Merge branch 'master' of https://github.com/RT-Thread/rt-thread into nuvoton

57 files changed, 1138 insertions, 1223 deletions

diff --git a/components/libc/compilers/armlibc/SConscript b/components/libc/compilers/armlibc/SConscript
index 52f7a6d93a..bf1a299304 100644
--- a/components/libc/compilers/armlibc/SConscript
+++ b/components/libc/compilers/armlibc/SConscript
@@ -1,21 +1,12 @@
 from building import *
 Import('rtconfig')
 
-src   = Glob('*.c') + Glob('*.cpp')
-cwd   = GetCurrentDir()
+src   = Glob('*.c')
 group = []
 
-CPPPATH = [cwd]
 CPPDEFINES = ['RT_USING_ARM_LIBC']
 
-if GetDepend('RT_USING_DFS') == False:
-    SrcRemove(src, ['stdio.c'])
-
-if GetDepend('RT_USING_MODULE') == False:
-    SrcRemove(src, ['libc_syms.c'])
-
 if rtconfig.PLATFORM == 'armcc' or rtconfig.PLATFORM == 'armclang':
-    group = DefineGroup('libc', src, depend = ['RT_USING_LIBC'], 
-        CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
+    group = DefineGroup('libc', src, depend = ['RT_USING_LIBC'], CPPDEFINES = CPPDEFINES)
 
 Return('group')
diff --git a/components/libc/compilers/armlibc/libc.c b/components/libc/compilers/armlibc/libc.c
deleted file mode 100644
index 971ddb8d49..0000000000
--- a/components/libc/compilers/armlibc/libc.c
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      the first version
- */
-#include <stdio.h>
-#include <stdlib.h>
-
-#include <rtthread.h>
-
-#include "libc.h"
-
-#ifdef RT_USING_PTHREADS
-#include <pthread.h>
-#endif
-
-int libc_system_init(void)
-{
-#if defined(RT_USING_DFS) & defined(RT_USING_DFS_DEVFS)
-    rt_device_t dev_console;
-
-    dev_console = rt_console_get_device();
-    if (dev_console)
-    {
-    #if defined(RT_USING_POSIX)
-        libc_stdio_set_console(dev_console->parent.name, O_RDWR);
-    #else
-        libc_stdio_set_console(dev_console->parent.name, O_WRONLY);
-    #endif
-    }
-#endif
-
-#if defined RT_USING_PTHREADS && !defined RT_USING_COMPONENTS_INIT
-    pthread_system_init();
-#endif
-
-    return 0;
-}
-INIT_COMPONENT_EXPORT(libc_system_init);
diff --git a/components/libc/compilers/armlibc/libc.h b/components/libc/compilers/armlibc/libc.h
deleted file mode 100644
index aecf8cdc50..0000000000
--- a/components/libc/compilers/armlibc/libc.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      the first version
- */
-#ifndef __RTT_LIBC_H__
-#define __RTT_LIBC_H__
-
-#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);
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/components/libc/compilers/armlibc/mem_std.c b/components/libc/compilers/armlibc/mem_std.c
index c350aa68fa..fbfd17eee1 100644
--- a/components/libc/compilers/armlibc/mem_std.c
+++ b/components/libc/compilers/armlibc/mem_std.c
@@ -7,7 +7,8 @@
  * 2014-08-03     bernard      Add file header.
  */
 
-#include "rtthread.h"
+#include <rtthread.h>
+#include <stddef.h>
 
 #ifdef RT_USING_HEAP
 
diff --git a/components/libc/compilers/armlibc/stdio.c b/components/libc/compilers/armlibc/stdio.c
deleted file mode 100644
index c786c78aa5..0000000000
--- a/components/libc/compilers/armlibc/stdio.c
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      implement stdio for armcc.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <rtthread.h>
-#include "libc.h"
-
-#if defined(RT_USING_DFS) && defined(RT_USING_DFS_DEVFS)
-#include <dfs_posix.h>
-
-#define STDIO_DEVICE_NAME_MAX   32
-
-static int std_fd = -1;
-int libc_stdio_set_console(const char* device_name, int mode)
-{
-    int fd;
-    char name[STDIO_DEVICE_NAME_MAX];
-
-    snprintf(name, sizeof(name) - 1, "/dev/%s", device_name);
-    name[STDIO_DEVICE_NAME_MAX - 1] = '\0';
-
-    fd = open(name, mode, 0);
-    if (fd >= 0)
-    {
-        if (std_fd >= 0)
-        {
-            close(std_fd);
-        }
-        std_fd = fd;
-    }
-
-    return std_fd;
-}
-
-int libc_stdio_get_console(void)
-{
-    return std_fd;
-}
-
-int libc_stdio_read(void *buffer, size_t size)
-{
-    if (std_fd >= 0)
-    {
-        return read(std_fd, buffer, size);
-    }
-    else
-    {
-        rt_kprintf("Illegal stdio input!\n");
-        return 0;
-    }
-}
-
-int libc_stdio_write(const void *buffer, size_t size)
-{
-    if (std_fd >= 0)
-    {
-        return write(std_fd, buffer, size);
-    }
-    else
-    {
-        rt_kprintf("Illegal stdio output!\n");
-        return size;
-    }
-}
-#endif
diff --git a/components/libc/compilers/armlibc/syscalls.c b/components/libc/compilers/armlibc/syscalls.c
index ce4c358993..755ffef1a6 100644
--- a/components/libc/compilers/armlibc/syscalls.c
+++ b/components/libc/compilers/armlibc/syscalls.c
@@ -15,16 +15,20 @@
  * 2020-02-14     Meco Man     implement _sys_tmpnam()
  */
 
-#include <string.h>
 #include <rt_sys.h>
-
 #include <rtthread.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#ifdef RT_USING_POSIX
 #include "libc.h"
-
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
 #endif
 
+#define DBG_TAG    "armlibc.syscalls"
+#define DBG_LVL    DBG_INFO
+#include <rtdbg.h>
+
 #ifdef __CLANG_ARM
 __asm(".global __use_no_semihosting\n\t");
 #else
@@ -51,7 +55,7 @@ const char __stderr_name[] = "STDERR";
  */
 FILEHANDLE _sys_open(const char *name, int openmode)
 {
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     int fd;
     int mode = O_RDONLY;
 #endif
@@ -64,8 +68,8 @@ FILEHANDLE _sys_open(const char *name, int openmode)
     if (strcmp(name, __stderr_name) == 0)
         return (STDERR);
 
-#ifndef RT_USING_DFS
-    return -1;
+#ifndef RT_USING_POSIX
+    return 0; /* error */
 #else
     /* Correct openmode from fopen to open */
     if (openmode & OPEN_PLUS)
@@ -95,21 +99,22 @@ FILEHANDLE _sys_open(const char *name, int openmode)
 
     fd = open(name, mode, 0);
     if (fd < 0)
-        return -1;
+        return 0; /* error */
     else
         return fd;
-#endif
+#endif /* RT_USING_POSIX */
 }
 
 int _sys_close(FILEHANDLE fh)
 {
-#ifndef RT_USING_DFS
-    return 0;
-#else
-    if (fh <= STDERR) return 0;
+#ifdef RT_USING_POSIX
+    if (fh <= STDERR)
+        return 0; /* error */
 
     return close(fh);
-#endif
+#else
+    return 0;
+#endif /* RT_USING_POSIX */
 }
 
 /*
@@ -139,33 +144,32 @@ int _sys_close(FILEHANDLE fh)
  */
 int _sys_read(FILEHANDLE fh, unsigned char *buf, unsigned len, int mode)
 {
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     int size;
-#endif
 
     if (fh == STDIN)
     {
-#ifdef RT_USING_POSIX
-        size = libc_stdio_read(buf, len);
+        if (libc_stdio_get_console() < 0)
+        {
+            LOG_W("Do not invoke standard output before initializing libc");
+            return 0;
+        }
+        size = read(STDIN_FILENO, buf, len);
         return len - size;
-#else
-        /* no stdin */
-        return -1;
-#endif
+    }
+    else if ((fh == STDOUT) || (fh == STDERR))
+    {
+        return 0; /* error */
     }
 
-    if ((fh == STDOUT) || (fh == STDERR))
-        return -1;
-
-#ifndef RT_USING_DFS
-    return 0;
-#else
     size = read(fh, buf, len);
     if (size >= 0)
         return len - size;
     else
-        return -1;
-#endif
+        return 0; /* error */
+#else
+    return 0; /* error */
+#endif /* RT_USING_POSIX */
 }
 
 /*
@@ -175,41 +179,43 @@ int _sys_read(FILEHANDLE fh, unsigned char *buf, unsigned len, int mode)
  */
 int _sys_write(FILEHANDLE fh, const unsigned char *buf, unsigned len, int mode)
 {
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     int size;
-#endif
+#endif /* RT_USING_POSIX */
 
     if ((fh == STDOUT) || (fh == STDERR))
     {
-#if !defined(RT_USING_CONSOLE) || !defined(RT_USING_DEVICE)
-        return 0;
-#else
 #ifdef RT_USING_POSIX
-        size = libc_stdio_write(buf, len);
+        if (libc_stdio_get_console() < 0)
+        {
+            LOG_W("Do not invoke standard input before initializing libc");
+            return 0;
+        }
+        size = write(STDOUT_FILENO, buf, len);
         return len - size;
-#else
+#elif defined(RT_USING_CONSOLE)
         if (rt_console_get_device())
         {
             rt_device_write(rt_console_get_device(), -1, buf, len);
-            return 0;
         }
 
-        return -1;
-#endif
-#endif
+        return 0; /* error */
+#endif /* RT_USING_POSIX */
+    }
+    else if (fh == STDIN)
+    {
+        return 0; /* error */
     }
 
-    if (fh == STDIN) return -1;
-
-#ifndef RT_USING_DFS
-    return 0;
-#else
+#ifdef RT_USING_POSIX
     size = write(fh, buf, len);
     if (size >= 0)
         return len - size;
     else
-        return -1;
-#endif
+        return 0; /* error */
+#else
+    return 0;
+#endif /* RT_USING_POSIX */
 }
 
 /*
@@ -218,16 +224,15 @@ int _sys_write(FILEHANDLE fh, const unsigned char *buf, unsigned len, int mode)
  */
 int _sys_seek(FILEHANDLE fh, long pos)
 {
+#ifdef RT_USING_POSIX
     if (fh < STDERR)
-        return -1;
-
-#ifndef RT_USING_DFS
-    return -1;
-#else
+        return 0; /* error */
 
     /* position is relative to the start of file fh */
     return lseek(fh, pos, 0);
-#endif
+#else
+    return 0; /* error */
+#endif /* RT_USING_POSIX */
 }
 
 /**
@@ -253,7 +258,7 @@ void _ttywrch(int ch)
 
     c = (char)ch;
     rt_kprintf(&c);
-#endif
+#endif /* RT_USING_CONSOLE */
 }
 
 /* for exit() and abort() */
@@ -272,17 +277,17 @@ RT_WEAK void _sys_exit(int return_code)
  */
 long _sys_flen(FILEHANDLE fh)
 {
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     struct stat stat;
 
     if (fh < STDERR)
-        return -1;
+        return 0; /* error */
 
     fstat(fh, &stat);
     return stat.st_size;
 #else
-    return -1;
-#endif
+    return 0;
+#endif /* RT_USING_POSIX */
 }
 
 int _sys_istty(FILEHANDLE fh)
@@ -295,33 +300,27 @@ int _sys_istty(FILEHANDLE fh)
 
 int remove(const char *filename)
 {
-#ifndef RT_USING_DFS
-    return -1;
-#else
+#ifdef RT_USING_POSIX
     return unlink(filename);
-#endif
-}
-
-#if defined(RT_USING_FINSH) && defined(FINSH_USING_MSH) && defined(RT_USING_MODULE) && defined(RT_USING_DFS)
-/* use system(const char *string) implementation in the msh */
 #else
-int system(const char *string)
-{
-    extern int __rt_libc_system(const char *string);
-    return __rt_libc_system(string);
+    return 0; /* error */
+#endif /* RT_USING_POSIX */
 }
-#endif
 
 #ifdef __MICROLIB
 #include <stdio.h>
 
 int fputc(int c, FILE *f)
 {
+#ifdef RT_USING_CONSOLE
     char ch[2] = {0};
 
     ch[0] = c;
     rt_kprintf(&ch[0]);
     return 1;
+#else
+    return 0; /* error */
+#endif /* RT_USING_CONSOLE */
 }
 
 int fgetc(FILE *f)
@@ -329,10 +328,16 @@ int fgetc(FILE *f)
 #ifdef RT_USING_POSIX
     char ch;
 
