Add test to demonstrate Mambo with Buildroot

Let's add test to demonstrate OS state Mambo
boottest with Buildroot environment.

Refer this blog for more details,
https://sathnaga86.com/2019/11/19/guide-to-run-test-on-power9-from-laptop-using-simulator.html

Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>

Author: Satheesh Rajendran

testcases/OpTestMamboBuildRoot.py

@@ -0,0 +1,92 @@
+#!/usr/bin/env python3
+# OpenPOWER Automated Test Project
+#
+# Contributors Listed Below - COPYRIGHT 2017
+# [+] International Business Machines Corp.
+#
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# permissions and limitations under the License.
+#
+# POWER9 Functional Simulator User Guide
+# http://public.dhe.ibm.com/software/server/powerfuncsim/p9/docs/P9funcsim_ug_v1.0_pub.pdf
+#
+# POWER9 Functional Simulator Command Reference Guide
+# http://public.dhe.ibm.com/software/server/powerfuncsim/p9/docs/P9funcsim_cr_v1.0_pub.pdf
+
+'''
+Test for Mambo Sim with BuildRoot Env
+Usage:
+Sample config looks like:
+$ cat mambo.cfg
+[op-test]
+bmc_type=mambo
+mambo_binary=./mambo/p9/systemsim-p9-release/run/p9/run_cmdline
+flash_skiboot=./mambo/p9/skiboot/skiboot.lid
+flash_kernel=./mambo/linux/vmlinux
+flash_initramfs=./mambo/mamboinit.img
+host_user=root
+host_password=
+
+$ ./op-test -c mambo.cfg --run testcases.OpTestMamboBuildRoot.OpTestMamboBuildRoot
+
+Note:
+for mambo/power-simulator binary/package can be obtained from
+ftp://public.dhe.ibm.com/software/server/powerfuncsim/
+mamboinit.img is a image obtained from compiling https://github.com/open-power/buildroot
+skiboot.lid is obtained by compiling https://github.com/open-power/skiboot
+checkout readme of respective respositories for how to compile.
+'''
+
+import unittest
+
+import OpTestConfiguration
+from common.OpTestSystem import OpSystemState
+import common.OpTestMambo as OpTestMambo
+
+import OpTestLogger
+log = OpTestLogger.optest_logger_glob.get_logger(__name__)
+
+
+class OpTestMamboBuildRoot(unittest.TestCase):
+    '''
+    Mambo Build Root test
+    '''
+
+    def setUp(self):
+        conf = OpTestConfiguration.conf
+        self.ipmi = conf.ipmi()
+        self.system = conf.system()
+        self.host = conf.host()
+        self.system.goto_state(OpSystemState.OS)
+        self.prompt = self.system.util.build_prompt()
+        self.c = self.system.console
+        self.pty = self.c.get_console()
+        if not isinstance(self.c, OpTestMambo.MamboConsole):
+            raise unittest.SkipTest(
+                "Must be running Mambo to perform this test")
+
+    def runTest(self):
+        # need to first perform run_command initially
+        # which sets up the pexpect prompt for subsequent run_command(s)
+
+        # mambo echos twice so turn off
+        # this stays persistent even after switching context
+        # from target OS to mambo and back
+        self.c.run_command('stty -echo')
+
+        uname_output = self.c.run_command('uname -a')
+        log.debug("uname = {}".format(uname_output))
+        cpuinfo_output = self.c.run_command('cat /proc/cpuinfo')
+        log.debug("cpuinfo = {}".format(cpuinfo_output))
+        int_output = self.c.run_command('cat /proc/interrupts')
+        log.debug("interrupts = {}".format(int_output))