Merge pull request #3 from RT-Thread/master

sync

34 files changed, 683 insertions, 620 deletions

diff --git a/components/libc/compilers/armlibc/README.md b/components/libc/compilers/armlibc/README.md
new file mode 100644
index 0000000000..4d2a73b6be
--- /dev/null
+++ b/components/libc/compilers/armlibc/README.md
@@ -0,0 +1,9 @@
+# ARMLIB (Keil-MDK) porting for RT-Thread
+
+Please define RT_USING_LIBC and compile RT-Thread with Keil-MDK compiler.
+
+
+
+## More Information
+
+https://www.keil.com/support/man/docs/armlib/
\ No newline at end of file
diff --git a/components/libc/compilers/armlibc/SConscript b/components/libc/compilers/armlibc/SConscript
index 081efa7358..52f7a6d93a 100644
--- a/components/libc/compilers/armlibc/SConscript
+++ b/components/libc/compilers/armlibc/SConscript
@@ -14,7 +14,7 @@ if GetDepend('RT_USING_DFS') == False:
 if GetDepend('RT_USING_MODULE') == False:
     SrcRemove(src, ['libc_syms.c'])
 
-if rtconfig.PLATFORM == 'armcc':
+if rtconfig.PLATFORM == 'armcc' or rtconfig.PLATFORM == 'armclang':
     group = DefineGroup('libc', src, depend = ['RT_USING_LIBC'], 
         CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
 
diff --git a/components/libc/compilers/armlibc/fcntl.h b/components/libc/compilers/armlibc/fcntl.h
index 80cf1b4409..3e650a8471 100644
--- a/components/libc/compilers/armlibc/fcntl.h
+++ b/components/libc/compilers/armlibc/fcntl.h
@@ -9,6 +9,8 @@
 #ifndef FCNTL_H__
 #define FCNTL_H__
 
+#include <rtconfig.h>
+
 #ifdef RT_USING_DFS
 #include <dfs_posix.h>
 #endif
diff --git a/components/libc/compilers/armlibc/libc.h b/components/libc/compilers/armlibc/libc.h
index 158fe06c3e..b9b1b6212d 100644
--- a/components/libc/compilers/armlibc/libc.h
+++ b/components/libc/compilers/armlibc/libc.h
@@ -12,11 +12,17 @@
 
 #include <stddef.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 int libc_system_init(void);
 
 int libc_stdio_set_console(const char* device_name, int mode);
 int libc_stdio_get_console(void);
-int libc_stdio_read (void *buffer, size_t size);
-int libc_stdio_write(const void *buffer, size_t size);
+int libc_stdio_read(void* buffer, size_t size);
+int libc_stdio_write(const void* buffer, size_t size);
+#ifdef __cplusplus
+}
+#endif
 
 #endif
diff --git a/components/libc/compilers/armlibc/stubs.c b/components/libc/compilers/armlibc/stubs.c
index 6e9f13d143..b4cc13799e 100644
--- a/components/libc/compilers/armlibc/stubs.c
+++ b/components/libc/compilers/armlibc/stubs.c
@@ -9,6 +9,8 @@
  * 2013-11-24     aozima       fixed _sys_read()/_sys_write() issues.
  * 2014-08-03     bernard      If using msh, use system() implementation
  *                             in msh.
+ * 2020-08-05     Meco Man     fixed _sys_flen() compiling-warning when 
+ *                             RT_USING_DFS is not defined
  */
 
 #include <string.h>
@@ -251,7 +253,7 @@ void _ttywrch(int ch)
 #endif
 }
 
-void _sys_exit(int return_code)
+RT_WEAK void _sys_exit(int return_code)
 {
     /* TODO: perhaps exit the thread which is invoking this function */
     while (1);
@@ -265,12 +267,25 @@ void _sys_exit(int return_code)
  */
 long _sys_flen(FILEHANDLE fh)
 {
+#ifdef RT_USING_DFS
+    struct stat stat;
+
+    if (fh < STDERR)
+        return -1;
+
+    fstat(fh, &stat);
+    return stat.st_size;
+#else
     return -1;
+#endif
 }
 
 int _sys_istty(FILEHANDLE fh)
 {
-    return 0;
+    if((STDIN <= fh) && (fh <= STDERR))
+        return 1;
+    else
+        return 0;
 }
 
 int remove(const char *filename)
diff --git a/components/libc/compilers/armlibc/termios.h b/components/libc/compilers/armlibc/sys/ioctl.h
index 1956121225..033a57014a 100644
--- a/components/libc/compilers/armlibc/termios.h
+++ b/components/libc/compilers/armlibc/sys/ioctl.h
@@ -5,11 +5,11 @@
  *
  * Change Logs:
  * Date           Author       Notes
+ * 2020-09-01     Meco Man     First Version
  */
-#ifndef _TERMIOS_H__
-#define _TERMIOS_H__
+#ifndef _SYS_IOCTL_H
+#define _SYS_IOCTL_H
+
 
-#include <sys/types.h>
-#include <posix_termios.h>
 
 #endif
diff --git a/components/libc/compilers/armlibc/sys/time.h b/components/libc/compilers/armlibc/sys/time.h
deleted file mode 100644
index bac122e183..0000000000
--- a/components/libc/compilers/armlibc/sys/time.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright (c) 2006-2018, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- */
-#ifndef _SYS_TIME_H_
-#define _SYS_TIME_H_
-
-#include <time.h>
-#include <sys/types.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#ifndef _TIMEVAL_DEFINED
-#define _TIMEVAL_DEFINED
-/*
- * Structure returned by gettimeofday(2) system call,
- * and used in other calls.
- */
-struct timeval {
-    long    tv_sec;     /* seconds */
-    long    tv_usec;    /* and microseconds */
-};
-#endif /* _TIMEVAL_DEFINED */
-
-#ifndef _TIMESPEC_DEFINED
-#define _TIMESPEC_DEFINED
-/*
- * Structure defined by POSIX.1b to be like a timeval.
- */
-struct timespec {
-    time_t  tv_sec;     /* seconds */
-    long    tv_nsec;    /* and nanoseconds */
-};
-#endif /* _TIMESPEC_DEFINED */ 
-
-struct timezone {
-  int tz_minuteswest;   /* minutes west of Greenwich */
-  int tz_dsttime;       /* type of dst correction */
-};
-
-int gettimeofday(struct timeval *tp, void *ignore);
-struct tm *gmtime_r(const time_t *timep, struct tm *r);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _SYS_TIME_H_ */
diff --git a/components/libc/compilers/armlibc/sys/types.h b/components/libc/compilers/armlibc/sys/types.h
index 4c76dfc429..2aad77c99d 100644
--- a/components/libc/compilers/armlibc/sys/types.h
+++ b/components/libc/compilers/armlibc/sys/types.h
@@ -5,16 +5,20 @@
  *
  * Change Logs:
  * Date           Author       Notes
+ * 2020-09-05 Meco Man  fix bugs
  */
 #ifndef __TYPES_H__
 #define __TYPES_H__
 
