lpc43xx: fix the default RTT_ROOT in SConstruct

bsp/lpc43xx/M0/SConstruct

@@ -5,7 +5,7 @@ import rtconfig
 if os.getenv('RTT_ROOT'):
     RTT_ROOT = os.getenv('RTT_ROOT')
 else:
-    RTT_ROOT = os.path.join(Dir('#').get_abspath(), '..', '..', 'rt-thread')
+    RTT_ROOT = os.path.join(Dir('#').get_abspath(), '..', '..', '..')
 
 sys.path = sys.path + [os.path.join(RTT_ROOT, 'tools')]
 from building import *

bsp/lpc43xx/M4/SConstruct

@@ -5,12 +5,12 @@ import rtconfig
 if os.getenv('RTT_ROOT'):
     RTT_ROOT = os.getenv('RTT_ROOT')
 else:
-    RTT_ROOT = os.path.join(Dir('#').get_abspath(), '..', '..', 'rt-thread')
+    RTT_ROOT = os.path.join(Dir('#').get_abspath(), '..', '..', '..')
 
 sys.path = sys.path + [os.path.join(RTT_ROOT, 'tools')]
 from building import *
 
-TARGET = 'rtthread-lpc40xx.' + rtconfig.TARGET_EXT
+TARGET = 'build/rtthread_lpc43xx.' + rtconfig.TARGET_EXT
 
 env = Environment(tools = ['mingw'],
     AS = rtconfig.AS, ASFLAGS = rtconfig.AFLAGS,
@@ -25,5 +25,22 @@ Export('rtconfig')
 # prepare building environment
 objs = PrepareBuilding(env, RTT_ROOT, has_libcpu=False)
 
+if rtconfig.CROSS_TOOL == 'gcc':
+    print 'build M0 code first'
+    if sys.platform.startswith('linux'):
+        ocwd = os.getcwdu()
+        os.chdir('../M0')
+        res = os.system('scons')
+        if res:
+            print 'build M0 exit with code %d\n' % res
+            sys.exit(res)
+        os.chdir(ocwd)
+    else:
+        # assume Windows.
+        ocwd = os.getcwdu()
+        os.chdir('..\M0')
+        os.system('scons.bat')
+        os.chdir(ocwd)
+
 # do building 
 DoBuilding(TARGET, objs)