-    if (libc_stdio_read(&ch, 1) == 1)
-        return ch;
-#endif
+    if (libc_stdio_get_console() < 0)
+    {
+        LOG_W("Do not invoke standard output before initializing libc");
+        return 0;
+    }
 
-    return -1;
+    if(read(STDIN_FILENO, &ch, 1) == 1)
+        return ch;
+#endif /* RT_USING_POSIX */
+    return 0; /* error */
 }
-#endif
+
+#endif /* __MICROLIB */
diff --git a/components/libc/compilers/common/SConscript b/components/libc/compilers/common/SConscript
index b1982aa329..504bf84e56 100644
--- a/components/libc/compilers/common/SConscript
+++ b/components/libc/compilers/common/SConscript
@@ -1,30 +1,25 @@
 from building import *
-
 Import('rtconfig')
 
 src   = []
 cwd   = GetCurrentDir()
 group = []
 CPPPATH = [cwd]
+CPPDEFINES = []
+
+if rtconfig.CROSS_TOOL == 'keil':
+    CPPDEFINES += ['__CLK_TCK=RT_TICK_PER_SECOND']
 
 if GetDepend('RT_USING_LIBC'):
     src += Glob('*.c')
-    if GetDepend('RT_USING_POSIX') == False:
-        SrcRemove(src, ['unistd.c', 'delay.c'])
 elif GetDepend('RT_LIBC_USING_TIME'):
     src += ['time.c']
 
-if rtconfig.CROSS_TOOL == 'keil':
-    CPPDEFINES = ['__CLK_TCK=RT_TICK_PER_SECOND']
-else:
-    CPPDEFINES = []
-
 group = DefineGroup('libc', src, depend = [], CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
 
 list = os.listdir(cwd)
-for d in list:
-    path = os.path.join(cwd, d)
-    if os.path.isfile(os.path.join(path, 'SConscript')):
-        group = group + SConscript(os.path.join(d, 'SConscript'))
+for item in list:
+    if os.path.isfile(os.path.join(cwd, item, 'SConscript')):
+        group = group + SConscript(os.path.join(item, 'SConscript'))
 
 Return('group')
diff --git a/components/libc/compilers/common/delay.c b/components/libc/compilers/common/delay.c
deleted file mode 100644
index 4666258d3b..0000000000
--- a/components/libc/compilers/common/delay.c
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2021-05-07     Meco Man     first Version
- */
-#include <rtthread.h>
-#include <rthw.h>
-
-void msleep(unsigned int msecs)
-{
-    rt_thread_mdelay(msecs);
-}
-RTM_EXPORT(msleep);
-
-void ssleep(unsigned int seconds)
-{
-    msleep(seconds * 1000);
-}
-RTM_EXPORT(ssleep);
-
-void mdelay(unsigned long msecs)
-{
-    rt_hw_us_delay(msecs * 1000);
-}
-RTM_EXPORT(mdelay);
-
-void udelay(unsigned long usecs)
-{
-    rt_hw_us_delay(usecs);
-}
-RTM_EXPORT(udelay);
-
-void ndelay(unsigned long nsecs)
-{
-    rt_hw_us_delay(1);
-}
-RTM_EXPORT(ndelay);
diff --git a/components/libc/compilers/common/dirent.h b/components/libc/compilers/common/dirent.h
index bfba586093..a6353fd6f8 100644
--- a/components/libc/compilers/common/dirent.h
+++ b/components/libc/compilers/common/dirent.h
@@ -6,10 +6,14 @@
  * Change Logs:
  * Date           Author       Notes
  */
-#ifndef __RTT_DIRENT_H__
-#define __RTT_DIRENT_H__
+#ifndef __DIRENT_H__
+#define __DIRENT_H__
 
-#include <rtthread.h>
+#include <rtdef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /*
 * dirent.h - format of directory entries
@@ -26,27 +30,28 @@
 #define DT_REG          0x01
 #define DT_DIR          0x02
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #ifndef HAVE_DIR_STRUCTURE
+#define HAVE_DIR_STRUCTURE
 typedef struct
 {
     int fd;                         /* directory file */
     char buf[512];
     int num;
     int cur;
-} DIR;
+}DIR;
 #endif
 
 #ifndef HAVE_DIRENT_STRUCTURE
+#define HAVE_DIRENT_STRUCTURE
+
+#define DIRENT_NAME_MAX    256
+
 struct dirent
 {
     rt_uint8_t  d_type;             /* The type of the file */
     rt_uint8_t  d_namlen;           /* The length of the not including the terminating null file name */
     rt_uint16_t d_reclen;           /* length of this record */
-    char d_name[256];               /* The null-terminated file name */
+    char d_name[DIRENT_NAME_MAX];   /* The null-terminated file name */
 };
 #endif
 
diff --git a/components/libc/compilers/common/fcntl.h b/components/libc/compilers/common/fcntl.h
new file mode 100644
index 0000000000..3460926708
--- /dev/null
+++ b/components/libc/compilers/common/fcntl.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2021-09-02     Meco Man     First version
+ */
+#ifndef __FCNTL_H__
+#define __FCNTL_H__
+
+#include <sys/types.h>
+
+#define O_RDONLY    0x0000      /* open for reading only */
+#define O_WRONLY    0x0001      /* open for writing only */
+#define O_RDWR      0x0002      /* open for reading and writing */
+#define O_ACCMODE   0x0003      /* mask for above modes */
+
+#define O_CREAT        0100
+#define O_EXCL         0200
+#define O_NOCTTY       0400
+#define O_TRUNC       01000
+#define O_APPEND      02000
+#define O_NONBLOCK    04000
+#define O_DSYNC      010000
+#define O_SYNC     04010000
+#define O_RSYNC    04010000
+#define O_BINARY    0100000
+#define O_DIRECTORY 0200000
+#define O_NOFOLLOW  0400000
+#define O_CLOEXEC  02000000
+#define O_ASYNC      020000
+#define O_DIRECT     040000
+#define O_LARGEFILE 0100000
+#define O_NOATIME  01000000
+#define O_PATH    010000000
+#define O_TMPFILE 020200000
+#define O_NDELAY O_NONBLOCK
+#define O_SEARCH  O_PATH
+#define O_EXEC    O_PATH
+
+#define F_DUPFD  0
+#define F_GETFD  1
+#define F_SETFD  2
+#define F_GETFL  3
+#define F_SETFL  4
+
+#define F_SETOWN 8
+#define F_GETOWN 9
+#define F_SETSIG 10
+#define F_GETSIG 11
+
+#define F_GETLK 12
+#define F_SETLK 13
+#define F_SETLKW 14
+
+#define F_SETOWN_EX 15
+#define F_GETOWN_EX 16
+
+#define F_GETOWNER_UIDS 17
+
+int open(const char *file, int flags, ...);
+int fcntl(int fildes, int cmd, ...);
+int creat(const char *, mode_t);
+
+#endif
diff --git a/components/libc/compilers/common/none-gcc/SConscript b/components/libc/compilers/common/nogcc/SConscript
index c766c8f82d..c766c8f82d 100644
--- a/components/libc/compilers/common/none-gcc/SConscript
+++ b/components/libc/compilers/common/nogcc/SConscript
diff --git a/components/libc/compilers/common/none-gcc/readme.md b/components/libc/compilers/common/nogcc/readme.md
index b10940d003..b10940d003 100644
--- a/components/libc/compilers/common/none-gcc/readme.md
+++ b/components/libc/compilers/common/nogcc/readme.md
diff --git a/components/libc/compilers/common/none-gcc/sys/errno.h b/components/libc/compilers/common/nogcc/sys/errno.h
index ad3614024d..ff1abca387 100644
--- a/components/libc/compilers/common/none-gcc/sys/errno.h
+++ b/components/libc/compilers/common/nogcc/sys/errno.h
@@ -7,8 +7,8 @@
  * Date           Author       Notes
  * 2021-05-22     Meco Man     The first version.
  */
-#ifndef _SYS_ERRNO_H
-#define _SYS_ERRNO_H
+#ifndef __SYS_ERRNO_H__
+#define __SYS_ERRNO_H__
 
 #if defined(__ARMCC_VERSION)
 /*
diff --git a/components/libc/compilers/common/nogcc/sys/select.h b/components/libc/compilers/common/nogcc/sys/select.h
new file mode 100644
index 0000000000..02fb77dd89
--- /dev/null
+++ b/components/libc/compilers/common/nogcc/sys/select.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2021-07-21     Meco Man     The first version
+ */
+
+#ifndef __SYS_SELECT_H__
+#define __SYS_SELECT_H__
+
+#include <rtconfig.h>
+#include <sys/types.h>
+#include <sys/time.h>
+
+#ifdef _WIN32
+#include <winsock.h>
+#endif
+
+#ifndef  FD_SETSIZE
+#define  FD_SETSIZE  32
+#endif
+
+#ifdef SAL_USING_POSIX
+#ifdef FD_SETSIZE
+#undef FD_SETSIZE
+#endif
+#define FD_SETSIZE      DFS_FD_MAX
+#endif /* SAL_USING_POSIX */
+
+typedef long    fd_mask;
+
+#ifndef _WIN32
+#ifndef _SYS_TYPES_FD_SET /* MIPS */
+
+#define   NBBY    8       /* number of bits in a byte */
+#define   NFDBITS (sizeof (fd_mask) * NBBY)   /* bits per mask */
+#ifndef   howmany
+#define   howmany(x,y)    (((x)+((y)-1))/(y))
+#endif
+
+typedef struct _types_fd_set {
+    fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
+} _types_fd_set;
+#define fd_set _types_fd_set
+
+#define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1L << ((n) % NFDBITS)))
+#define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1L << ((n) % NFDBITS)))
+#define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1L << ((n) % NFDBITS)))
+#define FD_ZERO(p)      memset((void*)(p), 0, sizeof(*(p)))
+#endif /* _SYS_TYPES_FD_SET */
+
+int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout);
+#endif /* _WIN32 */
+
+#endif /* __SYS_SELECT_H__ */
diff --git a/components/libc/compilers/common/nogcc/sys/stat.h b/components/libc/compilers/common/nogcc/sys/stat.h
new file mode 100644
index 0000000000..107c15decf
--- /dev/null
+++ b/components/libc/compilers/common/nogcc/sys/stat.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2021-09-02     Meco Man     First version
+ */
+
+#ifndef __SYS_STAT_H__
+#define __SYS_STAT_H__
+
+#include <sys/types.h>
+#include <sys/time.h>
+
+#define S_IFMT               00170000
+#define S_IFSOCK             0140000
+#define S_IFLNK              0120000
+#define S_IFREG              0100000
+#define S_IFBLK              0060000
+#define S_IFDIR              0040000
+#define S_IFCHR              0020000
+#define S_IFIFO              0010000
+#define S_ISUID              0004000
+#define S_ISGID              0002000
+#define S_ISVTX              0001000
+
+#define S_ISLNK(m)           (((m) & S_IFMT) == S_IFLNK)
+#define S_ISREG(m)           (((m) & S_IFMT) == S_IFREG)
+#define S_ISDIR(m)           (((m) & S_IFMT) == S_IFDIR)
+#define S_ISCHR(m)           (((m) & S_IFMT) == S_IFCHR)
+#define S_ISBLK(m)           (((m) & S_IFMT) == S_IFBLK)
+#define S_ISFIFO(m)          (((m) & S_IFMT) == S_IFIFO)
+#define S_ISSOCK(m)          (((m) & S_IFMT) == S_IFSOCK)
+
+#define S_IRWXU              00700
+#define S_IRUSR              00400
+#define S_IWUSR              00200
+#define S_IXUSR              00100
+
+#define S_IRWXG              00070
+#define S_IRGRP              00040
+#define S_IWGRP              00020
+#define S_IXGRP              00010
+
+#define S_IRWXO              00007
+#define S_IROTH              00004
+#define S_IWOTH              00002
+#define S_IXOTH              00001
+
+struct stat
+{
+    struct rt_device *st_dev;
+    uint16_t  st_ino;
+    uint16_t  st_mode;
+    uint16_t  st_nlink;
+    uint16_t  st_uid;
+    uint16_t  st_gid;
+    struct rt_device *st_rdev;
+    uint32_t  st_size;
+    time_t    st_atime;
+    long      st_spare1;
+    time_t    st_mtime;
+    long      st_spare2;
+    time_t    st_ctime;
+    long      st_spare3;
+    uint32_t  st_blksize;
+    uint32_t  st_blocks;
+    long      st_spare4[2];
+};
+
+int    chmod(const char *, mode_t);
+int    fchmod(int, mode_t);
+int    fstat(int, struct stat *);
+int    lstat(const char *, struct stat *);
+int    mkdir(const char *, mode_t);
+int    mkfifo(const char *, mode_t);
+int    mknod(const char *, mode_t, dev_t);
+int    stat(const char *, struct stat *);
+mode_t umask(mode_t);
+
+#endif
diff --git a/components/libc/compilers/common/none-gcc/sys/types.h b/components/libc/compilers/common/nogcc/sys/types.h
index 7222326a2a..5672f54a4d 100644
--- a/components/libc/compilers/common/none-gcc/sys/types.h
+++ b/components/libc/compilers/common/nogcc/sys/types.h
@@ -8,10 +8,12 @@
  * 2020-09-05     Meco Man     fix bugs
  * 2020-12-16     Meco Man     add useconds_t
  */
-#ifndef __TYPES_H__
-#define __TYPES_H__
+#ifndef __SYS_TYPES_H__
+#define __SYS_TYPES_H__
 
