bsp: add basic configure files for abstract-machine

bsp/abstract-machine/SConstruct

@@ -0,0 +1,31 @@
+import os
+import sys
+import rtconfig
+
+from rtconfig import RTT_ROOT
+
+sys.path = sys.path + [os.path.join(RTT_ROOT, 'tools')]
+from building import *
+
+TARGET = 'rtthread.' + rtconfig.TARGET_EXT
+
+DefaultEnvironment(tools=[])
+env = Environment(tools = ['mingw'],
+    AS = rtconfig.AS, ASFLAGS = rtconfig.AFLAGS,
+    CC = rtconfig.CC, CCFLAGS = rtconfig.CFLAGS,
+    CXX = rtconfig.CXX, CXXFLAGS = rtconfig.CXXFLAGS,
+    AR = rtconfig.AR, ARFLAGS = '-rc',
+    LINK = rtconfig.LINK, LINKFLAGS = rtconfig.LFLAGS)
+env.PrependENVPath('PATH', rtconfig.EXEC_PATH)
+env['ASCOM'] = env['ASPPCOM']
+
+Export('RTT_ROOT')
+Export('rtconfig')
+rtconfig.CPU='virt64'
+rtconfig.ARCH='risc-v'
+
+# prepare building environment
+objs = PrepareBuilding(env, RTT_ROOT, has_libcpu = True)
+
+# make a building
+DoBuilding(TARGET, objs)