[pos] = END_OF_LINE;
+
+    pos++;
+  }
+
+  return argc;
+}
+
+static void execute(int argc, char **argv) {
+  int match_found = FALSE;
+
+  for (int i = 0; table[i].command_name != NULL; i++) {
+    if (strcmp(argv[0], table[i].command_name) == 0) {
+      __cmd_exec_status = table[i].command(argc, &argv[0]);
+      match_found = TRUE;
+      break;
+    }
+  }
+
+  if (match_found == FALSE) {
+    printf("\"%s\": command not found. Use \"help\" to list all command.\n",
+           argv[0]);
+    __cmd_exec_status = -1;
+  }
+}
+
+static void shell(void) {
+  int s, argc;
+  int count = 0;
+  int special_key = 0;
+  char c;
+
+  char line_buff[LINE_BUFF_SIZE];
+  char *argv[MAX_ARG_COUNT];
+
+  for (int i = 0; i < LINE_BUFF_SIZE; i++) line_buff[i] = 0;
+
+  for (int i = 0; i < MAX_ARG_COUNT; i++) argv[i] = NULL;
+
+  prepend_prompt();
+  printf(PROMPT);
+
+  while (TRUE) {
+    if (!active_prompt()) {
+      continue;
+    }
+
+    s = __read_char__();
+    if (s != -1) {
+      c = (char)s;
+
+      if (c == CARRIAGE_RETURN || c == NEW_LINE) {
+        line_buff[count] = END_OF_LINE;
+        __write_char__(NEW_LINE);
+        break;
+      }
+
+      if (c == DELETE || c == BACK_SPACE) {
+        if (!__echo) {
+          delete ();
+          delete ();
+        }
+
+        // guard against the count going negative!
+        if (count == 0) continue;
+
+        count--;
+
+        line_buff[count] = END_OF_LINE;
+        delete ();
+      } else if (c == ESCAPE) {
+        special_key = 1;
+        continue;
+      } else if (c == SQUARE_BRACKET_OPEN && special_key == 1) {
+        special_key = 2;
+        continue;
+      } else if ((c == 'C' || c == 'D') && special_key != 0) {
+        /* Ignore left/right arrow keys */
+        special_key = 0;
+        continue;
+      } else if ((c == 'A' || c == 'B') && special_key == 2) {
+        if (!__echo) {
+          clear_prompt(count + 4);
+        } else {
+          clear_prompt(count);
+        }
+/*
+ * To reduce the shell size the history feature
+ * is made optional. Skip history feature if
+ * SHELL_NO_HISTORY is defined.
+ */
+#ifndef SHELL_NO_HISTORY
+        if (c == 'A') {
+          handle_up_arrow(line_buff, &count);
+        } else {
+          handle_down_arrow(line_buff, &count);
+        }
+#endif  // SHELL_NO_HISTORY
+        special_key = 0;
+        continue;
+      }
+#ifndef SHELL_NO_TAB_COMPLETE
+      else if (c == TAB) {
+        handle_tab(line_buff, &count);
+        continue;
+      }
+#endif //SHELL_NO_TAB_COMPLETE
+      else {
+        line_buff[count] = c;
+        count++;
+      }
+      if (__echo && c != DELETE && c != BACK_SPACE) {
+        __write_char__(c);
+      }
+    } else {
+      loop();
+    }
+  }
+
+/*
+ * To reduce the shell size the history feature
+ * is made optional. Skip history feature if
+ * SHELL_NO_HISTORY is defined.
+ */
+#ifndef SHELL_NO_HISTORY
+  add_command_to_history(line_buff);
+#endif
+
+  // parse the line_buff
+  argc = parse_line(argv, line_buff, MAX_ARG_COUNT);
+
+  // execute the parsed commands
+  if (argc > 0) execute(argc, argv);
+}
+
+static void exec_auto_cmds(void) {
+  for (int i = 0; auto_load[i].command_name != NULL; i++) {
+    auto_load[i].command(0, NULL);
+  }
+}
+
+static int build_info(int argc, char **argv) {
+  printf("Build: [" SHELL_VERSION ":" USER_REPO_VERSION "] - [" BUILD_USER
+         "@" BUILD_HOST "] - " __DATE__ " - " __TIME__ "\n");
+  return 0;
+}
+
+
+void __attribute__((optimize("O0"), weak)) initial_setup(void) {
+  /**
+   * Copy the data section from ROM to RAM and
+   * zero init the bss section if we are using
+   * Two segment memory.