 #include <stdint.h>
+#include <stddef.h>
+#include <time.h>
 
 typedef int32_t          clockid_t;
 typedef int32_t          key_t;         /* Used for interprocess communication. */
@@ -25,6 +27,7 @@ typedef signed int       ssize_t;       /* Used for a count of bytes or an error
 #else
 typedef long signed int  ssize_t;       /* Used for a count of bytes or an error indication. */
 #endif
+typedef long             suseconds_t;   /* microseconds. */
 typedef unsigned long    useconds_t;    /* microseconds (unsigned) */
 
 typedef unsigned long    dev_t;
diff --git a/components/libc/compilers/common/nogcc/sys/unistd.h b/components/libc/compilers/common/nogcc/sys/unistd.h
new file mode 100644
index 0000000000..6195c4c2aa
--- /dev/null
+++ b/components/libc/compilers/common/nogcc/sys/unistd.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2020-12-16     Meco Man     add usleep
+ * 2021-09-11     Meco Man     move functions from dfs_posix.h to unistd.h
+ */
+#ifndef __SYS_UNISTD_H__
+#define __SYS_UNISTD_H__
+
+#include <stddef.h>
+#include "types.h" /* <sys/types.h> */
+
+#define STDIN_FILENO    0       /* standard input file descriptor */
+#define STDOUT_FILENO   1       /* standard output file descriptor */
+#define STDERR_FILENO   2       /* standard error file descriptor */
+
+ssize_t read(int fd, void *buf, size_t len);
+ssize_t write(int fd, const void *buf, size_t len);
+off_t lseek(int fd, off_t offset, int whence);
+int fsync(int fildes);
+int unlink(const char *pathname);
+int close(int d);
+int ftruncate(int fd, off_t length);
+int rmdir(const char *path);
+int chdir(const char *path);
+char *getcwd(char *buf, size_t size);
+int access(const char *path, int amode);
+int pipe(int fildes[2]);
+int isatty(int fd);
+char *ttyname(int desc);
+unsigned int sleep(unsigned int seconds);
+int usleep(useconds_t usec);
+pid_t gettid(void);
+pid_t getpid(void);
+pid_t getppid(void);
+uid_t getuid(void);
+uid_t geteuid(void);
+gid_t getgid(void);
+gid_t getegid(void);
+
+#endif /* _SYS_UNISTD_H */
diff --git a/components/libc/compilers/common/none-gcc/unistd.h b/components/libc/compilers/common/nogcc/unistd.h
index cd77a12e3b..cd77a12e3b 100644
--- a/components/libc/compilers/common/none-gcc/unistd.h
+++ b/components/libc/compilers/common/nogcc/unistd.h
diff --git a/components/libc/compilers/common/none-gcc/sys/stat.h b/components/libc/compilers/common/none-gcc/sys/stat.h
deleted file mode 100644
index c4b42083c4..0000000000
--- a/components/libc/compilers/common/none-gcc/sys/stat.h
+++ /dev/null
@@ -1,8 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- */
diff --git a/components/libc/compilers/common/none-gcc/sys/unistd.h b/components/libc/compilers/common/none-gcc/sys/unistd.h
deleted file mode 100644
index 2f01f660b3..0000000000
--- a/components/libc/compilers/common/none-gcc/sys/unistd.h
+++ /dev/null
@@ -1,81 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2020-12-16     Meco Man     add usleep
- */
-#ifndef _SYS_UNISTD_H
-#define _SYS_UNISTD_H
-
-#include <rtconfig.h>
-#include "types.h"
-
-#ifdef RT_USING_DFS
-
-#define STDIN_FILENO    0       /* standard input file descriptor */
-#define STDOUT_FILENO   1       /* standard output file descriptor */
-#define STDERR_FILENO   2       /* standard error file descriptor */
-
-#include <dfs_posix.h>
-#else
-#define _FREAD      0x0001  /* read enabled */
-#define _FWRITE     0x0002  /* write enabled */
-#define _FAPPEND    0x0008  /* append (writes guaranteed at the end) */
-#define _FMARK      0x0010  /* internal; mark during gc() */
-#define _FDEFER     0x0020  /* internal; defer for next gc pass */
-#define _FASYNC     0x0040  /* signal pgrp when data ready */
-#define _FSHLOCK    0x0080  /* BSD flock() shared lock present */
-#define _FEXLOCK    0x0100  /* BSD flock() exclusive lock present */
-#define _FCREAT     0x0200  /* open with file create */
-#define _FTRUNC     0x0400  /* open with truncation */
-#define _FEXCL      0x0800  /* error on open if file exists */
-#define _FNBIO      0x1000  /* non blocking I/O (sys5 style) */
-#define _FSYNC      0x2000  /* do all writes synchronously */
-#define _FNONBLOCK  0x4000  /* non blocking I/O (POSIX style) */
-#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);
-unsigned int sleep(unsigned int seconds);
-int usleep(useconds_t usec);
-pid_t gettid(void);
-pid_t getpid(void);
-pid_t getppid(void);
-uid_t getuid(void);
-uid_t geteuid(void);
-gid_t getgid(void);
-gid_t getegid(void);
-
-#endif /* _SYS_UNISTD_H */
diff --git a/components/libc/compilers/common/poll.h b/components/libc/compilers/common/poll.h
new file mode 100644
index 0000000000..aea73d6eaf
--- /dev/null
+++ b/components/libc/compilers/common/poll.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2021-09-11     Meco Man     First version
+ */
+#ifndef __POLL_H__
+#define __POLL_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if !defined(POLLIN) && !defined(POLLOUT)
+#define POLLIN          (0x01)
+#define POLLRDNORM      (0x01)
+#define POLLRDBAND      (0x01)
+#define POLLPRI         (0x01)
+
+#define POLLOUT         (0x02)
+#define POLLWRNORM      (0x02)
+#define POLLWRBAND      (0x02)
+
+#define POLLERR         (0x04)
+#define POLLHUP         (0x08)
+#define POLLNVAL        (0x10)
+
+typedef unsigned int nfds_t;
+
+struct pollfd
+{
+    int fd;
+    short events;
+    short revents;
+};
+#endif /* !defined(POLLIN) && !defined(POLLOUT) */
+
+#define POLLMASK_DEFAULT (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
+
+int poll(struct pollfd *fds, nfds_t nfds, int timeout);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __POLL_H__ */
diff --git a/components/libc/compilers/common/readme.md b/components/libc/compilers/common/readme.md
index 856ddeb045..82e23f8970 100644
--- a/components/libc/compilers/common/readme.md
+++ b/components/libc/compilers/common/readme.md
@@ -1,10 +1 @@
-## Attentions
-
-1. This folder is "common" for all toolchains.
-
-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
+This folder is "common" for all toolchains.
\ No newline at end of file
diff --git a/components/libc/compilers/common/stdlib.c b/components/libc/compilers/common/stdlib.c
index 9d8952e99e..6cc0b9fdac 100644
--- a/components/libc/compilers/common/stdlib.c
+++ b/components/libc/compilers/common/stdlib.c
@@ -10,19 +10,36 @@
 
 #include <rtthread.h>
 
+#define DBG_TAG    "stdlib"
+#define DBG_LVL    DBG_INFO
+#include <rtdbg.h>
+
 void __rt_libc_exit(int status)
 {
     rt_thread_t self = rt_thread_self();
 
     if (self != RT_NULL)
     {
-        rt_kprintf("thread:%s exit:%d!\n", self->name, status);
+        LOG_E("thread:%s exit:%d!", self->name, status);
         rt_thread_control(self, RT_THREAD_CTRL_CLOSE, RT_NULL);
     }
 }
 
-int __rt_libc_system(const char *string)
+#ifdef RT_USING_MSH
+int system(const char *command)
 {
-    /* TODO */
-    return 0;
+    extern int msh_exec(char *cmd, rt_size_t length);
+
+    int ret = -RT_ENOMEM;
+    char *cmd = rt_strdup(command);
+
+    if (cmd)
+    {
+        ret = msh_exec(cmd, rt_strlen(cmd));
+        rt_free(cmd);
+    }
+
+    return ret;
 }
+RTM_EXPORT(system);
+#endif
diff --git a/components/libc/compilers/common/sys/ioctl.h b/components/libc/compilers/common/sys/ioctl.h
index 51f51f2ea4..04f73837bc 100644
--- a/components/libc/compilers/common/sys/ioctl.h
+++ b/components/libc/compilers/common/sys/ioctl.h
@@ -15,6 +15,10 @@
 #include <dfs_posix.h>
 #endif
 
+#ifdef _WIN32
+#include <winsock.h>
+#endif
+
 struct winsize {
     unsigned short ws_row;
     unsigned short ws_col;
@@ -35,8 +39,8 @@ struct winsize {
 
 #define FIONREAD    _IOR('f', 127, int) /* get # bytes to read */
 #define FIONBIO     _IOW('f', 126, int) /* set/clear non-blocking i/o */
-#define FIONWRITE   _IOR('f', 121, int) /* get # bytes outstanding in send queue */
 #endif
+#define FIONWRITE   _IOR('f', 121, int) /* get # bytes outstanding in send queue */
 
 #define TCGETS      0x5401
 #define TCSETS      0x5402
@@ -235,4 +239,6 @@ struct winsize {
 #define SIOCDEVPRIVATE      0x89F0
 #define SIOCPROTOPRIVATE    0x89E0
 
