diff --git a/.vscode/settings.json b/.vscode/settings.json
index 00b8282..5f01d9f 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -42,6 +42,8 @@
         "os_obj.h": "c",
         "os_api.h": "c",
         "os_ring_buffer.h": "c",
-        "os_list.h": "c"
+        "os_list.h": "c",
+        "uartstdio.h": "c",
+        "gpio.h": "c"
     }
 }
\ No newline at end of file
diff --git a/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/include/bsp.h b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/include/bsp.h
index ca7badd..e190424 100644
--- a/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/include/bsp.h
+++ b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/include/bsp.h
@@ -23,18 +23,14 @@ void light_red_off(void);
 void light_green_off(void);
 void light_blue_off(void);
 
-#define BSP_TICKS_PER_SEC 1000U
+#define BSP_TICKS_PER_SEC 10U
 
 
 
 typedef long clock_t;
 extern volatile clock_t* l_tickCtr;
 
-void os_on_startup(void);
-
-void disable_irq(void);
-void enable_irq(void);
-
+void system_init(void);
 void delay_block(clock_t tick);
 
 #endif
\ No newline at end of file
diff --git a/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/include/uart_debug.h b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/include/uart_debug.h
new file mode 100644
index 0000000..9f45426
--- /dev/null
+++ b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/include/uart_debug.h
@@ -0,0 +1,26 @@
+/***************************************************
+* Ceno Real-time Operating System  (CenoRTOS)
+* version 0.1
+* author neroyang
+* email nerosoft@outlook.com
+* time 2019-01-27 
+* 
+* Copyright (C) 2018 CenoCloud. All Rights Reserved 
+*
+* Contract Information：
+* https://www.cenocloud.com
+****************************************************/
+#ifndef __CENO_RTOS_UART_DEBUG__
+#define __CENO_RTOS_UART_DEBUG__
+
+void uart_debug_init(void);
+
+void uart_debug_print(char* str);
+
+void uart_debug_print_char(char str);
+
+void uart_debug_reveive(char* rec);
+
+char uart_debug_reveive_char(void);
+
+#endif //! __CENO_RTOS_UART_DEBUG__
diff --git a/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c
index 9af80d3..f0bf785 100644
--- a/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c
+++ b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c
@@ -15,6 +15,7 @@ void os_on_startup(void){
 }
 
 
+
 void disable_irq(void){
 	__asm	(
 		"CPSID	I\n\t"
diff --git a/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c
new file mode 100644
index 0000000..2aa770e
--- /dev/null
+++ b/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c
@@ -0,0 +1,56 @@
+#include "../include/uart_debug.h"
+#include "TM4C123GH6PM.h"
+
+void uart_debug_init(void){
+	SYSCTL->RCGCUART |= (1<<0);
+	SYSCTL->RCGCGPIO |= (1<<0);
+
+	GPIOA->AFSEL = (1<<1)|(1<<0);
+	GPIOA->PCTL = (1<<0)|(1<<4);
+	GPIOA->DEN = (1<<0)|(1<<1);
+	 
+	UART0->CTL &= ~(1<<0);
+	UART0->IBRD = 104;
+	UART0->FBRD = 11;
+	UART0->LCRH = (0x3<<5);
+	UART0->CC = 0x0;
+
+	UART0->CTL = (1<<0)|(1<<8)|(1<<9);
+}
+
+void uart_debug_print(char* str){
+	while(*str){
+		uart_debug_print_char(*(string++));
+	}
+}
+
+void uart_debug_print_char(char str){
+	while((UART0->FR & (1<<5))!=0);
+	UART0->DR = str;
+}
+
+
+void uart_debug_reveive(char* rec){
+
+}
+
+char uart_debug_reveive_char(void){
+	char c;
+	while((UART0->FR & (1<<1))!=0);
+	c = UART0->DR;
+	return c;
+}
+
+int main(){
+	uart_debug_init();
+	char c;
+	while(1){
+		uart_debug_print("test uart print");
+		uart_debug_reveive(c);
+		switch(c){
+			case '1':
+			break;
+		}
+	}
+
+}
\ No newline at end of file
diff --git a/user/asm/bsp.s b/user/asm/bsp.s
index 84c93e2..6dca4e9 100644
--- a/user/asm/bsp.s
+++ b/user/asm/bsp.s
@@ -136,7 +136,7 @@ os_on_startup:
 	ldr	r2, [r3]
 	ldr	r1, .L13+4
 	umull	r3, r4, r2, r1
-	lsr	r3, r4, #6
+	lsr	r3, r4, #3
 	mov	r0, r3
 	bl	SysTick_Config
 	mov	r1, #0
@@ -151,7 +151,7 @@ os_on_startup:
 	.align	2
 .L13:
 	.word	SystemCoreClock
-	.word	274877907
+	.word	-858993459
 	.size	os_on_startup, .-os_on_startup
 	.align	2
 	.global	disable_irq
@@ -167,7 +167,7 @@ disable_irq:
 	str	fp, [sp, #-4]!
 	add	fp, sp, #0
 	.syntax divided
-@ 19 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c" 1
+@ 20 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c" 1
 	CPSID	I
 	