 #include <stdint.h>
-#include <rtthread.h>
 
-typedef rt_int32_t clockid_t;
-typedef rt_int32_t key_t;       /* Used for interprocess communication. */
-typedef rt_int32_t pid_t;       /* Used for process IDs and process group IDs. */
-typedef signed long ssize_t;    /* Used for a count of bytes or an error indication. */
+typedef int32_t clockid_t;
+typedef int32_t key_t;       /* Used for interprocess communication. */
+typedef int32_t pid_t;       /* Used for process IDs and process group IDs. */
+#ifndef ARCH_CPU_64BIT
+typedef signed int   ssize_t;  /* Used for a count of bytes or an error indication. */
+#else
+typedef long signed int   ssize_t;  /* Used for a count of bytes or an error indication. */
+#endif
 
 #endif
diff --git a/components/libc/compilers/armlibc/sys/unistd.h b/components/libc/compilers/armlibc/sys/unistd.h
index 33f0561e72..524de2cf83 100644
--- a/components/libc/compilers/armlibc/sys/unistd.h
+++ b/components/libc/compilers/armlibc/sys/unistd.h
@@ -36,14 +36,36 @@
 #define _FNDELAY    _FNONBLOCK  /* non blocking I/O (4.2 style) */
 #define _FNOCTTY    0x8000  /* don't assign a ctty on this open */
 
+
+#ifndef O_RDONLY
 #define O_RDONLY    0       /* +1 == FREAD */
+#endif
+#ifndef O_WRONLY
 #define O_WRONLY    1       /* +1 == FWRITE */
+#endif
+#ifndef O_RDWR
 #define O_RDWR      2       /* +1 == FREAD|FWRITE */
+#endif
+#ifndef O_APPEND
 #define O_APPEND    _FAPPEND
+#endif
+#ifndef O_CREAT
 #define O_CREAT     _FCREAT
+#endif
+#ifndef O_TRUNC
 #define O_TRUNC     _FTRUNC
+#endif
+#ifndef O_EXCL
 #define O_EXCL      _FEXCL
+#endif
+#ifndef O_SYNC
 #define O_SYNC      _FSYNC
 #endif
 
+#endif
+
+
+int     isatty      (int fd);
+char *  ttyname     (int desc);
+
 #endif /* _SYS_UNISTD_H */
diff --git a/components/libc/compilers/armlibc/time.c b/components/libc/compilers/armlibc/time.c
deleted file mode 100644
index 29c5c6cdd2..0000000000
--- a/components/libc/compilers/armlibc/time.c
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Copyright (c) 2006-2018, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- */
-#include <sys/time.h>
-#include <rtthread.h>
-
-#ifdef RT_USING_DEVICE
-int gettimeofday(struct timeval *tp, void *ignore)
-{
-    time_t time;
-    rt_device_t device;
-
-    device = rt_device_find("rtc");
-    if (device != RT_NULL)
-    {
-        rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
-        if (tp != RT_NULL)
-        {
-            tp->tv_sec = time;
-            tp->tv_usec = 0;
-        }
-
-        return time;
-    }
-
-    return 0;
-}
-#endif
-
-/**
- * Returns the current time.
- *
- * @param time_t * t the timestamp pointer, if not used, keep NULL.
- *
- * @return time_t return timestamp current.
- *
- */
-/* for IAR 6.2 later Compiler */
-#if defined (__IAR_SYSTEMS_ICC__) &&  (__VER__) >= 6020000
-#pragma module_name = "?time"
-time_t (__time32)(time_t *t) /* Only supports 32-bit timestamp */
-#else
-time_t time(time_t *t)
-#endif
-{
-    time_t time_now = 0;
-
-#ifdef RT_USING_RTC
-    static rt_device_t device = RT_NULL;
-
-    /* optimization: find rtc device only first. */
-    if (device == RT_NULL)
-    {
-        device = rt_device_find("rtc");
-    }
-
-    /* read timestamp from RTC device. */
-    if (device != RT_NULL)
-    {
-        if (rt_device_open(device, 0) == RT_EOK)
-        {
-            rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time_now);
-            rt_device_close(device);
-        }
-    }
-#endif /* RT_USING_RTC */
-
-    /* if t is not NULL, write timestamp to *t */
-    if (t != RT_NULL)
-    {
-        *t = time_now;
-    }
-
-    return time_now;
-}
-
-RT_WEAK clock_t clock(void)
-{
-    return rt_tick_get();
-}
diff --git a/components/libc/compilers/armlibc/unistd.h b/components/libc/compilers/armlibc/unistd.h
index 70187722d8..736fc219a8 100644
--- a/components/libc/compilers/armlibc/unistd.h
+++ b/components/libc/compilers/armlibc/unistd.h
@@ -7,3 +7,4 @@
  * Date           Author       Notes
  */
 #include "sys/unistd.h"
+
diff --git a/components/libc/compilers/common/SConscript b/components/libc/compilers/common/SConscript
index 02bf49941d..2407301405 100644
--- a/components/libc/compilers/common/SConscript
+++ b/components/libc/compilers/common/SConscript
@@ -2,11 +2,21 @@ from building import *
 
 Import('rtconfig')
 
-src   = Glob('*.c')
+src   = []
 cwd   = GetCurrentDir()
 group = []
 CPPPATH = [cwd]
 
-group = DefineGroup('libc', src, depend = ['RT_USING_LIBC'], CPPPATH = CPPPATH)
+if GetDepend('RT_USING_LIBC'):
+        src += Glob('*.c')      
+else:
+        if GetDepend('RT_LIBC_USING_TIME') and not GetDepend('RT_USING_MINILIBC'):
+                src += ['time.c']
+
+if GetDepend('RT_USING_POSIX') == False:
+        SrcRemove(src, ['unistd.c'])
+
+if not GetDepend('RT_USING_MINILIBC') and (GetDepend('RT_USING_LIBC') or GetDepend('RT_LIBC_USING_TIME')):
+	group = DefineGroup('libc', src, depend = [''], CPPPATH = CPPPATH)
 