+int ioctl(int fildes, int cmd, ...);
+
 #endif
diff --git a/components/libc/compilers/common/sys/signal.h b/components/libc/compilers/common/sys/signal.h
new file mode 100644
index 0000000000..9787958a37
--- /dev/null
+++ b/components/libc/compilers/common/sys/signal.h
@@ -0,0 +1,194 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2017-09-12     Bernard      The first version
+ * 2021-07-21     Meco Man     move to libc/common
+ */
+
+#ifndef __SYS_SIGNAL_H__
+#define __SYS_SIGNAL_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+/*  Signal Generation and Delivery, P1003.1b-1993, p. 63
+    NOTE: P1003.1c/D10, p. 34 adds sigev_notify_function and
+          sigev_notify_attributes to the sigevent structure.  */
+union sigval
+{
+    int    sival_int;    /* Integer signal value */
+    void  *sival_ptr;    /* Pointer signal value */
+};
+
+struct sigevent
+{
+    int          sigev_notify;               /* Notification type */
+    int          sigev_signo;                /* Signal number */
+    union sigval sigev_value;                /* Signal value */
+    void         (*sigev_notify_function)( union sigval );
+                                             /* Notification function */
+    void         *sigev_notify_attributes;   /* Notification Attributes, really pthread_attr_t */
+};
+
+struct siginfo
+{
+    uint16_t si_signo;
+    uint16_t si_code;
+
+    union sigval si_value;
+};
+typedef struct siginfo siginfo_t;
+
+#define SI_USER     0x01    /* Signal sent by kill(). */
+#define SI_QUEUE    0x02    /* Signal sent by sigqueue(). */
+#define SI_TIMER    0x03    /* Signal generated by expiration of a timer set by timer_settime(). */
+#define SI_ASYNCIO  0x04    /* Signal generated by completion of an asynchronous I/O request. */
+#define SI_MESGQ    0x05    /* Signal generated by arrival of a message on an empty message queue. */
+
+typedef void (*_sig_func_ptr)(int);
+typedef unsigned long sigset_t;
+
+struct sigaction
+{
+    _sig_func_ptr sa_handler;
+    sigset_t sa_mask;
+    int sa_flags;
+};
+
+#define SIG_SETMASK 0   /* set mask with sigprocmask() */
+#define SIG_BLOCK   1   /* set of signals to block */
+#define SIG_UNBLOCK 2   /* set of signals to, well, unblock */
+
+#define sigaddset(what,sig) (*(what) |= (1<<(sig)), 0)
+#define sigdelset(what,sig) (*(what) &= ~(1<<(sig)), 0)
+#define sigemptyset(what)   (*(what) = 0, 0)
+#define sigfillset(what)    (*(what) = ~(0), 0)
+#define sigismember(what,sig) (((*(what)) & (1<<(sig))) != 0)
+
+int sigprocmask (int how, const sigset_t *set, sigset_t *oset);
+int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact);
+
+#ifdef __ARMCC_VERSION
+#define SIGHUP       1
+/* #define SIGINT       2 */
+#define SIGQUIT      3
+/* #define SIGILL       4 */
+#define SIGTRAP      5
+/* #define SIGABRT      6 */
+#define SIGEMT       7
+/* #define SIGFPE       8 */
+#define SIGKILL      9
+#define SIGBUS      10
+/* #define SIGSEGV     11 */
+#define SIGSYS      12
+#define SIGPIPE     13
+#define SIGALRM     14
+/* #define SIGTERM     15 */
+#define SIGURG      16
+#define SIGSTOP     17
+#define SIGTSTP     18
+#define SIGCONT     19
+#define SIGCHLD     20
+#define SIGTTIN     21
+#define SIGTTOU     22
+#define SIGPOLL     23
+#define SIGWINCH    24
+/* #define SIGUSR1     25 */
+/* #define SIGUSR2     26 */
+#define SIGRTMIN    27
+#define SIGRTMAX    31
+#define NSIG        32
+
+#include <signal.h>
+
+#elif defined(__IAR_SYSTEMS_ICC__)
+#define SIGHUP       1
+#define SIGINT       2
+#define SIGQUIT      3
+#define SIGILL       4
+#define SIGTRAP      5
+/* #define SIGABRT      6 */
+#define SIGEMT       7
+#define SIGFPE       8
+#define SIGKILL      9
+#define SIGBUS      10
+#define SIGSEGV     11
+#define SIGSYS      12
+#define SIGPIPE     13
+#define SIGALRM     14
+#define SIGTERM     15
+#define SIGURG      16
+#define SIGSTOP     17
+#define SIGTSTP     18
+#define SIGCONT     19
+#define SIGCHLD     20
+#define SIGTTIN     21
+#define SIGTTOU     22
+#define SIGPOLL     23
+#define SIGWINCH    24
+#define SIGUSR1     25
+#define SIGUSR2     26
+#define SIGRTMIN    27
+#define SIGRTMAX    31
+#define NSIG        32
+
+#include <signal.h>
+
+#elif defined(__GNUC__)
+#define SIGHUP  1   /* hangup */
+#define SIGINT  2   /* interrupt */
+#define SIGQUIT 3   /* quit */
+#define SIGILL  4   /* illegal instruction (not reset when caught) */
+#define SIGTRAP 5   /* trace trap (not reset when caught) */
+#define SIGIOT  6   /* IOT instruction */
+#define SIGABRT 6   /* used by abort, replace SIGIOT in the future */
+#define SIGEMT  7   /* EMT instruction */
+#define SIGFPE  8   /* floating point exception */
+#define SIGKILL 9   /* kill (cannot be caught or ignored) */
+#define SIGBUS  10  /* bus error */
+#define SIGSEGV 11  /* segmentation violation */
+#define SIGSYS  12  /* bad argument to system call */
+#define SIGPIPE 13  /* write on a pipe with no one to read it */
+#define SIGALRM 14  /* alarm clock */
+#define SIGTERM 15  /* software termination signal from kill */
+#define SIGURG  16  /* urgent condition on IO channel */
+#define SIGSTOP 17  /* sendable stop signal not from tty */
+#define SIGTSTP 18  /* stop signal from tty */
+#define SIGCONT 19  /* continue a stopped process */
+#define SIGCHLD 20  /* to parent on child stop or exit */
+#define SIGCLD  20  /* System V name for SIGCHLD */
+#define SIGTTIN 21  /* to readers pgrp upon background tty read */
+#define SIGTTOU 22  /* like TTIN for output if (tp->t_local&LTOSTOP) */
+#define SIGIO   23  /* input/output possible signal */
+#define SIGPOLL SIGIO   /* System V name for SIGIO */
+#define SIGXCPU 24  /* exceeded CPU time limit */
+#define SIGXFSZ 25  /* exceeded file size limit */
+#define SIGVTALRM 26    /* virtual time alarm */
+#define SIGPROF 27  /* profiling time alarm */
+#define SIGWINCH 28 /* window changed */
+#define SIGLOST 29  /* resource lost (eg, record-lock lost) */
+#define SIGUSR1 30  /* user defined signal 1 */
+#define SIGUSR2 31  /* user defined signal 2 */
+#define NSIG    32      /* signal 0 implied */
+
+#ifndef _SIGNAL_H_
+/* Some applications take advantage of the fact that <sys/signal.h>
+ * and <signal.h> are equivalent in glibc.  Allow for that here.  */
+#include <signal.h>
+#endif
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
diff --git a/components/libc/compilers/common/sys/statfs.h b/components/libc/compilers/common/sys/statfs.h
index 0996af9a18..0c6dc44df3 100644
--- a/components/libc/compilers/common/sys/statfs.h
+++ b/components/libc/compilers/common/sys/statfs.h
@@ -6,16 +6,19 @@
  * Change Logs:
  * Date           Author       Notes
  */
-#ifndef __RTT_STATFS_H__
-#define __RTT_STATFS_H__
+#ifndef __SYS_STATFS_H__
+#define __SYS_STATFS_H__
 
-#include <rtthread.h>
+#include <stddef.h>
 
 struct statfs
 {
-    rt_size_t f_bsize;   /* block size */
-    rt_size_t f_blocks;  /* total data blocks in file system */
-    rt_size_t f_bfree;   /* free blocks in file system */
+    size_t f_bsize;   /* block size */
+    size_t f_blocks;  /* total data blocks in file system */
+    size_t f_bfree;   /* free blocks in file system */
 };
 
+int statfs(const char *path, struct statfs *buf);
+int fstatfs(int fd, struct statfs *buf);
+
 #endif
diff --git a/components/libc/compilers/common/sys/time.h b/components/libc/compilers/common/sys/time.h
index bb1a9c96fd..d14905ebfb 100644
--- a/components/libc/compilers/common/sys/time.h
+++ b/components/libc/compilers/common/sys/time.h
@@ -8,16 +8,19 @@
  * 2020-09-07     Meco Man     combine gcc armcc iccarm
  * 2021-02-12     Meco Man     move all definitions located in <clock_time.h> to this file
  */
-#ifndef _SYS_TIME_H_
-#define _SYS_TIME_H_
+#ifndef __SYS_TIME_H__
+#define __SYS_TIME_H__
 
 #include <rtconfig.h>
+#include <sys/types.h>
+#include <stdint.h>
 #include <time.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/* timezone */
 #define DST_NONE    0   /* not on dst */
 #define DST_USA     1   /* USA style dst */
 #define DST_AUST    2   /* Australian style dst */
@@ -30,32 +33,37 @@ extern "C" {
 #define DST_TUR     9   /* Turkey */
 #define DST_AUSTALT 10  /* Australian style with shift in 1986 */
 
-#ifndef _TIMEVAL_DEFINED
-#define _TIMEVAL_DEFINED
+struct timezone
+{
+    int tz_minuteswest;   /* minutes west of Greenwich */
+    int tz_dsttime;       /* type of dst correction */
+};
+
 /*
  * Structure returned by gettimeofday(2) system call,
  * and used in other calls.
  */
-#if !(defined(_WIN32))
-struct timeval {
-    long    tv_sec;     /* seconds */
-    long    tv_usec;    /* and microseconds */
+#ifndef _TIMEVAL_DEFINED
+#define _TIMEVAL_DEFINED
+#if !defined(_WIN32)
+struct timeval
+{
+    time_t      tv_sec;     /* seconds */
+    suseconds_t tv_usec;    /* and microseconds */
 };
 #endif
 #endif /* _TIMEVAL_DEFINED */
 
-#if !(defined(__GNUC__) && !defined(__ARMCC_VERSION)/*GCC*/) && !(defined(__ICCARM__) && (__VER__ >= 8010001)) && !defined(_WIN32)
-struct timespec {
+#if !(defined(__GNUC__) && !defined(__ARMCC_VERSION)/*GCC*/) && \
+    !(defined(__ICCARM__) && (__VER__ >= 8010001)) && \
+    !defined(_WIN32)
+struct timespec
+{
     time_t  tv_sec;     /* seconds */
     long    tv_nsec;    /* and nanoseconds */
 };
 #endif
 
-struct timezone {
-  int tz_minuteswest;   /* minutes west of Greenwich */
-  int tz_dsttime;       /* type of dst correction */
-};
-
 int stime(const time_t *t);
 time_t timegm(struct tm * const t);
 int gettimeofday(struct timeval *tv, struct timezone *tz);
@@ -65,8 +73,7 @@ struct tm *gmtime_r(const time_t *timep, struct tm *r);
 #endif
 
 #ifdef RT_USING_POSIX
-#include <sys/types.h>
-/* posix clock and timer */
+/* POSIX clock and timer */
 #define MILLISECOND_PER_SECOND  1000UL
 #define MICROSECOND_PER_SECOND  1000000UL
 #define NANOSECOND_PER_SECOND   1000000000UL
@@ -95,9 +102,13 @@ struct tm *gmtime_r(const time_t *timep, struct tm *r);
 int clock_getres  (clockid_t clockid, struct timespec *res);
 int clock_gettime (clockid_t clockid, struct timespec *tp);
 int clock_settime (clockid_t clockid, const struct timespec *tp);
-int clock_time_to_tick(const struct timespec *time);
+int rt_timespec_to_tick(const struct timespec *time);
 #endif /* RT_USING_POSIX */
 
+void tz_set(int8_t tz);
+int8_t tz_get(void);
+int8_t tz_is_dst(void);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/components/libc/compilers/common/none-gcc/fcntl.h b/components/libc/compilers/common/sys/vfs.h
index f247b926e9..00739ab1c6 100644
--- a/components/libc/compilers/common/none-gcc/fcntl.h
+++ b/components/libc/compilers/common/sys/vfs.h
@@ -5,14 +5,11 @@
  *
  * Change Logs:
  * Date           Author       Notes
+ * 2021-09-11     Meco Man     First version
  */
-#ifndef FCNTL_H__
-#define FCNTL_H__
+#ifndef __SYS_VFS_H__
+#define __SYS_VFS_H__
 
-#include <rtconfig.h>
-
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
-#endif
+#include "statfs.h" /* <sys/statfs.h> */
 
 #endif
diff --git a/components/libc/compilers/common/time.c b/components/libc/compilers/common/time.c
index e79a22b9db..5bfff15914 100644
--- a/components/libc/compilers/common/time.c
+++ b/components/libc/compilers/common/time.c
@@ -18,24 +18,21 @@
  * 2021-02-12     Meco Man     move all of the functions located in <clock_time.c> to this file
  * 2021-03-15     Meco Man     fixed a bug of leaking memory in asctime()
  * 2021-05-01     Meco Man     support fixed timezone
+ * 2021-07-21     Meco Man     implement that change/set timezone APIs
  */
 
 #include "sys/time.h"
 #include <sys/errno.h>
 #include <rtthread.h>
-
+#include <rthw.h>
 #ifdef RT_USING_DEVICE
 #include <rtdevice.h>
 #endif
 
-#define DBG_TAG    "TIME"
+#define DBG_TAG    "time"
 #define DBG_LVL    DBG_INFO
 #include <rtdbg.h>
 
-#ifndef RT_LIBC_FIXED_TIMEZONE
-#define RT_LIBC_FIXED_TIMEZONE 8 /* UTC+8 */
-#endif
-
 /* seconds per day */
 #define SPD 24*60*60
 
