创建，添加sdram

rt-thread/components/vbus/SConscript

@@ -0,0 +1,23 @@
+# RT-Thread building script for component
+
+import SCons, os
+from building import *
+
+group = []
+if not GetDepend(['RT_USING_VBUS']):
+    Return('group')
+
+cwd = GetCurrentDir()
+src = Glob('*.c')
+
+for c, f in [['RT_USING_VBUS_RFS', 'utilities/rfs.c'],
+             ['RT_USING_VBUS_RSHELL', 'utilities/rshell.c'],
+             ]:
+    if GetDepend(c):
+        src += Glob(f)
+
+CPPPATH = [cwd, os.path.join(cwd, 'share_hdr')]
+
+group = DefineGroup('VBus', src, depend = ['RT_USING_VBUS'], CPPPATH = CPPPATH)
+
+Return('group')