 Return('group')
diff --git a/components/libc/compilers/common/gmtime_r.c b/components/libc/compilers/common/gmtime_r.c
deleted file mode 100644
index dff251ab6c..0000000000
--- a/components/libc/compilers/common/gmtime_r.c
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright (c) 2006-2018, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2018-10-26     zylx         first version
- */
-
-#if defined(__CC_ARM) || defined(__CLANG_ARM) || defined (__IAR_SYSTEMS_ICC__)  
-#include <sys/time.h>
-
-/* seconds per day */
-#define SPD 24*60*60
-
-/* days per month -- nonleap! */
-const short __spm[13] =
-{
-    0,
-    (31),
-    (31 + 28),
-    (31 + 28 + 31),
-    (31 + 28 + 31 + 30),
-    (31 + 28 + 31 + 30 + 31),
-    (31 + 28 + 31 + 30 + 31 + 30),
-    (31 + 28 + 31 + 30 + 31 + 30 + 31),
-    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31),
-    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30),
-    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31),
-    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30),
-    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31),
-};
-
-int __isleap(int year)
-{
-    /* every fourth year is a leap year except for century years that are
-     * not divisible by 400. */
-    /*  return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); */
-    return (!(year % 4) && ((year % 100) || !(year % 400)));
-}
-
-/**
- * This function will convert Time (Restartable)
- *
- * @param timep the timestamp
- * @param the structure to stores information
- *
- * @return the structure to stores information
- *
- */
-struct tm *gmtime_r(const time_t *timep, struct tm *r)
-{
-    time_t i;
-    register time_t work = *timep % (SPD);
-    r->tm_sec = work % 60;
-    work /= 60;
-    r->tm_min = work % 60;
-    r->tm_hour = work / 60;
-    work = *timep / (SPD);
-    r->tm_wday = (4 + work) % 7;
-    for (i = 1970;; ++i)
-    {
-        register time_t k = __isleap(i) ? 366 : 365;
-        if (work >= k)
-            work -= k;
-        else
-            break;
-    }
-    r->tm_year = i - 1900;
-    r->tm_yday = work;
-
-    r->tm_mday = 1;
-    if (__isleap(i) && (work > 58))
-    {
-        if (work == 59)
-            r->tm_mday = 2; /* 29.2. */
-        work -= 1;
-    }
-
-    for (i = 11; i && (__spm[i] > work); --i)
-        ;
-    r->tm_mon = i;
-    r->tm_mday += work - __spm[i];
-    return r;
-}
-#endif /* end of __CC_ARM or __CLANG_ARM or __IAR_SYSTEMS_ICC__ */
-
diff --git a/components/libc/compilers/common/readme.md b/components/libc/compilers/common/readme.md
new file mode 100644
index 0000000000..99797d933c
--- /dev/null
+++ b/components/libc/compilers/common/readme.md
@@ -0,0 +1,10 @@
+## Attentions
+
+1. This folder is "common" for armlibc newlibc and dlib. It's not "common" for minilibc.
+
+2. If you want to add new .c files, please do not forget to fix SConscript file too. eg:
+
+```python
+if GetDepend('RT_USING_POSIX') == False:
+        SrcRemove(src, ['unistd.c'])
+```
\ No newline at end of file
diff --git a/components/libc/compilers/dlib/sys/time.h b/components/libc/compilers/common/sys/time.h
index baf566936b..22f1c17f5e 100644
--- a/components/libc/compilers/dlib/sys/time.h
+++ b/components/libc/compilers/common/sys/time.h
@@ -5,17 +5,25 @@
  *
  * Change Logs:
  * Date           Author       Notes
+ * 2020-09-07     Meco Man     combine gcc armcc iccarm
  */
 #ifndef _SYS_TIME_H_
 #define _SYS_TIME_H_
 
 #include <time.h>
-#include <sys/types.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/*
+ * Skip define timespec for IAR version over 8.10.1 where __VER__ is 8010001.
+ */
+#if defined ( __ICCARM__ ) && (__VER__ >= 8010001)
+#define _TIMESPEC_DEFINED
+#endif
+
+
 #ifndef _TIMEVAL_DEFINED
 #define _TIMEVAL_DEFINED
 /*
@@ -28,23 +36,6 @@ struct timeval {
 };
 #endif /* _TIMEVAL_DEFINED */
 
-/*
- * Skip define timespec for IAR version over 8.10.1 where __VER__ is 8010001.
- */
-#if defined ( __ICCARM__ ) && (__VER__ >= 8010001)
-#define _TIMESPEC_DEFINED
-#endif
-
-#ifndef _TIMESPEC_DEFINED
-#define _TIMESPEC_DEFINED
-/*
- * Structure defined by POSIX.1b to be like a timeval.
- */
-struct timespec {
-    time_t  tv_sec;     /* seconds */
-    long    tv_nsec;    /* and nanoseconds */
-};
-#endif /* _TIMESPEC_DEFINED */ 
 
 struct timezone {
   int tz_minuteswest;   /* minutes west of Greenwich */
diff --git a/components/libc/compilers/dlib/termios.h b/components/libc/compilers/common/termios.h
index 1956121225..ee2b4d5718 100644
--- a/components/libc/compilers/dlib/termios.h
+++ b/components/libc/compilers/common/termios.h
@@ -9,7 +9,9 @@
 #ifndef _TERMIOS_H__
 #define _TERMIOS_H__
 
+#ifdef RT_USING_POSIX_TERMIOS
 #include <sys/types.h>
 #include <posix_termios.h>
+#endif
 
