diff --git a/.gitignore b/.gitignore
index 016358f..392f5b2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,4 @@ CMakeFiles
 cmake_install.cmake
 CMakeCache.txt
 demo/x86-gcc/Makefile
-demo/x86-gcc/LetterShell
\ No newline at end of file
+demo/x86-gcc/LetterShell
diff --git a/README.md b/README.md
index 2792037..d7550c4 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 ![version](https://img.shields.io/badge/version-3.1.0-brightgreen.svg)
 ![standard](https://img.shields.io/badge/standard-c99-brightgreen.svg)
-![build](https://img.shields.io/badge/build-2021.05.09-brightgreen.svg)
+![build](https://img.shields.io/badge/build-2021.05.24-brightgreen.svg)
 ![license](https://img.shields.io/badge/license-MIT-brightgreen.svg)
 
 一个功能强大的嵌入式shell
@@ -108,7 +108,7 @@
      *
      * @return unsigned short 实际写入的字符数量
      */
-    typedef unsigned short (*shellWrite)(const char *data, unsigned short len);
+    typedef unsigned short (*shellWrite)(char *data, unsigned short len);
     ```
 
 3. 申请一片缓冲区
diff --git a/demo/stm32-freertos/shell_cfg.h b/demo/stm32-freertos/shell_cfg.h
index ae01e0d..7961fcf 100644
--- a/demo/stm32-freertos/shell_cfg.h
+++ b/demo/stm32-freertos/shell_cfg.h
@@ -13,6 +13,8 @@
 #define __SHELL_CFG_H__
 
 #include "stm32f4xx_hal.h"
+#include "FreeRTOS.h"
+#include "portable.h"
 
 
 /**
@@ -33,12 +35,13 @@
  * @brief 是否使用shell伴生对象
  *        一些扩展的组件(文件系统支持，日志工具等)需要使用伴生对象
  */
-#define     SHELL_USING_COMPANION       0
+#define     SHELL_USING_COMPANION       1
+
 
 /**
  * @brief 支持shell尾行模式
  */
-#define     SHELL_SUPPORT_END_LINE      0
+#define     SHELL_SUPPORT_END_LINE      1
 
 /**
  * @brief 是否在输出命令列表中列出用户
@@ -64,7 +67,7 @@
  * @brief 使用LF作为命令行回车触发
  *        可以和SHELL_ENTER_CR同时开启
  */
-#define     SHELL_ENTER_LF              0
+#define     SHELL_ENTER_LF              1
 
 /**
  * @brief 使用CR作为命令行回车触发
@@ -113,6 +116,13 @@
  */
 #define     SHELL_PRINT_BUFFER          128
 
+/**
+ * @brief shell格式化输入的缓冲大小
+ *        为0时不使用shell格式化输入
+ * @note shell格式化输入会阻塞shellTask, 仅适用于在有操作系统的情况下使用
+ */
+#define     SHELL_SCAN_BUFFER          128
+
 /**
  * @brief 获取系统时间(ms)
  *        定义此宏为获取系统Tick，如`HAL_GetTick()`
@@ -120,17 +130,23 @@
  */
 #define     SHELL_GET_TICK()            HAL_GetTick()
 
+/**
+ * @brief 使用锁
+ * @note 使用shell锁时，需要对加锁和解锁进行实现
+ */
+#define     SHELL_USING_LOCK            1
+
 /**
  * @brief shell内存分配
  *        shell本身不需要此接口，若使用shell伴生对象，需要进行定义
  */
-#define     SHELL_MALLOC(size)          0
+#define     SHELL_MALLOC(size)          pvPortMalloc(size)
 
 /**
  * @brief shell内存释放
  *        shell本身不需要此接口，若使用shell伴生对象，需要进行定义
  */
-#define     SHELL_FREE(obj)             0
+#define     SHELL_FREE(obj)             vPortFree(obj)
 
 /**
  * @brief 是否显示shell信息
@@ -162,3 +178,4 @@
 #define     SHELL_LOCK_TIMEOUT          0 * 60 * 1000
 
 #endif
+
diff --git a/demo/stm32-freertos/shell_port.c b/demo/stm32-freertos/shell_port.c
index 916469c..7369c97 100644
--- a/demo/stm32-freertos/shell_port.c
+++ b/demo/stm32-freertos/shell_port.c
@@ -9,23 +9,33 @@
  * 
  */
 
+#include "FreeRTOS.h"
+#include "task.h"
 #include "shell.h"
 #include "serial.h"
 #include "stm32f4xx_hal.h"
 #include "usart.h"
+#include "cevent.h"
+#include "log.h"
 
 
 Shell shell;
 char shellBuffer[512];
 
+static SemaphoreHandle_t shellMutex;
+
 /**
  * @brief 用户shell写
  * 
  * @param data 数据
+ * @param len 数据长度
+ * 
+ * @return short 实际写入的数据长度
  */
-void userShellWrite(char data)
+short userShellWrite(char *data, unsigned short len)
 {
-    serialTransmit(&debugSerial, (uint8_t *)&data, 1, 0xFF);
+    serialTransmit(&debugSerial, (uint8_t *)data, len, 0x1FF);
+    return len;
 }
 
 
@@ -33,21 +43,40 @@ void userShellWrite(char data)
  * @brief 用户shell读
  * 
  * @param data 数据
- * @return char 状态
+ * @param len 数据长度
+ * 
+ * @return short 实际读取到
  */
-signed char userShellRead(char *data)
+short userShellRead(char *data, unsigned short len)
 {
-    if (serialReceive(&debugSerial, (uint8_t *)data, 1, 0) == 1)
-    {
-        return 0;
-    }
-    else
-    {
-        return -1;
-    }
-    
+    return serialReceive(&debugSerial, (uint8_t *)data, len, 0);
 }
 
