diff --git a/bsp/lpc176x/SConstruct b/bsp/lpc176x/SConstruct
index fddbc18a1c..9e9229fa3a 100644
--- a/bsp/lpc176x/SConstruct
+++ b/bsp/lpc176x/SConstruct
@@ -2,7 +2,10 @@ import os
 import sys
 import rtconfig
 
-RTT_ROOT = os.path.normpath(os.getcwd() + '/../..')
+if os.getenv('RTT_ROOT'):
+    RTT_ROOT = os.getenv('RTT_ROOT')
+else:
+    RTT_ROOT = os.path.normpath(os.getcwd() + '/../..')
 sys.path = sys.path + [os.path.join(RTT_ROOT, 'tools')]
 from building import *
 
diff --git a/bsp/lpc176x/board.c b/bsp/lpc176x/board.c
index a5cb4b030e..24bc828ada 100644
--- a/bsp/lpc176x/board.c
+++ b/bsp/lpc176x/board.c
@@ -63,7 +63,7 @@ void rt_hw_board_init()
 #endif
 
 	/* init systick */
-	SysTick_Config( SystemCoreClock/RT_TICK_PER_SECOND - 1);
+	SysTick_Config( SystemCoreClock/RT_TICK_PER_SECOND);
 	/* set pend exception priority */
 	NVIC_SetPriority(PendSV_IRQn, (1<<__NVIC_PRIO_BITS) - 1);
 
@@ -71,8 +71,6 @@ void rt_hw_board_init()
 	rt_hw_uart_init();
 	rt_console_set_device("uart0");
 #endif
-
-    rt_kprintf("\r\n\r\nSystemInit......\r\n");
 }
 
 /*@}*/
diff --git a/bsp/lpc176x/emac.c b/bsp/lpc176x/emac.c
index bcdb61fc60..226e5a6e09 100644
--- a/bsp/lpc176x/emac.c
+++ b/bsp/lpc176x/emac.c
@@ -218,7 +218,7 @@ static rt_err_t lpc17xx_emac_init(rt_device_t dev)
 	switch (lpc17xx_emac_device.phy_mode)
 	{
 	case EMAC_PHY_AUTO:
-		/* Use autonegotiation about the link speed. */
+		/* Use auto negotiation about the link speed. */
 		write_PHY (PHY_REG_BMCR, PHY_AUTO_NEG);
 		/* Wait to complete Auto_Negotiation. */
 		for (tout = 0; tout < 0x100000; tout++)
@@ -226,7 +226,7 @@ static rt_err_t lpc17xx_emac_init(rt_device_t dev)
 			regv = read_PHY (PHY_REG_BMSR);
 			if (regv & 0x0020)
 			{
-				/* Autonegotiation Complete. */
+				/* Auto negotiation Complete. */
 				break;
 			}
 		}
@@ -463,7 +463,7 @@ void lpc17xx_emac_hw_init(void)
 	rt_event_init(&tx_event, "tx_event", RT_IPC_FLAG_FIFO);
 	rt_sem_init(&sem_lock, "eth_lock", 1, RT_IPC_FLAG_FIFO);
 
-	/* set autonegotiation mode */
+	/* set auto negotiation mode */
 	lpc17xx_emac_device.phy_mode = EMAC_PHY_AUTO;
 
 	// OUI 00-60-37 NXP Semiconductors
diff --git a/bsp/lpc176x/rtconfig.py b/bsp/lpc176x/rtconfig.py
index 11c425ff93..563590ffb0 100644
--- a/bsp/lpc176x/rtconfig.py
+++ b/bsp/lpc176x/rtconfig.py
@@ -1,8 +1,13 @@
+import os
+
 # toolchains options
 ARCH='arm'
 CPU='cortex-m3'
 CROSS_TOOL='keil'
 
+if os.getenv('RTT_CC'):
+	CROSS_TOOL = os.getenv('RTT_CC')
+
 if  CROSS_TOOL == 'gcc':
 	PLATFORM 	= 'gcc'
 	EXEC_PATH 	= 'E:/Program Files/CodeSourcery/Sourcery G++ Lite/bin'
@@ -12,6 +17,10 @@ elif CROSS_TOOL == 'keil':
 elif CROSS_TOOL == 'iar':
 	PLATFORM 	= 'iar'
 	EXEC_PATH 	= 'E:/Program Files/IAR Systems/Embedded Workbench 6.0/arm/bin'
+
+if os.getenv('RTT_EXEC_PATH'):
+	EXEC_PATH = os.getenv('RTT_EXEC_PATH')
+
 BUILD = 'debug'
 
 if PLATFORM == 'gcc':
diff --git a/bsp/lpc176x/startup.c b/bsp/lpc176x/startup.c
index 212c84d466..86aec23495 100644
--- a/bsp/lpc176x/startup.c
+++ b/bsp/lpc176x/startup.c
@@ -132,9 +132,6 @@ int main(void)
 	/* disable interrupt first */
 	rt_hw_interrupt_disable();
 
-	/* init system setting */
-	SystemInit();
-
 	/* startup RT-Thread RTOS */
 	rtthread_startup();