diff --git a/components/libc/compilers/armlibc/syscalls.c b/components/libc/compilers/armlibc/syscalls.c
index 2dd90cb27c138eeff14e04b108533a2b5b4dea18..f4ced9d3c066e561907d5402847a9f0f44f819e6 100644
--- a/components/libc/compilers/armlibc/syscalls.c
+++ b/components/libc/compilers/armlibc/syscalls.c
@@ -276,10 +276,7 @@ char *_sys_command_string(char *cmd, int len)
 void _ttywrch(int ch)
 {
 #ifdef RT_USING_CONSOLE
-    char c;
-
-    c = (char)ch;
-    rt_kprintf(&c);
+    rt_kprintf("%c", (char)ch);
 #endif /* RT_USING_CONSOLE */
 }
 
@@ -337,10 +334,7 @@ int remove(const char *filename)
 int fputc(int c, FILE *f)
 {
 #ifdef RT_USING_CONSOLE
-    char ch[2] = {0};
-
-    ch[0] = c;
-    rt_kprintf(&ch[0]);
+    rt_kprintf("%c", (char)c);
     return 1;
 #else
     return 0; /* error */
diff --git a/components/libc/compilers/common/compiler_private.h b/components/libc/compilers/common/compiler_private.h
index 2fd9c51f65915985c39be419170399539fc7e0db..96a49efc7a6991f4a706c778b7bbf845efeccf2b 100644
--- a/components/libc/compilers/common/compiler_private.h
+++ b/components/libc/compilers/common/compiler_private.h
@@ -10,8 +10,6 @@
 #ifndef __COMPILER_PRIVATE_H__
 #define __COMPILER_PRIVATE_H__
 
-#include <rtconfig.h>
-
 #define _WARNING_WITHOUT_FS     "Please enable RT_USING_POSIX_FS"
 #define _WARNING_WITHOUT_STDIO  "Please enable RT_USING_POSIX_FS and RT_USING_POSIX_STDIO"
 
diff --git a/components/libc/compilers/common/time.c b/components/libc/compilers/common/time.c
index 8890a3e8307ab3dddce1b19cf9b872a879b37298..256268a3fc7cd4f5fdc06812cb4fb8b4efc0ef5f 100644
--- a/components/libc/compilers/common/time.c
+++ b/components/libc/compilers/common/time.c
@@ -56,8 +56,8 @@ static const short __spm[13] =
     (31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31),
 };
 
-ALIGN(4) static const char days[] = "Sun Mon Tue Wed Thu Fri Sat ";
-ALIGN(4) static const char months[] = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ";
+ALIGN(4) static const char *days = "Sun Mon Tue Wed Thu Fri Sat ";
+ALIGN(4) static const char *months = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ";
 
 static int __isleap(int year)
 {