【更新】：SConscript 添加 driver 文件夹下的文件。

SConscript

@@ -10,10 +10,12 @@ src    += Glob('lib/utils/*.c')
 src    += Glob('extmod/*.c')
 src    += Glob('port/*.c')
 src    += Glob('lib/netutils/*.c')
+src    += Glob('drivers/bus/*.c')
 
 path    = [cwd + '/']
 path   += [cwd + '/port']
 path   += [cwd + '/lib/netutils']
+path   += [cwd + '/drivers/bus']
 
 LOCAL_CCFLAGS = ''