 #endif
diff --git a/components/libc/compilers/common/time.c b/components/libc/compilers/common/time.c
new file mode 100644
index 0000000000..99dab71eb4
--- /dev/null
+++ b/components/libc/compilers/common/time.c
@@ -0,0 +1,292 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2019-08-21     zhangjun     copy from minilibc
+ * 2020-09-07     Meco Man     combine gcc armcc iccarm
+ */
+
+#include <sys/time.h>
+#include <rtthread.h>
+
+#if !defined (__IAR_SYSTEMS_ICC__)
+
+/* days per month -- nonleap! */
+const short __spm[13] =
+{
+    0,
+    (31),
+    (31 + 28),
+    (31 + 28 + 31),
+    (31 + 28 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31),
+};
+static const char days[] = "Sun Mon Tue Wed Thu Fri Sat ";
+static const char months[] = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ";
+
+/* seconds per day */
+#define SPD 24*60*60
+
+int __isleap(int year)
+{
+    /* every fourth year is a leap year except for century years that are
+     * not divisible by 400. */
+    /*  return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); */
+    return (!(year % 4) && ((year % 100) || !(year % 400)));
+}
+
+struct tm *gmtime_r(const time_t *timep, struct tm *r)
+{
+    time_t i;
+    register time_t work = *timep % (SPD);
+    r->tm_sec = work % 60;
+    work /= 60;
+    r->tm_min = work % 60;
+    r->tm_hour = work / 60;
+    work = *timep / (SPD);
+    r->tm_wday = (4 + work) % 7;
+    for (i = 1970;; ++i)
+    {
+        register time_t k = __isleap(i) ? 366 : 365;
+        if (work >= k)
+            work -= k;
+        else
+            break;
+    }
+    r->tm_year = i - 1900;
+    r->tm_yday = work;
+
+    r->tm_mday = 1;
+    if (__isleap(i) && (work > 58))
+    {
+        if (work == 59)
+            r->tm_mday = 2; /* 29.2. */
+        work -= 1;
+    }
+
+    for (i = 11; i && (__spm[i] > work); --i)
+        ;
+    r->tm_mon = i;
+    r->tm_mday += work - __spm[i];
+    return r;
+}
+
+struct tm* gmtime(const time_t* t)
+{
+    static struct tm tmp;
+    return gmtime_r(t, &tmp);
+}
+
+/*TODO timezone is not supprt now */
+struct tm* localtime_r(const time_t* t, struct tm* r)
+{
+    return gmtime_r(t, r);
+}
+
+struct tm* localtime(const time_t* t)
+{
+    static struct tm tmp;
+    return localtime_r(t, &tmp);
+}
+
+time_t mktime(struct tm * const t)
+{
+    register time_t day;
+    register time_t i;
+    register time_t years = t->tm_year - 70;
+
+    if (t->tm_sec > 60)
+    {
+        t->tm_min += t->tm_sec / 60;
+        t->tm_sec %= 60;
+    }
+    if (t->tm_min > 60)
+    {
+        t->tm_hour += t->tm_min / 60;
+        t->tm_min %= 60;
+    }
+    if (t->tm_hour > 24)
+    {
+        t->tm_mday += t->tm_hour / 24;
+        t->tm_hour %= 24;
+    }
+    if (t->tm_mon > 12)
+    {
+        t->tm_year += t->tm_mon / 12;
+        t->tm_mon %= 12;
+    }
+    while (t->tm_mday > __spm[1 + t->tm_mon])
+    {
+        if (t->tm_mon == 1 && __isleap(t->tm_year + 1900))
+        {
+            --t->tm_mday;
+        }
+        t->tm_mday -= __spm[t->tm_mon];
+        ++t->tm_mon;
+        if (t->tm_mon > 11)
+        {
+            t->tm_mon = 0;
+            ++t->tm_year;
+        }
+    }
+
+    if (t->tm_year < 70)
+        return (time_t) - 1;
+
+    /* Days since 1970 is 365 * number of years + number of leap years since 1970 */
+    day = years * 365 + (years + 1) / 4;
+
+    /* After 2100 we have to substract 3 leap years for every 400 years
+     This is not intuitive. Most mktime implementations do not support
+     dates after 2059, anyway, so we might leave this out for it's
+     bloat. */
+    if (years >= 131)
+    {
+        years -= 131;
+        years /= 100;
+        day -= (years >> 2) * 3 + 1;
+        if ((years &= 3) == 3)
+            years--;
+        day -= years;
+    }
+
+    day += t->tm_yday = __spm[t->tm_mon] + t->tm_mday - 1 +
+                        (__isleap(t->tm_year + 1900) & (t->tm_mon > 1));
+
+    /* day is now the number of days since 'Jan 1 1970' */
+    i = 7;
+    t->tm_wday = (day + 4) % i; /* Sunday=0, Monday=1, ..., Saturday=6 */
+
+    i = 24;
+    day *= i;
+    i = 60;
+    return ((day + t->tm_hour) * i + t->tm_min) * i + t->tm_sec;
+}
+
+static void num2str(char *c, int i)
+{
+    c[0] = i / 10 + '0';
+    c[1] = i % 10 + '0';
+}
+
+char* asctime_r(const struct tm *t, char *buf)
+{
+    /* "Wed Jun 30 21:49:08 1993\n" */
+    *(int*) buf = *(int*) (days + (t->tm_wday << 2));
+    *(int*) (buf + 4) = *(int*) (months + (t->tm_mon << 2));
+    num2str(buf + 8, t->tm_mday);
+    if (buf[8] == '0')
+        buf[8] = ' ';
+    buf[10] = ' ';
+    num2str(buf + 11, t->tm_hour);
+    buf[13] = ':';
+    num2str(buf + 14, t->tm_min);
+    buf[16] = ':';
+    num2str(buf + 17, t->tm_sec);
+    buf[19] = ' ';
+    num2str(buf + 20, (t->tm_year + 1900) / 100);
+    num2str(buf + 22, (t->tm_year + 1900) % 100);
+    buf[24] = '\n';
+    return buf;
+}
+
+char* asctime(const struct tm *timeptr)
+{
+    static char buf[25];
+    return asctime_r(timeptr, buf);
+}
+
+char* ctime(const time_t *timep)
+{
+    return asctime(localtime(timep));
+}
+
+#endif /* __IAR_SYSTEMS_ICC__ */
+
+int gettimeofday(struct timeval *tp, void *ignore)
+{
+    time_t time = 0;
+#ifdef RT_USING_DEVICE
+    rt_device_t device;
+    device = rt_device_find("rtc");
+    RT_ASSERT(device != RT_NULL);
+    rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
+    if (tp != RT_NULL)
+    {
+        tp->tv_sec = time;
+        tp->tv_usec = 0;
+    }
+#else
+    tv->tv_sec = 0;
+    tv->tv_usec = 0;
+#endif
+
+    return time;
+}
+
+
+/**
+ * Returns the current time.
+ *
+ * @param time_t * t the timestamp pointer, if not used, keep NULL.
+ *
+ * @return time_t return timestamp current.
+ *
+ */
+/* for IAR 6.2 later Compiler */
+#if defined (__IAR_SYSTEMS_ICC__) &&  (__VER__) >= 6020000
+#pragma module_name = "?time"
+#if _DLIB_TIME_USES_64
+time_t __time64(time_t *t) 
+#else
+time_t __time32(time_t *t) 
+#endif
+#else
+time_t time(time_t *t)
+#endif
+{
+    time_t time_now = 0;
+
+#ifdef RT_USING_RTC
+    static rt_device_t device = RT_NULL;
+
+    /* optimization: find rtc device only first. */
+    if (device == RT_NULL)
+    {
+        device = rt_device_find("rtc");
+    }
+
+    /* read timestamp from RTC device. */
+    if (device != RT_NULL)
+    {
+        if (rt_device_open(device, 0) == RT_EOK)
+        {
+            rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time_now);
+            rt_device_close(device);
+        }
+    }
+#endif /* RT_USING_RTC */
+
+    /* if t is not NULL, write timestamp to *t */
+    if (t != RT_NULL)
+    {
+        *t = time_now;
+    }
+
+    return time_now;
+}
+
+RT_WEAK clock_t clock(void)
+{
+    return rt_tick_get();
+}
diff --git a/components/libc/compilers/common/unistd.c b/components/libc/compilers/common/unistd.c
new file mode 100644
index 0000000000..df970b2b59
--- /dev/null
+++ b/components/libc/compilers/common/unistd.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2020-09-01     Meco Man     First Version
+ */
+
+#include <unistd.h>
+
+#ifdef RT_USING_POSIX_TERMIOS
+#include "termios.h"
+
+int isatty(int fd)
+{
+    struct termios ts;
+    return(tcgetattr(fd,&ts) != -1);/*true if no error (is a tty)*/
+}
+#endif
+
+char *ttyname(int fd)
+{
+    return "/dev/tty0"; /*TODO: need to add more specific*/
+}
diff --git a/components/libc/compilers/dlib/README.md b/components/libc/compilers/dlib/README.md
index 846eb3f5c0..acd08f9074 100644
--- a/components/libc/compilers/dlib/README.md
+++ b/components/libc/compilers/dlib/README.md
@@ -1,4 +1,9 @@
-Dlib(IAR) porting for RT-Thread.
+# DLIB (IAR) porting for RT-Thread
 
 Please define RT_USING_LIBC and compile RT-Thread with IAR compiler.
 