+/**
+ * @brief 用户shell上锁
+ * 
+ * @param shell shell
+ * 
+ * @return int 0
+ */
+int userShellLock(Shell *shell)
+{
+    xSemaphoreTakeRecursive(shellMutex, portMAX_DELAY);
+    return 0;
+}
+
+/**
+ * @brief 用户shell解锁
+ * 
+ * @param shell shell
+ * 
+ * @return int 0
+ */
+int userShellUnlock(Shell *shell)
+{
+    xSemaphoreGiveRecursive(shellMutex);
+    return 0;
+}
 
 /**
  * @brief 用户shell初始化
@@ -55,8 +84,17 @@ signed char userShellRead(char *data)
  */
 void userShellInit(void)
 {
+    shellMutex = xSemaphoreCreateMutex();
+
     shell.write = userShellWrite;
     shell.read = userShellRead;
+    shell.lock = userShellLock;
+    shell.unlock = userShellUnlock;
     shellInit(&shell, shellBuffer, 512);
+    if (xTaskCreate(shellTask, "shell", 256, &shell, 5, NULL) != pdPASS)
+    {
+        logError("shell task creat failed");
+    }
 }
+CEVENT_EXPORT(EVENT_INIT_STAGE2, userShellInit);
 
diff --git a/extensions/cpp_support/shell_cpp.h b/extensions/cpp_support/shell_cpp.h
index 2ae951d..946d83f 100644
--- a/extensions/cpp_support/shell_cpp.h
+++ b/extensions/cpp_support/shell_cpp.h
@@ -139,7 +139,7 @@ typedef struct shell_command_cpp_key
             const char shellDesc##_value[] = #_desc; \
             extern "C" SHELL_USED const ShellCommandCppKey \
             shellKey##_value SHELL_SECTION("shellCommand") =  \
-            { \ 
+            { \
                 _attr|SHELL_CMD_TYPE(SHELL_TYPE_KEY), \
                 _value, \
                 (void (*)(Shell *))_func, \
@@ -152,3 +152,4 @@ typedef struct shell_command_cpp_key
 
 #endif /**< __SHELL_CPP_H__ */
 
+
diff --git a/src/shell.c b/src/shell.c
index 803616d..a5daebc 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -258,7 +258,7 @@ Shell* shellGetCurrent(void)
  * @param shell shell对象
  * @param data 字符数据
  */
-static void shellWriteByte(Shell *shell, const char data)
+static void shellWriteByte(Shell *shell, char data)
 {
     shell->write(&data, 1);
 }
@@ -275,13 +275,13 @@ static void shellWriteByte(Shell *shell, const char data)
 unsigned short shellWriteString(Shell *shell, const char *string)
 {
     unsigned short count = 0;
-    char *p = string;
+    const char *p = string;
     SHELL_ASSERT(shell->write, return 0);
     while(*p++)
     {
         count ++;
     }
-    return shell->write(string, count);
+    return shell->write((char *)string, count);
 }
 
 
@@ -296,7 +296,7 @@ unsigned short shellWriteString(Shell *shell, const char *string)
 static unsigned short shellWriteCommandDesc(Shell *shell, const char *string)
 {
     unsigned short count = 0;
-    char *p = string;
+    const char *p = string;
     SHELL_ASSERT(shell->write, return 0);
     while (*p && *p != '\r' && *p != '\n')
     {
@@ -306,12 +306,12 @@ static unsigned short shellWriteCommandDesc(Shell *shell, const char *string)
     
     if (count > 36)
     {
-        shell->write(string, 36);
+        shell->write((char *)string, 36);
         shell->write("...", 3);
     }
     else
     {
-        shell->write(string, count);
+        shell->write((char *)string, count);
     }
     return count > 36 ? 36 : 39;
 }
@@ -389,7 +389,7 @@ void shellScan(Shell *shell, char *fmt, ...)
         do {
             if (shell->read(&buffer[index], 1) == 1)
             {
-                shell->write(buffer[index], 1);
+                shell->write(&buffer[index], 1);
                 index++;
             }
         } while (buffer[index -1] != '\r' && buffer[index -1] != '\n' && index < SHELL_SCAN_BUFFER);
@@ -1757,7 +1757,7 @@ void shellWriteEndLine(Shell *shell, char *buffer, int len)
             shellWriteString(shell, shell->parser.buffer);
             for (short i = 0; i < shell->parser.length - shell->parser.cursor; i++)
             {
-                shell->write('\b', 1);
+                shellWriteByte(shell, '\b');
             }
         }
     }
@@ -1927,3 +1927,4 @@ SHELL_EXPORT_CMD(
 SHELL_CMD_PERMISSION(0)|SHELL_CMD_TYPE(SHELL_TYPE_CMD_MAIN)|SHELL_CMD_DISABLE_RETURN,
 exec, shellExecute, execute function undefined);
 #endif
+
diff --git a/src/shell.h b/src/shell.h
index fad42a9..5f2aa56 100644
--- a/src/shell.h
+++ b/src/shell.h
@@ -360,7 +360,7 @@ typedef struct shell_def
         unsigned char tabFlag : 1;                              /**< tab标志 */
     } status;
     signed short (*read)(char *, unsigned short);               /**< shell读函数 */
-    signed short (*write)(const char *, unsigned short);        /**< shell写函数 */
+    signed short (*write)(char *, unsigned short);              /**< shell写函数 */
 #if SHELL_USING_LOCK == 1
     int (*lock)(struct shell_def *);                              /**< shell 加锁 */
     int (*unlock)(struct shell_def *);                            /**< shell 解锁 */
@@ -461,3 +461,4 @@ void *shellCompanionGet(Shell *shell, int id);
 
 #endif
 
+