+   *
+   * In case everything is in the RAM, skip copying the .data section
+   * and zero the .bss section. This helps keep the user/custom
+   * linker script and makefiles free from special variables to be declared.
+   * Less burden on the user.
+   */
+  extern char _etext, _data, _edata, _bss, _ebss;
+  char *src = &_etext, *dst = &_data;
+
+  /**
+   * Copy over the data section from ROM to RAM.
+   * In case of RAM based target, we skip this since
+   * src and dst would point to same location in RAM
+   */
+  if (dst != src)
+    while (dst < &_edata) *(dst++) = *(src++);
+
+  /* Clear .bss*/
+  for (dst = &_bss; dst < &_ebss; dst++) *dst = 0;
+
+  /**
+   * platform_init() is expected to be defined by the user.
+   * Expectation is that the user would do any needed hardware initialization
+   * And register two functions to read a byte and write a byte using
+   * - set_read_char(<way to read a byte>);
+   * - set_write_char(<way to write a byte>);
+   *
+   * typical implementation may look like:
+   * void platform_init(void) {
+   *   uart_init();
+   *   set_read_char(uart_getchar);
+   *   set_write_char(uart_putchar);
+   * }
+   */
+  platform_init();
+}
+
+/**
+ * @brief spwans the prompt
+ *
+ */
+void prompt() {
+  initial_setup();
+  exec_auto_cmds();
+  setup();
+
+  // while (TRUE) {
+  //   shell();
+  // }
+}
+
+void shell1(){
+  while(1){
+    shell();
+  }
+}
+
+int exec(char *cmd_str) {
+  int argc;
+
+  // TODO: this takes too much stack space. Optimize!
+  char *argv[MAX_ARG_COUNT];
+
+  // parse the line_buff
+  argc = parse_line(argv, cmd_str, MAX_ARG_COUNT);
+
+  // execute the parsed commands
+  if (argc > 0) execute(argc, argv);
+
+  return __cmd_exec_status;
+}
+
+cmd get_function_addr(char *cmd_str) {
+  for (int i = 0; table[i].command_name != NULL; i++) {
+    if (strcmp(cmd_str, table[i].command_name) == 0) {
+      return table[i].command;
+    }
+  }
+  return NULL;
+}
+
+int help(int argc, char **argv) {
+  int i = 0;
+  /* Default to Verbose */
+  bool verbose = true;
+
+  if (argc > 1 && (strcmp(argv[1], "-l")==0)) {
+    verbose = false;
+  } else {
+    printf("use: help -l for list only.\n\n");
+  }
+
+  while (table[i].command_name != NULL) {
+    printf(table[i].command_name);
+
+    if (verbose) {
+      printf("\n\t");
+      printf(table[i].command_help);
+    }
+
+    printf("\n");
+    i++;
+  }
+
+  return 0;
+}
+
+int cmd_exec_status(int argc, char **argv) {
+  printf("%d\n", __cmd_exec_status);
+  return 0;
+}
+
+// DO NOT REMOVE THESE
+AUTO_CMD(version, "Prints details of the build", build_info);
+ADD_CMD(help, "Prints all available commands", help);
+ADD_CMD(status, "Returns exit status of last executed command",
+        cmd_exec_status);
+
+// Mandatory!
+__attribute__((section(".cmd_end"))) static volatile cmd_t cmd_end_ = {
+    NULL, NULL, NULL};
\ No newline at end of file
diff --git a/shell/startup/cortex-m.S b/shell/startup/cortex-m.S
index 6e95303..212fa93 100644
--- a/shell/startup/cortex-m.S
+++ b/shell/startup/cortex-m.S
@@ -19,5 +19,5 @@
 .globl reset_handler
 .type reset_handler, %function
 reset_handler:
-    bl prompt
+    bl main_blinky1
     bl .