 @ 0 "" 2
@@ -193,7 +193,7 @@ enable_irq:
 	str	fp, [sp, #-4]!
 	add	fp, sp, #0
 	.syntax divided
-@ 24 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c" 1
+@ 25 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c" 1
 	CPSIE	I
 	
 @ 0 "" 2
diff --git a/user/bin/CenoRTOS.bin b/user/bin/CenoRTOS.bin
index 7633ef6..84ef3bd 100755
Binary files a/user/bin/CenoRTOS.bin and b/user/bin/CenoRTOS.bin differ
diff --git a/user/bin/CenoRTOS.elf b/user/bin/CenoRTOS.elf
index b6d9511..466afde 100755
Binary files a/user/bin/CenoRTOS.elf and b/user/bin/CenoRTOS.elf differ
diff --git a/user/obj/bsp.o b/user/obj/bsp.o
index a98618e..366fe67 100644
Binary files a/user/obj/bsp.o and b/user/obj/bsp.o differ
diff --git a/user/obj/uart_debug.d b/user/obj/uart_debug.d
new file mode 100644
index 0000000..254757a
--- /dev/null
+++ b/user/obj/uart_debug.d
@@ -0,0 +1,3 @@
+obj/uart_debug.o: \
+ /Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c \
+ /Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/../include/uart_debug.h
diff --git a/user/obj/uart_debug.o b/user/obj/uart_debug.o
new file mode 100644
index 0000000..7020e58
Binary files /dev/null and b/user/obj/uart_debug.o differ
diff --git a/user/optimize/bsp.i b/user/optimize/bsp.i
index 7a0d1d1..b51d084 100644
--- a/user/optimize/bsp.i
+++ b/user/optimize/bsp.i
@@ -220,11 +220,7 @@ void light_blue_off(void);
 typedef long clock_t;
 extern volatile clock_t* l_tickCtr;
 
-void os_on_startup(void);
-
-void disable_irq(void);
-void enable_irq(void);
-
+void system_init(void);
 void delay_block(clock_t tick);
 # 3 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/bsp.c" 2
 # 1 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/include/TM4C123GH6PM.h" 1
@@ -3045,12 +3041,13 @@ volatile clock_t* l_tickCtr = &tickCtr;
 extern void os_init(void);
 void os_on_startup(void){
     SystemCoreClockUpdate();
-    SysTick_Config(SystemCoreClock / 1000U);
+    SysTick_Config(SystemCoreClock / 10U);
 
     __NVIC_SetPriority(SysTick_IRQn, 0U);
 }
 
 
+
 void disable_irq(void){
  __asm (
   "CPSID	I\n\t"
diff --git a/user/optimize/interrupt.i b/user/optimize/interrupt.i
index ec459c1..b1c5b71 100644
--- a/user/optimize/interrupt.i
+++ b/user/optimize/interrupt.i
@@ -150,11 +150,7 @@ void light_blue_off(void);
 typedef long clock_t;
 extern volatile clock_t* l_tickCtr;
 
-void os_on_startup(void);
-
-void disable_irq(void);
-void enable_irq(void);
-
+void system_init(void);
 void delay_block(clock_t tick);
 # 3 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/interrupt.c" 2
 
diff --git a/user/optimize/main.i b/user/optimize/main.i
index 475f92a..0d08b8f 100644
--- a/user/optimize/main.i
+++ b/user/optimize/main.i
@@ -220,11 +220,7 @@ void light_blue_off(void);
 typedef long clock_t;
 extern volatile clock_t* l_tickCtr;
 
-void os_on_startup(void);
-
-void disable_irq(void);
-void enable_irq(void);
-
+void system_init(void);
 void delay_block(clock_t tick);
 # 3 "src/main.c" 2
 # 1 "/Users/neroyang/project/Ceno-RTOS/kernel/ceno/include/os_api.h" 1
diff --git a/user/optimize/uart_debug.d b/user/optimize/uart_debug.d
new file mode 100644
index 0000000..7beb793
--- /dev/null
+++ b/user/optimize/uart_debug.d
@@ -0,0 +1,3 @@
+uart_debug.o: \
+ /Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c \
+ /Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/../include/uart_debug.h
diff --git a/user/optimize/uart_debug.i b/user/optimize/uart_debug.i
new file mode 100644
index 0000000..04d8cc8
--- /dev/null
+++ b/user/optimize/uart_debug.i
@@ -0,0 +1,25 @@
+# 1 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c"
+# 1 "/Users/neroyang/project/Ceno-RTOS/user//"
+# 1 "<built-in>"
+# 1 "<command-line>"
+# 1 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c"
+# 1 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/../include/uart_debug.h" 1
+# 16 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/../include/uart_debug.h"
+void uart_debug_init(void);
+
+void uart_debug_print(char* str);
+
+void uart_debug_reveive(char* rec);
+# 2 "/Users/neroyang/project/Ceno-RTOS/board/arch/arm32/ek-TM4C123gxl/TM4C123GH6PM/ceno_os/src/uart_debug.c" 2
+
+void uart_debug_init(void){
+
+}
+
+void uart_debug_print(char* str){
+
+}
+
+void uart_debug_reveive(char* rec){
+
+}