+
+
+## More Information
+
+http://www.iarsys.co.jp/download/LMS2/arm/7502/ewarm7502doc/arm/doc/EWARM_DevelopmentGuide.ENU.pdf    P.130
\ No newline at end of file
diff --git a/components/libc/compilers/dlib/libc.h b/components/libc/compilers/dlib/libc.h
index 7b2665c32b..5b46bee0c8 100644
--- a/components/libc/compilers/dlib/libc.h
+++ b/components/libc/compilers/dlib/libc.h
@@ -13,11 +13,17 @@
 
 #include <stddef.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 int libc_system_init(void);
 
 int libc_stdio_set_console(const char* device_name, int mode);
 int libc_stdio_get_console(void);
-int libc_stdio_read (void *buffer, size_t size);
-int libc_stdio_write(const void *buffer, size_t size);
+int libc_stdio_read(void* buffer, size_t size);
+int libc_stdio_write(const void* buffer, size_t size);
+#ifdef __cplusplus
+}
+#endif
 
 #endif
diff --git a/components/libc/compilers/dlib/sys/errno.h b/components/libc/compilers/dlib/sys/errno.h
index 1ecb58b74c..1ad4c8acc0 100644
--- a/components/libc/compilers/dlib/sys/errno.h
+++ b/components/libc/compilers/dlib/sys/errno.h
@@ -5,11 +5,12 @@
  *
  * Change Logs:
  * Date           Author       Notes
+ * 2019-07-08     Bernard      The first version
  */
+
 #ifndef SYS_ERRNO_H__
 #define SYS_ERRNO_H__
 
-#include <rtthread.h>
-
+#include <errno.h>
 
 #endif
diff --git a/components/libc/compilers/newlib/termios.h b/components/libc/compilers/dlib/sys/signal.h
index 1956121225..22adb1228b 100644
--- a/components/libc/compilers/newlib/termios.h
+++ b/components/libc/compilers/dlib/sys/signal.h
@@ -5,11 +5,12 @@
  *
  * Change Logs:
  * Date           Author       Notes
+ * 2019-07-08     Bernard      The first version
  */
-#ifndef _TERMIOS_H__
-#define _TERMIOS_H__
 
-#include <sys/types.h>
-#include <posix_termios.h>
+#ifndef SYS_SIGNAL_H__
+#define SYS_SIGNAL_H__
+
+#include <libc/libc_signal.h>
 
 #endif
diff --git a/components/libc/compilers/dlib/sys/types.h b/components/libc/compilers/dlib/sys/types.h
index 4c76dfc429..001ace4dd2 100644
--- a/components/libc/compilers/dlib/sys/types.h
+++ b/components/libc/compilers/dlib/sys/types.h
@@ -15,6 +15,10 @@
 typedef rt_int32_t clockid_t;
 typedef rt_int32_t key_t;       /* Used for interprocess communication. */
 typedef rt_int32_t pid_t;       /* Used for process IDs and process group IDs. */
-typedef signed long ssize_t;    /* Used for a count of bytes or an error indication. */
+#ifndef ARCH_CPU_64BIT
+typedef signed int   ssize_t;  /* Used for a count of bytes or an error indication. */
+#else
+typedef long signed int   ssize_t;  /* Used for a count of bytes or an error indication. */
+#endif
 
 #endif
diff --git a/components/libc/compilers/dlib/sys/unistd.h b/components/libc/compilers/dlib/sys/unistd.h
index 5985a42996..9564daba8d 100644
--- a/components/libc/compilers/dlib/sys/unistd.h
+++ b/components/libc/compilers/dlib/sys/unistd.h
@@ -34,14 +34,10 @@
 #define	_FNDELAY	_FNONBLOCK	/* non blocking I/O (4.2 style) */
 #define	_FNOCTTY	0x8000	/* don't assign a ctty on this open */
 
-#define	O_RDONLY	0		/* +1 == FREAD */
-#define	O_WRONLY	1		/* +1 == FWRITE */
-#define	O_RDWR		2		/* +1 == FREAD|FWRITE */
-#define	O_APPEND	_FAPPEND
-#define	O_CREAT		_FCREAT
-#define	O_TRUNC		_FTRUNC
-#define	O_EXCL		_FEXCL
-#define O_SYNC		_FSYNC
 #endif
 
+
+int     isatty      (int fd);
+char *  ttyname     (int desc);
+
 #endif /* _SYS_UNISTD_H */
diff --git a/components/libc/compilers/dlib/time.c b/components/libc/compilers/dlib/time.c
deleted file mode 100644
index 87574df851..0000000000
--- a/components/libc/compilers/dlib/time.c
+++ /dev/null
@@ -1,89 +0,0 @@
-/*
- * Copyright (c) 2006-2018, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- */
-#include <sys/time.h>
-#include <rtthread.h>
-
-#ifdef RT_USING_DEVICE
-int gettimeofday(struct timeval *tp, void *ignore)
-{
-    time_t time;
-    rt_device_t device;
-
-    device = rt_device_find("rtc");
-    if (device != RT_NULL)
-    {
-        rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
-        if (tp != RT_NULL)
-        {
-            tp->tv_sec = time;
-            tp->tv_usec = 0;
-        }
-
-        return time;
-    }
-
-    return 0;
-}
-#endif
-
-/**
- * Returns the current time.
- *
- * @param time_t * t the timestamp pointer, if not used, keep NULL.
- *
- * @return time_t return timestamp current.
- *
- */
-#pragma module_name = "?time"
-#if _DLIB_TIME_USES_64
-time_t __time64(time_t *t)
-#else
-/* for IAR 6.2 later Compiler */
-#if defined (__IAR_SYSTEMS_ICC__) &&  (__VER__) >= 6020000
-time_t __time32(time_t *t)
-#else
-time_t time(time_t *t)
-#endif
-#endif
-{
-  time_t time_now = 0;
-  
-#ifdef RT_USING_RTC
-  static rt_device_t device = RT_NULL;
-  
-  /* optimization: find rtc device only first. */
-  if (device == RT_NULL)
-  {
-    device = rt_device_find("rtc");
-  }
-  
-  /* read timestamp from RTC device. */
-  if (device != RT_NULL)
-  {
-    if (rt_device_open(device, 0) == RT_EOK)
-    {
-      rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time_now);
-      rt_device_close(device);
-    }
-  }
-#endif /* RT_USING_RTC */
-  
-  /* if t is not NULL, write timestamp to *t */
-  if (t != RT_NULL)
-  {
-    *t = time_now;
-  }
-  
-  return time_now;
-}
-
-RT_WEAK clock_t clock(void)
-{
-    return rt_tick_get();
-}
diff --git a/components/libc/compilers/minilibc/SConscript b/components/libc/compilers/minilibc/SConscript
index 518d800571..dec657028f 100644
--- a/components/libc/compilers/minilibc/SConscript
+++ b/components/libc/compilers/minilibc/SConscript
@@ -8,7 +8,7 @@ group = []
 CPPPATH = [cwd]
 CPPDEFINES = ['RT_USING_MINILIBC']
 