@@ -104,7 +101,7 @@ static rt_err_t get_timeval(struct timeval *tv)
         if (rt_device_open(device, 0) == RT_EOK)
         {
             rst = rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &tv->tv_sec);
-            rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME_US, &tv->tv_usec);
+            rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIMEVAL, tv);
             rt_device_close(device);
         }
     }
@@ -150,7 +147,7 @@ static int set_timeval(struct timeval *tv)
         if (rt_device_open(device, 0) == RT_EOK)
         {
             rst = rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &tv->tv_sec);
-            rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME_US, &tv->tv_usec);
+            rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIMEVAL, tv);
             rt_device_close(device);
         }
     }
@@ -202,7 +199,7 @@ struct tm *gmtime_r(const time_t *timep, struct tm *r)
     r->tm_mon = i;
     r->tm_mday += work - __spm[i];
 
-    r->tm_isdst = 0;
+    r->tm_isdst = tz_is_dst();
     return r;
 }
 RTM_EXPORT(gmtime_r);
@@ -218,7 +215,7 @@ struct tm* localtime_r(const time_t* t, struct tm* r)
 {
     time_t local_tz;
 
-    local_tz = *t + RT_LIBC_FIXED_TIMEZONE * 3600;
+    local_tz = *t + tz_get() * 3600;
     return gmtime_r(&local_tz, r);
 }
 RTM_EXPORT(localtime_r);
@@ -235,13 +232,36 @@ time_t mktime(struct tm * const t)
     time_t timestamp;
 
     timestamp = timegm(t);
-    timestamp = timestamp - 3600 * RT_LIBC_FIXED_TIMEZONE;
+    timestamp = timestamp - 3600 * tz_get();
     return timestamp;
 }
 RTM_EXPORT(mktime);
 
 char* asctime_r(const struct tm *t, char *buf)
 {
+    /* Checking input validity */
+    if ((int)rt_strlen(days) <= (t->tm_wday << 2) || (int)rt_strlen(months) <= (t->tm_mon << 2))
+    {
+        LOG_W("asctime_r: the input parameters exceeded the limit, please check it.");
+        *(int*) buf = *(int*) days;
+        *(int*) (buf + 4) = *(int*) months;
+        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, 2000 / 100);
+        num2str(buf + 22, 2000 % 100);
+        buf[24] = '\n';
+        buf[25] = '\0';
+        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));
@@ -426,7 +446,7 @@ int gettimeofday(struct timeval *tv, struct timezone *tz)
     if(tz != RT_NULL)
     {
         tz->tz_dsttime = DST_NONE;
-        tz->tz_minuteswest = -(RT_LIBC_FIXED_TIMEZONE * 60);
+        tz->tz_minuteswest = -(tz_get() * 60);
     }
 
     if (tv != RT_NULL && get_timeval(tv) == RT_EOK)
@@ -449,7 +469,6 @@ int settimeofday(const struct timeval *tv, const struct timezone *tz)
      * Thus, the following is purely of historic interest.
      */
     if (tv != RT_NULL
-        && tv->tv_sec >= 0
         && tv->tv_usec >= 0
         && set_timeval((struct timeval *)tv) == RT_EOK)
     {
@@ -468,38 +487,47 @@ RTM_EXPORT(difftime);
 RTM_EXPORT(strftime);
 
 #ifdef RT_USING_POSIX
-static struct timeval _timevalue;
-static int clock_time_system_init()
+
+#ifdef RT_USING_RTC
+static volatile struct timeval _timevalue;
+static int _rt_clock_time_system_init()
 {
-    time_t time;
+    register rt_base_t level;
+    time_t time = 0;
     rt_tick_t tick;
     rt_device_t device;
 
-    time = 0;
-
-#ifdef RT_USING_RTC
     device = rt_device_find("rtc");
     if (device != RT_NULL)
     {
         /* get realtime seconds */
-        rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
+        if(rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time) == RT_EOK)
+        {
+            level = rt_hw_interrupt_disable();
+            tick = rt_tick_get(); /* get tick */
+            _timevalue.tv_usec = (tick%RT_TICK_PER_SECOND) * MICROSECOND_PER_TICK;
+            _timevalue.tv_sec = time - tick/RT_TICK_PER_SECOND - 1;
+            rt_hw_interrupt_enable(level);
+            return 0;
+        }
     }
-#else
-    LOG_W("Cannot find a RTC device to provide time!");
-#endif
 
-    /* get tick */
-    tick = rt_tick_get();
+    level = rt_hw_interrupt_disable();
+    _timevalue.tv_usec = 0;
+    _timevalue.tv_sec = 0;
+    rt_hw_interrupt_enable(level);
 
-    _timevalue.tv_usec = (tick%RT_TICK_PER_SECOND) * MICROSECOND_PER_TICK;
-    _timevalue.tv_sec = time - tick/RT_TICK_PER_SECOND - 1;
-
-    return 0;
+    return -1;
 }
-INIT_COMPONENT_EXPORT(clock_time_system_init);
+INIT_COMPONENT_EXPORT(_rt_clock_time_system_init);
+#endif /* RT_USING_RTC */
 
 int clock_getres(clockid_t clockid, struct timespec *res)
 {
+#ifndef RT_USING_RTC
+    LOG_W("Cannot find a RTC device to save time!");
+    return -1;
+#else
     int ret = 0;
 
     if (res == RT_NULL)
@@ -529,11 +557,16 @@ int clock_getres(clockid_t clockid, struct timespec *res)
     }
 
     return ret;
+#endif /* RT_USING_RTC */
 }
 RTM_EXPORT(clock_getres);
 
 int clock_gettime(clockid_t clockid, struct timespec *tp)
 {
+#ifndef RT_USING_RTC
+    LOG_W("Cannot find a RTC device to save time!");
+    return -1;
+#else
     int ret = 0;
 
     if (tp == RT_NULL)
@@ -546,11 +579,14 @@ int clock_gettime(clockid_t clockid, struct timespec *tp)
     {
     case CLOCK_REALTIME:
         {
-            /* get tick */
-            int tick = rt_tick_get();
+            int tick;
+            register rt_base_t level;
 
+            level = rt_hw_interrupt_disable();
+            tick = rt_tick_get(); /* get tick */
             tp->tv_sec  = _timevalue.tv_sec + tick / RT_TICK_PER_SECOND;
             tp->tv_nsec = (_timevalue.tv_usec + (tick % RT_TICK_PER_SECOND) * MICROSECOND_PER_TICK) * 1000;
+            rt_hw_interrupt_enable(level);
         }
         break;
 
@@ -574,11 +610,17 @@ int clock_gettime(clockid_t clockid, struct timespec *tp)
     }
 
     return ret;
+#endif /* RT_USING_RTC */
 }
 RTM_EXPORT(clock_gettime);
 
 int clock_settime(clockid_t clockid, const struct timespec *tp)
 {
+#ifndef RT_USING_RTC
+    LOG_W("Cannot find a RTC device to save time!");
+    return -1;
+#else
+    register rt_base_t level;
     int second;
     rt_tick_t tick;
     rt_device_t device;
@@ -586,38 +628,36 @@ int clock_settime(clockid_t clockid, const struct timespec *tp)
     if ((clockid != CLOCK_REALTIME) || (tp == RT_NULL))
     {
         rt_set_errno(EINVAL);
-
         return -1;
     }
 
     /* get second */
     second = tp->tv_sec;
-    /* get tick */
-    tick = rt_tick_get();
 
+    level = rt_hw_interrupt_disable();
+    tick = rt_tick_get(); /* get tick */
     /* update timevalue */
     _timevalue.tv_usec = MICROSECOND_PER_SECOND - (tick % RT_TICK_PER_SECOND) * MICROSECOND_PER_TICK;
     _timevalue.tv_sec = second - tick/RT_TICK_PER_SECOND - 1;
+    rt_hw_interrupt_enable(level);
 
-#ifdef RT_USING_RTC
     /* update for RTC device */
     device = rt_device_find("rtc");
     if (device != RT_NULL)
     {
         /* set realtime seconds */
-        rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &second);
+        if(rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &second) == RT_EOK)
+        {
+            return 0;
+        }
     }
-    else
-#else
-    LOG_W("Cannot find a RTC device to save time!");
-#endif
-        return -1;
 
-    return 0;
+    return -1;
+#endif /* RT_USING_RTC */
 }
 RTM_EXPORT(clock_settime);
 
-int clock_time_to_tick(const struct timespec *time)
+int rt_timespec_to_tick(const struct timespec *time)
 {
     int tick;
     int nsecond, second;
@@ -648,6 +688,32 @@ int clock_time_to_tick(const struct timespec *time)
 
     return tick;
 }
-RTM_EXPORT(clock_time_to_tick);
+RTM_EXPORT(rt_timespec_to_tick);
 
 #endif /* RT_USING_POSIX */
+
+
+/* timezone */
+#ifndef RT_LIBC_DEFAULT_TIMEZONE
+#define RT_LIBC_DEFAULT_TIMEZONE    8
+#endif
+
+static volatile int8_t _current_timezone = RT_LIBC_DEFAULT_TIMEZONE;
+
+void tz_set(int8_t tz)
+{
+    register rt_base_t level;
+    level = rt_hw_interrupt_disable();
+    _current_timezone = tz;
+    rt_hw_interrupt_enable(level);
+}
+
+int8_t tz_get(void)
+{
+    return _current_timezone;
+}
+
+int8_t tz_is_dst(void)
+{
+    return 0;
+}
diff --git a/components/libc/compilers/common/unistd.c b/components/libc/compilers/common/unistd.c
deleted file mode 100644
index 9a457c4200..0000000000
--- a/components/libc/compilers/common/unistd.c
+++ /dev/null
@@ -1,119 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2020-09-01     Meco Man     first Version
- * 2021-02-12     Meco Man     move all functions located in <pthread_sleep.c> to this file
- */
-
-#include <unistd.h>
-#include <rtthread.h>
-#include <rthw.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)*/
-}
-#else
-int isatty(int fd)
-{
-    if (fd >=0 && fd < 3)
-    {
-        return 1;
-    }
-    else
-    {
-        return 0;
-    }
-}
-#endif
-RTM_EXPORT(isatty);
-
-char *ttyname(int fd)
-{
-    return "/dev/tty"; /* TODO: need to add more specific */
-}
-RTM_EXPORT(ttyname);
-
-unsigned int sleep(unsigned int seconds)
-{
-    if (rt_thread_self() != RT_NULL)
-    {
-        rt_thread_delay(seconds * RT_TICK_PER_SECOND);
-    }
-    else /* scheduler has not run yet */
-    {
-        while(seconds > 0)
-        {
-            rt_hw_us_delay(1000000u);
-            seconds --;
-        }
-    }
-
-    return 0;
-}
-RTM_EXPORT(sleep);
-
-int usleep(useconds_t usec)
-{
-    if (rt_thread_self() != RT_NULL)
-    {
-        rt_thread_mdelay(usec / 1000u);
-    }
-    else  /* scheduler has not run yet */
-    {
-        rt_hw_us_delay(usec / 1000u);
-    }
-    rt_hw_us_delay(usec % 1000u);
-
-    return 0;
-}
-RTM_EXPORT(usleep);
-
-pid_t gettid(void)
-{
-    /*TODO*/
-    return 0;
-}
-
-pid_t getpid(void)
-{
-    return gettid();
-}
-RTM_EXPORT(getpid);
-
-pid_t getppid(void)
-{
-    return 0;
-}
-RTM_EXPORT(getppid);
-
-uid_t getuid(void)
-{
-    return 0; /*ROOT*/
-}
-RTM_EXPORT(getuid);
-
-uid_t geteuid(void)
-{
-    return 0; /*ROOT*/
-}
-RTM_EXPORT(geteuid);
-
-gid_t getgid(void)
-{
-    return 0; /*ROOT*/
-}
-RTM_EXPORT(getgid);
-
-gid_t getegid(void)
-{
-    return 0; /*ROOT*/
-}
-RTM_EXPORT(getegid);
diff --git a/components/libc/compilers/dlib/SConscript b/components/libc/compilers/dlib/SConscript
index 75a5812fab..39707abc61 100644
--- a/components/libc/compilers/dlib/SConscript
+++ b/components/libc/compilers/dlib/SConscript
@@ -1,26 +1,20 @@
 from building import *
-
 Import('rtconfig')
 
 src   = Glob('*.c')
-cwd   = GetCurrentDir()
 group = []
 
-CPPPATH    = [cwd]
 CPPDEFINES = ['RT_USING_DLIBC']
 
 if rtconfig.PLATFORM == 'iar':
-
-    if GetDepend('RT_USING_DFS'):
+    if GetDepend('RT_USING_POSIX'):
         from distutils.version import LooseVersion
         from iar import IARVersion
 