-if rtconfig.PLATFORM == 'gcc' and rtconfig.ARCH != 'sim' and not GetDepend('RT_USING_LIBC'):
+if rtconfig.PLATFORM == 'gcc' and rtconfig.ARCH != 'sim' and not GetDepend('RT_USING_LIBC') and GetDepend('RT_USING_MINILIBC'):
     group = DefineGroup('libc', src, depend = [''],
         CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
 
diff --git a/components/libc/compilers/minilibc/math.h b/components/libc/compilers/minilibc/math.h
index 9ddb9c859b..49b80d8219 100644
--- a/components/libc/compilers/minilibc/math.h
+++ b/components/libc/compilers/minilibc/math.h
@@ -14,4 +14,7 @@
 double sin(double x);
 double cos(double x);
 
+typedef float float_t;
+typedef double double_t;
+
 #endif
diff --git a/components/libc/compilers/minilibc/signal.h b/components/libc/compilers/minilibc/signal.h
new file mode 100644
index 0000000000..f52f1e1009
--- /dev/null
+++ b/components/libc/compilers/minilibc/signal.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2017-09-12     Bernard      The first version
+ */
+
+#ifndef SIGNAL_H__
+#define SIGNAL_H__
+
+#include <libc/libc_signal.h>
+
+#define SIG_DFL ((_sig_func_ptr)0)  /* Default action */
+#define SIG_IGN ((_sig_func_ptr)1)  /* Ignore action */
+#define SIG_ERR ((_sig_func_ptr)-1) /* Error return */
+
+#endif
diff --git a/components/libc/compilers/minilibc/sys/types.h b/components/libc/compilers/minilibc/sys/types.h
index 0c00a79d1e..746235273c 100644
--- a/components/libc/compilers/minilibc/sys/types.h
+++ b/components/libc/compilers/minilibc/sys/types.h
@@ -8,18 +8,23 @@
  */
 #ifndef __TYPES_H__
 #define __TYPES_H__
+#include <rtconfig.h>
 
 typedef long        off_t;
-typedef unsigned long size_t;
-typedef signed long   ssize_t;      /* Used for a count of bytes or an error indication. */
+
+#ifndef ARCH_CPU_64BIT
+typedef unsigned int size_t;
+typedef signed int   ssize_t;  /* Used for a count of bytes or an error indication. */
+#else
+typedef long unsigned int size_t;
+typedef long signed int   ssize_t;  /* Used for a count of bytes or an error indication. */
+#endif
 
 typedef unsigned char  u_char;
 typedef unsigned short u_short;
 typedef unsigned int   u_int;
 typedef unsigned long  u_long;
 
-typedef int mode_t;
-
 typedef unsigned long clockid_t;
 typedef int pid_t;
 
diff --git a/components/libc/compilers/minilibc/time.c b/components/libc/compilers/minilibc/time.c
index 508558bafc..25e8f0e310 100644
--- a/components/libc/compilers/minilibc/time.c
+++ b/components/libc/compilers/minilibc/time.c
@@ -11,20 +11,20 @@
 
 /* days per month -- nonleap! */
 const short __spm[13] =
-  { 0,
+{   0,
     (31),
-    (31+28),
-    (31+28+31),
-    (31+28+31+30),
-    (31+28+31+30+31),
-    (31+28+31+30+31+30),
-    (31+28+31+30+31+30+31),
-    (31+28+31+30+31+30+31+31),
-    (31+28+31+30+31+30+31+31+30),
-    (31+28+31+30+31+30+31+31+30+31),
-    (31+28+31+30+31+30+31+31+30+31+30),
-    (31+28+31+30+31+30+31+31+30+31+30+31),
-  };
+    (31 + 28),
+    (31 + 28 + 31),
+    (31 + 28 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30),
+    (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31),
+};
 static long int timezone;
 static const char days[] = "Sun Mon Tue Wed Thu Fri Sat ";
 static const char months[] = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ";
@@ -34,196 +34,193 @@ static const char months[] = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ";
 
 int __isleap(int year)
 {
-	/* every fourth year is a leap year except for century years that are
-	 * not divisible by 400. */
-	/*  return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); */
-	return (!(year % 4) && ((year % 100) || !(year % 400)));
+    /* every fourth year is a leap year except for century years that are
+     * not divisible by 400. */
+    /*  return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); */
+    return (!(year % 4) && ((year % 100) || !(year % 400)));
 }
 
 struct tm *gmtime_r(const time_t *timep, struct tm *r)
 {
-	time_t i;
-	register time_t work = *timep % (SPD);
-	r->tm_sec = work % 60;
-	work /= 60;
-	r->tm_min = work % 60;
-	r->tm_hour = work / 60;
-	work = *timep / (SPD);
-	r->tm_wday = (4 + work) % 7;
-	for (i = 1970;; ++i)
-	{
-		register time_t k = __isleap(i) ? 366 : 365;
-		if (work >= k)
-			work -= k;
-		else
-			break;
-	}
-	r->tm_year = i - 1900;
-	r->tm_yday = work;
+    time_t i;
+    register time_t work = *timep % (SPD);
+    r->tm_sec = work % 60;
+    work /= 60;
+    r->tm_min = work % 60;
+    r->tm_hour = work / 60;
+    work = *timep / (SPD);
+    r->tm_wday = (4 + work) % 7;
+    for (i = 1970;; ++i)
+    {
+        register time_t k = __isleap(i) ? 366 : 365;
+        if (work >= k)
+            work -= k;
+        else
+            break;
+    }
+    r->tm_year = i - 1900;
+    r->tm_yday = work;
 
-	r->tm_mday = 1;
-	if (__isleap(i) && (work > 58))
-	{
-		if (work == 59)
-			r->tm_mday = 2; /* 29.2. */
-		work -= 1;
-	}
+    r->tm_mday = 1;
+    if (__isleap(i) && (work > 58))
+    {
+        if (work == 59)
+            r->tm_mday = 2; /* 29.2. */
+        work -= 1;
+    }
 
-	for (i = 11; i && (__spm[i] > work); --i)
-		;
-	r->tm_mon = i;
-	r->tm_mday += work - __spm[i];
-	return r;
+    for (i = 11; i && (__spm[i] > work); --i)
+        ;
+    r->tm_mon = i;
+    r->tm_mday += work - __spm[i];
+    return r;
 }
 
 struct tm* localtime_r(const time_t* t, struct tm* r)
 {
-	time_t tmp;
-	struct timezone tz = {0};
-	gettimeofday(0, &tz);
-	timezone = tz.tz_minuteswest * 60L;
-	tmp = *t + timezone;
-	return gmtime_r(&tmp, r);
+    time_t tmp;
+    struct timezone tz = {0};
+    gettimeofday(0, &tz);
+    timezone = tz.tz_minuteswest * 60L;
+    tmp = *t + timezone;
+    return gmtime_r(&tmp, r);
 }
 
 struct tm* localtime(const time_t* t)
 {
-	static struct tm tmp;
-	return localtime_r(t, &tmp);
+    static struct tm tmp;
+    return localtime_r(t, &tmp);
 }
 
 time_t mktime(struct tm * const t)
 {
-	register time_t day;
-	register time_t i;
-	register time_t years = t->tm_year - 70;
+    register time_t day;
+    register time_t i;
+    register time_t years = t->tm_year - 70;
 
-	if (t->tm_sec > 60)
-	{
-		t->tm_min += t->tm_sec / 60;
-		t->tm_sec %= 60;
-	}
-	if (t->tm_min > 60)
-	{
-		t->tm_hour += t->tm_min / 60;
-		t->tm_min %= 60;
-	}
-	if (t->tm_hour > 24)
-	{
-		t->tm_mday += t->tm_hour / 24;
-		t->tm_hour %= 24;
-	}
-	if (t->tm_mon > 12)
-	{
-		t->tm_year += t->tm_mon / 12;
-		t->tm_mon %= 12;
-	}
-	while (t->tm_mday > __spm[1 + t->tm_mon])
-	{
-		if (t->tm_mon == 1 && __isleap(t->tm_year + 1900))
-		{
-			--t->tm_mday;
-		}
-		t->tm_mday -= __spm[t->tm_mon];
-		++t->tm_mon;
-		if (t->tm_mon > 11)
-		{
-			t->tm_mon = 0;
-			++t->tm_year;
-		}
-	}
+    if (t->tm_sec > 60)
+    {
+        t->tm_min += t->tm_sec / 60;
+        t->tm_sec %= 60;
+    }
+    if (t->tm_min > 60)
+    {
+        t->tm_hour += t->tm_min / 60;
+        t->tm_min %= 60;
+    }
+    if (t->tm_hour > 24)
+    {
+        t->tm_mday += t->tm_hour / 24;
+        t->tm_hour %= 24;
+    }
+    if (t->tm_mon > 12)
+    {
+        t->tm_year += t->tm_mon / 12;
+        t->tm_mon %= 12;
+    }
+    while (t->tm_mday > __spm[1 + t->tm_mon])
+    {
+        if (t->tm_mon == 1 && __isleap(t->tm_year + 1900))
+        {
+            --t->tm_mday;
+        }
+        t->tm_mday -= __spm[t->tm_mon];
+        ++t->tm_mon;
+        if (t->tm_mon > 11)
+        {
+            t->tm_mon = 0;
+            ++t->tm_year;
+        }
+    }
 
-	if (t->tm_year < 70)
-		return (time_t) -1;
+    if (t->tm_year < 70)
+        return (time_t) - 1;
 
-	/* Days since 1970 is 365 * number of years + number of leap years since 1970 */
-	day = years * 365 + (years + 1) / 4;
+    /* Days since 1970 is 365 * number of years + number of leap years since 1970 */
+    day = years * 365 + (years + 1) / 4;
 
-	/* After 2100 we have to substract 3 leap years for every 400 years
-	 This is not intuitive. Most mktime implementations do not support
-	 dates after 2059, anyway, so we might leave this out for it's
-	 bloat. */
-	if (years >= 131)
-	{
-		years -= 131;
-		years /= 100;
-		day -= (years >> 2) * 3 + 1;
-		if ((years &= 3) == 3)
-			years--;
-		day -= years;
-	}
+    /* After 2100 we have to substract 3 leap years for every 400 years
+     This is not intuitive. Most mktime implementations do not support
+     dates after 2059, anyway, so we might leave this out for it's
+     bloat. */
+    if (years >= 131)
+    {
+        years -= 131;
+        years /= 100;
+        day -= (years >> 2) * 3 + 1;
+        if ((years &= 3) == 3)
+            years--;
+        day -= years;
+    }
 
-	day += t->tm_yday = __spm[t->tm_mon] + t->tm_mday - 1 +
-			(__isleap(t->tm_year + 1900) & (t->tm_mon > 1));
+    day += t->tm_yday = __spm[t->tm_mon] + t->tm_mday - 1 +
+                        (__isleap(t->tm_year + 1900) & (t->tm_mon > 1));
 
-	/* day is now the number of days since 'Jan 1 1970' */
-	i = 7;
-	t->tm_wday = (day + 4) % i; /* Sunday=0, Monday=1, ..., Saturday=6 */
+    /* day is now the number of days since 'Jan 1 1970' */
+    i = 7;
+    t->tm_wday = (day + 4) % i; /* Sunday=0, Monday=1, ..., Saturday=6 */
 
-	i = 24;
-	day *= i;
-	i = 60;
-	return ((day + t->tm_hour) * i + t->tm_min) * i + t->tm_sec;
+    i = 24;
+    day *= i;
+    i = 60;
+    return ((day + t->tm_hour) * i + t->tm_min) * i + t->tm_sec;
 }
 
 static void num2str(char *c, int i)
 {
-	c[0] = i / 10 + '0';
-	c[1] = i % 10 + '0';
+    c[0] = i / 10 + '0';
+    c[1] = i % 10 + '0';
 }
 
 char *asctime_r(const struct tm *t, char *buf)
 {
-	/* "Wed Jun 30 21:49:08 1993\n" */
-	*(int*) buf = *(int*) (days + (t->tm_wday << 2));
-	*(int*) (buf + 4) = *(int*) (months + (t->tm_mon << 2));
-	num2str(buf + 8, t->tm_mday);
-	if (buf[8] == '0')
-		buf[8] = ' ';
-	buf[10] = ' ';
-	num2str(buf + 11, t->tm_hour);
-	buf[13] = ':';
-	num2str(buf + 14, t->tm_min);
-	buf[16] = ':';
-	num2str(buf + 17, t->tm_sec);
-	buf[19] = ' ';
-	num2str(buf + 20, (t->tm_year + 1900) / 100);
-	num2str(buf + 22, (t->tm_year + 1900) % 100);
-	buf[24] = '\n';
-	return buf;
+    /* "Wed Jun 30 21:49:08 1993\n" */
+    *(int*) buf = *(int*) (days + (t->tm_wday << 2));
+    *(int*) (buf + 4) = *(int*) (months + (t->tm_mon << 2));
+    num2str(buf + 8, t->tm_mday);
+    if (buf[8] == '0')
+        buf[8] = ' ';
+    buf[10] = ' ';
+    num2str(buf + 11, t->tm_hour);
+    buf[13] = ':';
+    num2str(buf + 14, t->tm_min);
+    buf[16] = ':';
+    num2str(buf + 17, t->tm_sec);
+    buf[19] = ' ';
+    num2str(buf + 20, (t->tm_year + 1900) / 100);
+    num2str(buf + 22, (t->tm_year + 1900) % 100);
+    buf[24] = '\n';
+    return buf;
 }
 
 char *asctime(const struct tm *timeptr)
 {
-	static char buf[25];
-	return asctime_r(timeptr, buf);
+    static char buf[25];
+    return asctime_r(timeptr, buf);
 }
 
 char *ctime(const time_t *timep)
 {
-	return asctime(localtime(timep));
+    return asctime(localtime(timep));
 }
 