         CPPDEFINES = CPPDEFINES + ['_DLIB_FILE_DESCRIPTOR']
-
         if LooseVersion(IARVersion()) < LooseVersion("8.20.1"):
             CPPDEFINES = CPPDEFINES + ['_DLIB_THREAD_SUPPORT']
 
-    group = DefineGroup('libc', src, depend = ['RT_USING_LIBC'], 
-        CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
+    group = DefineGroup('libc', src, depend = ['RT_USING_LIBC'], CPPDEFINES = CPPDEFINES)
 
 Return('group')
diff --git a/components/libc/compilers/dlib/libc.c b/components/libc/compilers/dlib/libc.c
deleted file mode 100644
index d0dca7c5f6..0000000000
--- a/components/libc/compilers/dlib/libc.c
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      the first version
- */
-#include <stdio.h>
-#include <stdlib.h>
-
-#include <rtthread.h>
-
-#include "libc.h"
-
-#ifdef RT_USING_PTHREADS
-#include <pthread.h>
-#endif
-
-int libc_system_init(void)
-{
-#if defined(RT_USING_DFS) && defined(RT_USING_DFS_DEVFS)
-    rt_device_t dev_console;
-
-    dev_console = rt_console_get_device();
-    if (dev_console)
-    {
-    #if defined(RT_USING_POSIX)
-        libc_stdio_set_console(dev_console->parent.name, O_RDWR);
-    #else
-        libc_stdio_set_console(dev_console->parent.name, O_WRONLY);
-    #endif
-    }
-#endif
-
-#if defined (RT_USING_PTHREADS) && !defined (RT_USING_COMPONENTS_INIT)
-    pthread_system_init();
-#endif
-
-    return 0;
-}
-INIT_COMPONENT_EXPORT(libc_system_init);
-
diff --git a/components/libc/compilers/dlib/libc.h b/components/libc/compilers/dlib/libc.h
deleted file mode 100644
index fc3cafca78..0000000000
--- a/components/libc/compilers/dlib/libc.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      the first version
- */
-
-#ifndef __RTT_LIBC_H__
-#define __RTT_LIBC_H__
-
-#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);
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/components/libc/compilers/dlib/stdio.c b/components/libc/compilers/dlib/stdio.c
deleted file mode 100644
index c11157d759..0000000000
--- a/components/libc/compilers/dlib/stdio.c
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      implement stdio for IAR dlib.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <rtthread.h>
-#include "libc.h"
-
-#if defined(RT_USING_DFS) && defined(RT_USING_DFS_DEVFS)
-#include <dfs_posix.h>
-
-#define STDIO_DEVICE_NAME_MAX   32
-
-static int std_fd = -1;
-int libc_stdio_set_console(const char* device_name, int mode)
-{
-    int fd;
-    char name[STDIO_DEVICE_NAME_MAX];
-
-    snprintf(name, sizeof(name) - 1, "/dev/%s", device_name);
-    name[STDIO_DEVICE_NAME_MAX - 1] = '\0';
-
-    fd = open(name, mode, 0);
-    if (fd >= 0)
-    {
-        if (std_fd >= 0)
-        {
-            close(std_fd);
-        }
-        std_fd = fd;
-    }
-
-    return std_fd;
-}
-
-int libc_stdio_get_console(void) {
-    return std_fd;
-}
-
-int libc_stdio_read(void *buffer, size_t size)
-{
-    return read(std_fd, buffer, size);
-}
-
-int libc_stdio_write(const void *buffer, size_t size)
-{
-    return write(std_fd, buffer, size);
-}
-#endif
diff --git a/components/libc/compilers/dlib/syscall_close.c b/components/libc/compilers/dlib/syscall_close.c
index 7ed1cc2f2d..2897c2418a 100644
--- a/components/libc/compilers/dlib/syscall_close.c
+++ b/components/libc/compilers/dlib/syscall_close.c
@@ -8,10 +8,8 @@
  * 2015-01-28     Bernard      first version
  */
 #include <rtthread.h>
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
-#endif
 #include <yfuns.h>
+#include <unistd.h>
 
 #pragma module_name = "?__close"
 int __close(int handle)
@@ -20,10 +18,9 @@ int __close(int handle)
         handle == _LLIO_STDERR ||
         handle == _LLIO_STDIN)
         return _LLIO_ERROR;
-
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     return close(handle);
 #else
-    return 0;
-#endif
+    return _LLIO_ERROR;
+#endif /* RT_USING_POSIX */
 }
diff --git a/components/libc/compilers/dlib/syscall_lseek.c b/components/libc/compilers/dlib/syscall_lseek.c
index 47a069bf0a..4ea55ef1c3 100644
--- a/components/libc/compilers/dlib/syscall_lseek.c
+++ b/components/libc/compilers/dlib/syscall_lseek.c
@@ -8,10 +8,8 @@
  * 2015-01-28     Bernard      first version
  */
 #include <rtthread.h>
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
-#endif
 #include <yfuns.h>
+#include <unistd.h>
 
 #pragma module_name = "?__lseek"
 long __lseek(int handle, long offset, int whence)
@@ -20,10 +18,9 @@ long __lseek(int handle, long offset, int whence)
         handle == _LLIO_STDERR ||
         handle == _LLIO_STDIN)
         return _LLIO_ERROR;
-
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     return lseek(handle, offset, whence);
 #else
     return _LLIO_ERROR;
-#endif
+#endif /* RT_USING_POSIX */
 }
diff --git a/components/libc/compilers/dlib/syscall_open.c b/components/libc/compilers/dlib/syscall_open.c
index 37bfcecb47..8fb3c3a11f 100644
--- a/components/libc/compilers/dlib/syscall_open.c
+++ b/components/libc/compilers/dlib/syscall_open.c
@@ -10,17 +10,13 @@
 
 #include <rtthread.h>
 #include <yfuns.h>
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
-#endif
+#include <fcntl.h>
 
 #pragma module_name = "?__open"
 
 int __open(const char *filename, int mode)
 {
-#ifndef RT_USING_DFS
-  return _LLIO_ERROR;
-#else
+#ifdef RT_USING_POSIX
   int handle;
   int open_mode = O_RDONLY;
 
@@ -70,5 +66,7 @@ int __open(const char *filename, int mode)
     return _LLIO_ERROR;
 
   return handle;
-#endif
+#else
+  return _LLIO_ERROR;
+#endif /* RT_USING_POSIX */
 }
diff --git a/components/libc/compilers/dlib/syscall_read.c b/components/libc/compilers/dlib/syscall_read.c
index afb661bd93..74cedb966a 100644
--- a/components/libc/compilers/dlib/syscall_read.c
+++ b/components/libc/compilers/dlib/syscall_read.c
@@ -9,35 +9,39 @@
  */
 
 #include <rtthread.h>
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
-#endif
 #include <yfuns.h>
+#include <unistd.h>
+#ifdef RT_USING_POSIX
 #include "libc.h"
+#endif
+
+#define DBG_TAG    "dlib.syscall_read"
+#define DBG_LVL    DBG_INFO
+#include <rtdbg.h>
 
 #pragma module_name = "?__read"
 size_t __read(int handle, unsigned char *buf, size_t len)
 {
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     int size;
-#endif
 
     if (handle == _LLIO_STDIN)
     {
-#ifdef RT_USING_POSIX
-        return libc_stdio_read(buf, len);
-#else
-        return _LLIO_ERROR;
-#endif
+        if (libc_stdio_get_console() < 0)
+        {
+            LOG_W("Do not invoke standard input before initializing libc");
+            return 0;
+        }
+        return read(STDIN_FILENO, buf, len);
     }
-
-    if ((handle == _LLIO_STDOUT) || (handle == _LLIO_STDERR))
+    else if ((handle == _LLIO_STDOUT) || (handle == _LLIO_STDERR))
+    {
         return _LLIO_ERROR;
+    }
 
-#ifndef RT_USING_DFS
-    return _LLIO_ERROR;
-#else
     size = read(handle, buf, len);
     return size;
-#endif
+#else
+    return _LLIO_ERROR;
+#endif /* RT_USING_POSIX */
 }
diff --git a/components/libc/compilers/dlib/syscall_remove.c b/components/libc/compilers/dlib/syscall_remove.c
index 7d74236f4c..05bfbb67ae 100644
--- a/components/libc/compilers/dlib/syscall_remove.c
+++ b/components/libc/compilers/dlib/syscall_remove.c
@@ -8,17 +8,15 @@
  * 2015-01-28     Bernard      first version
  */
 #include <rtthread.h>
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
-#endif
 #include <yfuns.h>
+#include <unistd.h>
 
 #pragma module_name = "?remove"
 int remove(const char *val)
 {
-#ifndef RT_USING_DFS
-    return -1;
-#else
+#ifdef RT_USING_POSIX
     return unlink(val);
-#endif
+#else
+    return -1;
+#endif /* RT_USING_POSIX */
 }
diff --git a/components/libc/compilers/dlib/syscall_write.c b/components/libc/compilers/dlib/syscall_write.c
index de464530b8..ab011c1096 100644
--- a/components/libc/compilers/dlib/syscall_write.c
+++ b/components/libc/compilers/dlib/syscall_write.c
@@ -9,46 +9,56 @@
  */
 
 #include <rtthread.h>
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
-#endif
 #include <yfuns.h>
+#include <unistd.h>
+#ifdef RT_USING_POSIX
 #include "libc.h"
+#endif
+
+#define DBG_TAG    "dlib.syscall_write"
+#define DBG_LVL    DBG_INFO
+#include <rtdbg.h>
 
 #pragma module_name = "?__write"
 
 size_t __write(int handle, const unsigned char *buf, size_t len)
 {
-#ifdef RT_USING_DFS
+#ifdef RT_USING_POSIX
     int size;
-#endif
+#endif /* RT_USING_POSIX */
 
     if ((handle == _LLIO_STDOUT) || (handle == _LLIO_STDERR))
     {
-#ifndef RT_USING_CONSOLE
-        return _LLIO_ERROR;
-#else
-
 #ifdef RT_USING_POSIX
-        return libc_stdio_write((void*)buf, len);
-#else
+        if (libc_stdio_get_console() < 0)
+        {
+            LOG_W("Do not invoke standard output before initializing libc");
+            return 0;
+        }
+        return write(STDOUT_FILENO, (void*)buf, len);
+#elif defined(RT_USING_CONSOLE)
         rt_device_t console_device;
 
         console_device = rt_console_get_device();
-        if (console_device != 0) rt_device_write(console_device, 0, buf, len);
+        if (console_device != 0)
+        {
+            rt_device_write(console_device, 0, buf, len);
+        }
 
         return len;
-#endif
-#endif
+#else
+        return _LLIO_ERROR;
+#endif /* RT_USING_POSIX */
+    }
+    else if (handle == _LLIO_STDIN)
+    {
+        return _LLIO_ERROR;
     }
 
-    if (handle == _LLIO_STDIN) return _LLIO_ERROR;
-
-#ifndef RT_USING_DFS
-    return _LLIO_ERROR;
-#else
+#ifdef RT_USING_POSIX
     size = write(handle, buf, len);
     return size;
-#endif
+#else
+    return _LLIO_ERROR;
+#endif /* RT_USING_POSIX */
 }
-
diff --git a/components/libc/compilers/dlib/syscalls.c b/components/libc/compilers/dlib/syscalls.c
index e1c9562b3a..1ee6a3bc12 100644
--- a/components/libc/compilers/dlib/syscalls.c
+++ b/components/libc/compilers/dlib/syscalls.c
@@ -6,7 +6,6 @@
  * Change Logs:
  * Date           Author       Notes
  * 2021-02-13     Meco Man     implement exit() and abort()
- * 2021-02-20     Meco Man     add system()
  */
 #include <rtthread.h>
 
@@ -17,9 +16,3 @@ void __exit (int status)
     __rt_libc_exit(status);
     while(1);
 }
-
-int system(const char * string)
-{
-    extern int __rt_libc_system(const char *string);
-    return __rt_libc_system(string);
-}
diff --git a/components/libc/compilers/gcc/SConscript b/components/libc/compilers/gcc/SConscript
new file mode 100644
index 0000000000..4c815c49b8
--- /dev/null
+++ b/components/libc/compilers/gcc/SConscript
@@ -0,0 +1,15 @@
+# RT-Thread building script for bridge
+
+import os
+from building import *
+
+cwd = GetCurrentDir()
+objs = []
+list = os.listdir(cwd)
+
+for d in list:
+    path = os.path.join(cwd, d)
+    if os.path.isfile(os.path.join(path, 'SConscript')):
+        objs = objs + SConscript(os.path.join(d, 'SConscript'))
+
+Return('objs')
diff --git a/components/libc/compilers/newlib/README.md b/components/libc/compilers/gcc/newlib/README.md
index 385f329a4f..62172e6a55 100644
--- a/components/libc/compilers/newlib/README.md
+++ b/components/libc/compilers/gcc/newlib/README.md
@@ -6,4 +6,5 @@ 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
+https://sourceware.org/newlib/libc.html#Reentrancy
+
diff --git a/components/libc/compilers/gcc/newlib/SConscript b/components/libc/compilers/gcc/newlib/SConscript
new file mode 100644
index 0000000000..ae50098dec
--- /dev/null
+++ b/components/libc/compilers/gcc/newlib/SConscript
@@ -0,0 +1,20 @@
+from building import *
+Import('rtconfig')
+
+src = []
+cwd = GetCurrentDir()
+group = []
+LIBS = ['m'] # link libm
+CPPDEFINES = ['RT_USING_NEWLIB']
+CPPPATH = [cwd]
+
+if rtconfig.PLATFORM == 'gcc':
+    if GetDepend('RT_USING_LIBC'):
+        LIBS += ['c'] # link libc
+        src += Glob('*.c')
+    else:
+        src += ['syscalls.c']
+
+    group = DefineGroup('libc', src, depend = [], CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES, LIBS = LIBS)
+
+Return('group')
diff --git a/components/libc/compilers/newlib/libc_syms.c b/components/libc/compilers/gcc/newlib/libc_syms.c
index aaf6980d6b..aaf6980d6b 100644
--- a/components/libc/compilers/newlib/libc_syms.c
+++ b/components/libc/compilers/gcc/newlib/libc_syms.c
diff --git a/components/libc/compilers/newlib/machine/time.h b/components/libc/compilers/gcc/newlib/machine/time.h
index ff754d2473..ff754d2473 100644
--- a/components/libc/compilers/newlib/machine/time.h
+++ b/components/libc/compilers/gcc/newlib/machine/time.h
diff --git a/components/libc/compilers/newlib/syscalls.c b/components/libc/compilers/gcc/newlib/syscalls.c
index e01dc59eb6..f95e695a85 100644
--- a/components/libc/compilers/newlib/syscalls.c
+++ b/components/libc/compilers/gcc/newlib/syscalls.c
@@ -12,22 +12,89 @@
  */
 
 #include <reent.h>
-#include <errno.h>
-#include <stdio.h>
-#include <sys/time.h>
-
 #include <rtthread.h>
-
-#ifdef RT_USING_DFS
-#include <dfs_posix.h>
+#include <stdio.h>
+#include <string.h>
+#include <stddef.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+#ifdef RT_USING_POSIX
+#include "libc.h"
 #endif
-
 #ifdef RT_USING_MODULE
 #include <dlmodule.h>
 #endif
 
-/* Reentrant versions of system calls.  */
+#define DBG_TAG    "newlib.syscalls"
+#define DBG_LVL    DBG_INFO
+#include <rtdbg.h>
+
+#ifdef RT_USING_HEAP /* Memory routine */
+void *_malloc_r (struct _reent *ptr, size_t size)
+{
+    void* result;
+
+    result = (void*)rt_malloc (size);
+    if (result == RT_NULL)
+    {
+        ptr->_errno = ENOMEM;
+    }
+
+    return result;
+}
+
+void *_realloc_r (struct _reent *ptr, void *old, size_t newlen)
+{
+    void* result;
+
+    result = (void*)rt_realloc (old, newlen);
+    if (result == RT_NULL)
+    {
+        ptr->_errno = ENOMEM;
+    }
+
+    return result;
+}
+
+void *_calloc_r (struct _reent *ptr, size_t size, size_t len)
+{
+    void* result;
+
+    result = (void*)rt_calloc (size, len);
+    if (result == RT_NULL)
+    {
+        ptr->_errno = ENOMEM;
+    }
+
+    return result;
+}
+
+void _free_r (struct _reent *ptr, void *addr)
+{
+    rt_free (addr);
+}
+
+#else
+void *
+_sbrk_r(struct _reent *ptr, ptrdiff_t incr)
+{
+    LOG_E("Please enable RT_USING_HEAP or RT_USING_LIBC");
+    RT_ASSERT(0);
+    return RT_NULL;
+}
+#endif /*RT_USING_HEAP*/
+
+void __libc_init_array(void)
+{
+    /* we not use __libc init_aray to initialize C++ objects */
+    /* __libc_init_array is ARM code, not Thumb; it will cause a hardfault. */
+}
+
+#ifdef RT_USING_LIBC
 
+/* Reentrant versions of system calls.  */
 #ifndef _REENT_ONLY
 int *__errno ()
 {
@@ -42,39 +109,29 @@ int _getpid_r(struct _reent *ptr)
 
 int _close_r(struct _reent *ptr, int fd)
 {
-#ifndef RT_USING_DFS
-    /* return "not supported" */
-    ptr->_errno = ENOTSUP;
-    return -1;
-#else
     return close(fd);
-#endif
 }
 
 int _execve_r(struct _reent *ptr, const char * name, char *const *argv, char *const *env)
 {
-    /* return "not supported" */
     ptr->_errno = ENOTSUP;
     return -1;
 }
 
 int _fcntl_r(struct _reent *ptr, int fd, int cmd, int arg)
 {
-    /* return "not supported" */
     ptr->_errno = ENOTSUP;
     return -1;
 }
 
 int _fork_r(struct _reent *ptr)
 {
-    /* return "not supported" */
     ptr->_errno = ENOTSUP;
     return -1;
 }
 
 int _fstat_r(struct _reent *ptr, int fd, struct stat *pstat)
 {
-    /* return "not supported" */
     ptr->_errno = ENOTSUP;
     return -1;
 }
@@ -93,198 +150,147 @@ int _isatty_r(struct _reent *ptr, int fd)
 
 int _kill_r(struct _reent *ptr, int pid, int sig)
 {
-    /* return "not supported" */
     ptr->_errno = ENOTSUP;
     return -1;
 }
 
 int _link_r(struct _reent *ptr, const char *old, const char *new)
 {
-    /* return "not supported" */
     ptr->_errno = ENOTSUP;
     return -1;
 }
 
-_off_t _lseek_r(struct _reent *ptr, int fd, _off_t pos, int whence)
+int _wait_r(struct _reent *ptr, int *status)
 {
-#ifndef RT_USING_DFS
-    /* return "not supported" */
     ptr->_errno = ENOTSUP;
     return -1;
-#else
+}
+
+mode_t umask(mode_t mask)
+{
+    return 022;
+}
+
+int flock(int fd, int operation)
+{
+    return 0;
+}
+
+_off_t _lseek_r(struct _reent *ptr, int fd, _off_t pos, int whence)
+{
+#ifdef RT_USING_POSIX
     _off_t rc;
 
     rc = lseek(fd, pos, whence);
     return rc;
-#endif
+#else
+    ptr->_errno = ENOTSUP;
+    return -1;
+#endif /* RT_USING_POSIX */
 }
 
 int _mkdir_r(struct _reent *ptr, const char *name, int mode)
 {
-#ifndef RT_USING_DFS
-    /* return "not supported" */
-    ptr->_errno = ENOTSUP;
-    return -1;
-#else
+#ifdef RT_USING_POSIX
     int rc;
 
     rc = mkdir(name, mode);
     return rc;
-#endif
+#else
+    ptr->_errno = ENOTSUP;
+    return -1;
+#endif /* RT_USING_POSIX */
 }
 
 int _open_r(struct _reent *ptr, const char *file, int flags, int mode)
 {
-#ifndef RT_USING_DFS
-    /* return "not supported" */
-    ptr->_errno = ENOTSUP;
-    return -1;
-#else
+#ifdef RT_USING_POSIX
     int rc;
-
     rc = open(file, flags, mode);
     return rc;
-#endif
+#else
+    ptr->_errno = ENOTSUP;
+    return -1;
+#endif /* RT_USING_POSIX */
 }
 
 _ssize_t _read_r(struct _reent *ptr, int fd, void *buf, size_t nbytes)
 {
-#ifndef RT_USING_DFS
-    /* return "not supported" */
-    ptr->_errno = ENOTSUP;
-    return -1;
-#else
+#ifdef RT_USING_POSIX
     _ssize_t rc;
-
+    if (libc_stdio_get_console() < 0 && fd == STDIN_FILENO)
+    {
+        LOG_W("Do not invoke standard input before initializing libc");
+        return 0;
+    }
     rc = read(fd, buf, nbytes);
     return rc;
-#endif
+#else
+    ptr->_errno = ENOTSUP;
+    return -1;
+#endif /* RT_USING_POSIX */
 }
 
 int _rename_r(struct _reent *ptr, const char *old, const char *new)
 {
-#ifndef RT_USING_DFS
-    /* return "not supported" */
-    ptr->_errno = ENOTSUP;
-    return -1;
-#else
+#ifdef RT_USING_POSIX
     int rc;
 
     rc = rename(old, new);
     return rc;
-#endif
+#else
+    ptr->_errno = ENOTSUP;
+    return -1;
+#endif /* RT_USING_POSIX */
 }
 
 int _stat_r(struct _reent *ptr, const char *file, struct stat *pstat)
 {
-#ifndef RT_USING_DFS
-    /* return "not supported" */
-    ptr->_errno = ENOTSUP;
-    return -1;
-#else
+#ifdef RT_USING_POSIX
     int rc;
 
     rc = stat(file, pstat);
     return rc;
-#endif
-}
-
-int _unlink_r(struct _reent *ptr, const char *file)
-{
-#ifndef RT_USING_DFS
-    /* return "not supported" */
+#else
     ptr->_errno = ENOTSUP;
     return -1;
-#else
-    return unlink(file);
-#endif
+#endif /* RT_USING_POSIX */
 }
 
-int _wait_r(struct _reent *ptr, int *status)
+int _unlink_r(struct _reent *ptr, const char *file)
 {
-    /* return "not supported" */
+#ifdef RT_USING_POSIX
+    return unlink(file);
+#else
     ptr->_errno = ENOTSUP;
     return -1;
+#endif /* RT_USING_POSIX */
 }
 
 _ssize_t _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)
 {
-#ifndef RT_USING_DFS
-#ifdef RT_USING_DEVICE
-    if (fileno(stdout) == fd)
+#ifdef RT_USING_POSIX
+    _ssize_t rc;
+    if (libc_stdio_get_console() < 0 && fd == STDOUT_FILENO)
     {
-        rt_device_t console;
-
-        console = rt_console_get_device();
-        if (console) return rt_device_write(console, -1, buf, nbytes);
+        LOG_W("Do not invoke standard output before initializing libc");
+        return 0;
     }
-
-    return 0;
-#else
-    /* return "not supported" */
-    ptr->_errno = ENOTSUP;
-    return -1;
-#endif /*RT_USING_DEVICE*/
-#else
-    _ssize_t rc;
-
     rc = write(fd, buf, nbytes);
     return rc;
-#endif
-}
-
-#ifdef RT_USING_HEAP /* Memory routine */
-void *_malloc_r (struct _reent *ptr, size_t size)
-{
-    void* result;
-
-    result = (void*)rt_malloc (size);
-    if (result == RT_NULL)
+#elif defined(RT_USING_CONSOLE)
+    if (STDOUT_FILENO == fd)
     {
-        ptr->_errno = ENOMEM;
-    }
-
-    return result;
-}
-
-void *_realloc_r (struct _reent *ptr, void *old, size_t newlen)
-{
-    void* result;
-
-    result = (void*)rt_realloc (old, newlen);
-    if (result == RT_NULL)
-    {
-        ptr->_errno = ENOMEM;
-    }
-
-    return result;
-}
-
-void *_calloc_r (struct _reent *ptr, size_t size, size_t len)
-{
-    void* result;
+        rt_device_t console;
 