 #ifdef RT_USING_DEVICE
 int gettimeofday(struct timeval *tp, void *ignore)
 {
-	time_t time;
-	rt_device_t device;
+    time_t time;
+    rt_device_t device;
 
-	device = rt_device_find("rtc");
-	if (device != RT_NULL)
-	{
-		rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
-		if (tp != RT_NULL)
-		{
-			tp->tv_sec = time;
-			tp->tv_usec = 0;
-		}
+    device = rt_device_find("rtc");
+    RT_ASSERT(device != RT_NULL);
 
-		return time;
-	}
+    rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
+    if (tp != RT_NULL)
+    {
+        tp->tv_sec = time;
+        tp->tv_usec = 0;
+    }
 
-	return 0;
+    return time;
 }
 #endif
 
diff --git a/components/libc/compilers/newlib/README.md b/components/libc/compilers/newlib/README.md
new file mode 100644
index 0000000000..385f329a4f
--- /dev/null
+++ b/components/libc/compilers/newlib/README.md
@@ -0,0 +1,9 @@
+# NEWLIB (GCC) porting for RT-Thread
+
+Please define RT_USING_LIBC and compile RT-Thread with GCC compiler.
+
+
+
+## More Information
+
+https://sourceware.org/newlib/libc.html#Reentrancy
\ No newline at end of file
diff --git a/components/libc/compilers/newlib/libc.h b/components/libc/compilers/newlib/libc.h
index ab9334fe26..fdf2ab4f60 100644
--- a/components/libc/compilers/newlib/libc.h
+++ b/components/libc/compilers/newlib/libc.h
@@ -27,13 +27,19 @@
 #define MICROSECOND_PER_TICK    (MICROSECOND_PER_SECOND / RT_TICK_PER_SECOND)
 #define NANOSECOND_PER_TICK     (NANOSECOND_PER_SECOND  / RT_TICK_PER_SECOND)
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 int libc_system_init(void);
 int libc_stdio_set_console(const char* device_name, int mode);
 int libc_stdio_get_console(void);
 
 /* some time related function */
-int libc_set_time(const struct timespec *time);
-int libc_get_time(struct timespec *time);
-int libc_time_to_tick(const struct timespec *time);
+int libc_set_time(const struct timespec* time);
+int libc_get_time(struct timespec* time);
+int libc_time_to_tick(const struct timespec* time);
+#ifdef __cplusplus
+}
+#endif
 
 #endif
diff --git a/components/libc/compilers/newlib/syscalls.c b/components/libc/compilers/newlib/syscalls.c
index e4cda478cb..228fa0d140 100644
--- a/components/libc/compilers/newlib/syscalls.c
+++ b/components/libc/compilers/newlib/syscalls.c
@@ -9,22 +9,28 @@
 #include <reent.h>
 #include <sys/errno.h>
 #include <sys/time.h>
+#include <stdio.h>
+
 #include <rtthread.h>
 
 #ifdef RT_USING_DFS
 #include <dfs_posix.h>
 #endif
 
-#ifdef RT_USING_PTHREADS
-#include <pthread.h>
-#endif
-
 #ifdef RT_USING_MODULE
 #include <dlmodule.h>
 #endif
 
 /* Reentrant versions of system calls.  */
 
+#ifndef _REENT_ONLY
+int *
+__errno ()
+{
+  return _rt_errno();
+}
+#endif
+
 int
 _close_r(struct _reent *ptr, int fd)
 {
@@ -218,7 +224,7 @@ _ssize_t
 _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)
 {
 #ifndef RT_USING_DFS
-    if (fd == 0)
+    if (fileno(stdout) == fd)
     {
         rt_device_t console;
 
@@ -432,3 +438,18 @@ void abort(void)
 
     while (1);
 }
+
+uid_t getuid(void)
+{
+    return 0;
+}
+
+mode_t umask(mode_t mask)
+{
+    return 022;
+}
+
+int flock(int fd, int operation)
+{
+    return 0;
+}
diff --git a/components/libc/compilers/newlib/time.c b/components/libc/compilers/newlib/time.c
deleted file mode 100644
index 29c5c6cdd2..0000000000
--- a/components/libc/compilers/newlib/time.c
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Copyright (c) 2006-2018, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- */
-#include <sys/time.h>
-#include <rtthread.h>
-
-#ifdef RT_USING_DEVICE
-int gettimeofday(struct timeval *tp, void *ignore)
-{
-    time_t time;
-    rt_device_t device;
-
-    device = rt_device_find("rtc");
-    if (device != RT_NULL)
-    {
-        rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
-        if (tp != RT_NULL)
-        {
-            tp->tv_sec = time;
-            tp->tv_usec = 0;
-        }
-
-        return time;
-    }
-
-    return 0;
-}
-#endif
-
-/**
- * Returns the current time.
- *
- * @param time_t * t the timestamp pointer, if not used, keep NULL.
- *
- * @return time_t return timestamp current.
- *
- */
-/* for IAR 6.2 later Compiler */
-#if defined (__IAR_SYSTEMS_ICC__) &&  (__VER__) >= 6020000
-#pragma module_name = "?time"
-time_t (__time32)(time_t *t) /* Only supports 32-bit timestamp */
-#else
-time_t time(time_t *t)
-#endif
-{
-    time_t time_now = 0;
-
-#ifdef RT_USING_RTC
-    static rt_device_t device = RT_NULL;
-
-    /* optimization: find rtc device only first. */
-    if (device == RT_NULL)
-    {
-        device = rt_device_find("rtc");
-    }
-
-    /* read timestamp from RTC device. */
-    if (device != RT_NULL)
-    {
-        if (rt_device_open(device, 0) == RT_EOK)
-        {
-            rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time_now);
-            rt_device_close(device);
-        }
-    }
-#endif /* RT_USING_RTC */
-
-    /* if t is not NULL, write timestamp to *t */
-    if (t != RT_NULL)
-    {
-        *t = time_now;
-    }
-
-    return time_now;
-}
-
-RT_WEAK clock_t clock(void)
-{
-    return rt_tick_get();
-}