-    result = (void*)rt_calloc (size, len);
-    if (result == RT_NULL)
-    {
-        ptr->_errno = ENOMEM;
+        console = rt_console_get_device();
+        if (console)
+            return rt_device_write(console, -1, buf, nbytes);
     }
-
-    return result;
-}
-
-void _free_r (struct _reent *ptr, void *addr)
-{
-    rt_free (addr);
-}
-
-#else
-void *
-_sbrk_r(struct _reent *ptr, ptrdiff_t incr)
-{
-    return RT_NULL;
+#endif /* RT_USING_POSIX */
+    ptr->_errno = ENOTSUP;
+    return -1;
 }
-#endif /*RT_USING_HEAP*/
 
 /* for exit() and abort() */
 __attribute__ ((noreturn)) void _exit (int status)
@@ -294,29 +300,10 @@ __attribute__ ((noreturn)) void _exit (int status)
     while(1);
 }
 
-void _system(const char *s)
-{
-    extern int __rt_libc_system(const char *string);
-    __rt_libc_system(s);
-}
-
-void __libc_init_array(void)
-{
-    /* we not use __libc init_aray to initialize C++ objects */
-}
-
-mode_t umask(mode_t mask)
-{
-    return 022;
-}
-
-int flock(int fd, int operation)
-{
-    return 0;
-}
-
 /*
 These functions are implemented and replaced by the 'common/time.c' file
 int _gettimeofday_r(struct _reent *ptr, struct timeval *__tp, void *__tzp);
 _CLOCK_T_  _times_r(struct _reent *ptr, struct tms *ptms);
 */
+
+#endif /* RT_USING_LIBC */
diff --git a/components/libc/compilers/gcc/partial/SConscript b/components/libc/compilers/gcc/partial/SConscript
new file mode 100644
index 0000000000..4c815c49b8
--- /dev/null
+++ b/components/libc/compilers/gcc/partial/SConscript
@@ -0,0 +1,15 @@
+# RT-Thread building script for bridge
+
+import os
+from building import *
+
+cwd = GetCurrentDir()
+objs = []
+list = os.listdir(cwd)
+
+for d in list:
+    path = os.path.join(cwd, d)
+    if os.path.isfile(os.path.join(path, 'SConscript')):
+        objs = objs + SConscript(os.path.join(d, 'SConscript'))
+
+Return('objs')
diff --git a/components/libc/compilers/gcc/partial/mips/SConscript b/components/libc/compilers/gcc/partial/mips/SConscript
new file mode 100644
index 0000000000..7651233d46
--- /dev/null
+++ b/components/libc/compilers/gcc/partial/mips/SConscript
@@ -0,0 +1,20 @@
+from shutil import copy
+from building import *
+
+Import('rtconfig')
+
+src   = []
+cwd   = GetCurrentDir()
+CPPPATH = [cwd]
+group = []
+
+if rtconfig.PLATFORM == 'gcc' and ('mips' in rtconfig.PREFIX): # identify mips gcc tool chain
+    try:
+        # There is no 'sys/select.h' in tthe mips gcc toolchain; it will be copied from 'nogcc/sys/select.h'
+        copy("../../../common/nogcc/sys/select.h", "./sys/select.h")
+    except:
+        pass
+
+    group = DefineGroup('libc', src, depend = [], CPPPATH = CPPPATH)
+
+Return('group')
diff --git a/components/libc/compilers/gcc/partial/mips/readme.md b/components/libc/compilers/gcc/partial/mips/readme.md
new file mode 100644
index 0000000000..a3eeb06c5d
--- /dev/null
+++ b/components/libc/compilers/gcc/partial/mips/readme.md
@@ -0,0 +1,4 @@
+These files don't exist in the mips gcc toolchain. They will be generated by scons automatically , and **DO NOT** change them:
+
+- sys/select.h
+
diff --git a/components/libc/compilers/gcc/partial/mips/sys/select.h b/components/libc/compilers/gcc/partial/mips/sys/select.h
new file mode 100644
index 0000000000..575ad3a1b5
--- /dev/null
+++ b/components/libc/compilers/gcc/partial/mips/sys/select.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2021-07-21     Meco Man     The first version
+ */
+
+#ifndef __SYS_SELECT_H__
+#define __SYS_SELECT_H__
+
+#include <rtconfig.h>
+#include <sys/types.h>
+#include <sys/time.h>
+
+#ifndef  FD_SETSIZE
+#define  FD_SETSIZE  32
+#endif
+
+#ifdef SAL_USING_POSIX
+#ifdef FD_SETSIZE
+#undef FD_SETSIZE
+#endif
+#define FD_SETSIZE      DFS_FD_MAX
+#endif /* SAL_USING_POSIX */
+
+#define   NBBY    8       /* number of bits in a byte */
+
+typedef long    fd_mask;
+
+#define   NFDBITS (sizeof (fd_mask) * NBBY)   /* bits per mask */
+#ifndef   howmany
+#define   howmany(x,y)    (((x)+((y)-1))/(y))
+#endif
+
+#ifndef _SYS_TYPES_FD_SET /* MIPS */
+typedef struct _types_fd_set {
+    fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
+} _types_fd_set;
+#define fd_set _types_fd_set
+
+#define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1L << ((n) % NFDBITS)))
+#define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1L << ((n) % NFDBITS)))
+#define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1L << ((n) % NFDBITS)))
+#define FD_ZERO(p)      memset((void*)(p), 0, sizeof(*(p)))
+#endif /* _SYS_TYPES_FD_SET */
+
+int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout);
+
+#endif /* __SYS_SELECT_H__ */
diff --git a/components/libc/compilers/gcc/partial/readme.md b/components/libc/compilers/gcc/partial/readme.md
new file mode 100644
index 0000000000..959fc29f35
--- /dev/null
+++ b/components/libc/compilers/gcc/partial/readme.md
@@ -0,0 +1,2 @@
+This folder is for some particular targets.
+
diff --git a/components/libc/compilers/newlib/SConscript b/components/libc/compilers/newlib/SConscript
deleted file mode 100644
index 542cdecd40..0000000000
--- a/components/libc/compilers/newlib/SConscript
+++ /dev/null
@@ -1,29 +0,0 @@
-from building import *
-Import('rtconfig')
-
-src = []
-cwd = GetCurrentDir()
-group = []
-LIBS = []
-CPPDEFINES = []
-CPPPATH = [cwd]
-
-if rtconfig.PLATFORM == 'gcc':
-    if GetDepend('RT_USING_LIBC'):
-        CPPDEFINES += ['RT_USING_NEWLIB']
-        # link with libc and libm:
-        # libm is a frequently used lib. Newlib is compiled with -ffunction-sections in
-        # recent GCC tool chains. The linker would just link in the functions that have
-        # been referenced. So setting this won't result in bigger text size.
-        LIBS += ['c', 'm']
-
-        src += Glob('*.c')
-        SrcRemove(src, ['minilib.c'])
-        if GetDepend('RT_USING_MODULE') == False:
-            SrcRemove(src, ['libc_syms.c'])
-    else:
-        src += ['minilib.c']
-
-    group = DefineGroup('libc', src, depend = [], CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES, LIBS = LIBS)
-
-Return('group')
diff --git a/components/libc/compilers/newlib/libc.c b/components/libc/compilers/newlib/libc.c
deleted file mode 100644
index 9834a9a015..0000000000
--- a/components/libc/compilers/newlib/libc.c
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      the first version
- */
-#include <rtthread.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/time.h>
-
-#include "libc.h"
-
-#ifdef RT_USING_PTHREADS
-#include <pthread.h>
-#endif
-
-int _EXFUN(putenv,(char *__string));
-
-int libc_system_init(void)
-{
-#if defined(RT_USING_DFS) & defined(RT_USING_DFS_DEVFS) & defined(RT_USING_CONSOLE)
-    rt_device_t dev_console;
-
-    dev_console = rt_console_get_device();
-    if (dev_console)
-    {
-    #if defined(RT_USING_POSIX)
-        libc_stdio_set_console(dev_console->parent.name, O_RDWR);
-    #else
-        libc_stdio_set_console(dev_console->parent.name, O_WRONLY);
-    #endif
-    }
-
-    /* set PATH and HOME */
-    putenv("PATH=/bin");
-    putenv("HOME=/home");
-#endif
-
-#if defined RT_USING_PTHREADS && !defined RT_USING_COMPONENTS_INIT
-    pthread_system_init();
-#endif
-
-    return 0;
-}
-INIT_COMPONENT_EXPORT(libc_system_init);
diff --git a/components/libc/compilers/newlib/libc.h b/components/libc/compilers/newlib/libc.h
deleted file mode 100644
index c1f76d7605..0000000000
--- a/components/libc/compilers/newlib/libc.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      the first version
- */
-#ifndef __RTT_LIBC_H__
-#define __RTT_LIBC_H__
-
-#ifndef _EXFUN
-#define _EXFUN(name, proto)     name proto
-#endif
-
-#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);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/components/libc/compilers/newlib/minilib.c b/components/libc/compilers/newlib/minilib.c
deleted file mode 100644
index 612554ca66..0000000000
--- a/components/libc/compilers/newlib/minilib.c
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2021-02-23     Meco Man     first version
- */
-
-#include <reent.h>
-#include <rtthread.h>
-
-#ifdef RT_USING_HEAP /* Memory routine */
-#include <sys/errno.h>
-
-void * _malloc_r (struct _reent *ptr, size_t size)
-{
-    void* result;
-
-    result = (void*)rt_malloc (size);
-    if (result == RT_NULL)
-    {
-        ptr->_errno = ENOMEM;
-    }
-
-    return result;
-}
-
-void * _realloc_r (struct _reent *ptr, void *old, size_t newlen)
-{
-    void* result;
-
-    result = (void*)rt_realloc (old, newlen);
-    if (result == RT_NULL)
-    {
-        ptr->_errno = ENOMEM;
-    }
-
-    return result;
-}
-
-void *_calloc_r (struct _reent *ptr, size_t size, size_t len)
-{
-    void* result;
-
-    result = (void*)rt_calloc (size, len);
-    if (result == RT_NULL)
-    {
-        ptr->_errno = ENOMEM;
-    }
-
-    return result;
-}
-
-void _free_r (struct _reent *ptr, void *addr)
-{
-    rt_free (addr);
-}
-
-#else
-void * _sbrk_r(struct _reent *ptr, ptrdiff_t incr)
-{
-    return RT_NULL;
-}
-#endif /*RT_USING_HEAP*/
diff --git a/components/libc/compilers/newlib/stdio.c b/components/libc/compilers/newlib/stdio.c
deleted file mode 100644
index ce5bdb75cb..0000000000
--- a/components/libc/compilers/newlib/stdio.c
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Copyright (c) 2006-2021, RT-Thread Development Team
- *
- * SPDX-License-Identifier: Apache-2.0
- *
- * Change Logs:
- * Date           Author       Notes
- * 2017/10/15     bernard      the first version
- */
-#include <stdio.h>
-#include <stdlib.h>
-
-#include <rtthread.h>
-#include "libc.h"
-
-#define STDIO_DEVICE_NAME_MAX   32
-
-int _EXFUN(fileno, (FILE *));
-
-static FILE* std_console = NULL;
-
-int libc_stdio_set_console(const char* device_name, int mode)
-{
-    FILE *fp;
-    char name[STDIO_DEVICE_NAME_MAX];
-    char *file_mode;
-
-    snprintf(name, sizeof(name) - 1, "/dev/%s", device_name);
-    name[STDIO_DEVICE_NAME_MAX - 1] = '\0';
-
-    if (mode == O_RDWR) file_mode = "r+";
-    else if (mode == O_WRONLY) file_mode = "wb";
-    else file_mode = "rb";
-
-    fp = fopen(name, file_mode);
-    if (fp)
-    {
-        setvbuf(fp, NULL, _IONBF, 0);
-
-        if (std_console)
-        {
-            fclose(std_console);
-            std_console = NULL;
-        }
-        std_console = fp;
-
-        if (mode == O_RDWR)
-        {
-            _GLOBAL_REENT->_stdin  = std_console;
-        }
-        else
-        {
-            _GLOBAL_REENT->_stdin  = NULL;
-        }
-
-        if (mode == O_RDONLY)
-        {
-            _GLOBAL_REENT->_stdout = NULL;
-            _GLOBAL_REENT->_stderr = NULL;
-        }
-        else
-        {
-            _GLOBAL_REENT->_stdout = std_console;
-            _GLOBAL_REENT->_stderr = std_console;
-        }
-
-        _GLOBAL_REENT->__sdidinit = 1;
-    }
-
-    if (std_console) return fileno(std_console);
-
-    return -1;
-}
-
-int libc_stdio_get_console(void) {
-    if (std_console)
-        return fileno(std_console);
-    else
-        return -1;
-}