| # Copyright (c) 2012 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import logging |
| import os |
| import re |
| |
| from autotest_lib.client.bin import test, utils |
| from autotest_lib.client.common_lib import error |
| |
| class firmware_LockedME(test.test): |
| # Needed by autotest |
| version = 1 |
| |
| # Temporary file to read BIOS image into. We run in a tempdir anyway, so it |
| # doesn't need a path. |
| BIOS_FILE = 'bios.bin' |
| |
| def flashrom(self, ignore_status=False, args=()): |
| """Run flashrom, expect it to work. Fail if it doesn't""" |
| extra = ['-p', 'host'] + list(args) |
| return utils.run('flashrom', ignore_status=ignore_status, args=extra) |
| |
| def has_ME(self): |
| """See if we can detect an ME. |
| FREG* is printed only when HSFS_FDV is set, which means the descriptor |
| table is valid. If we're running a BIOS without a valid descriptor this |
| step will fail. Unfortunately, we don't know of a simple and reliable |
| way to identify systems that have ME hardware. |
| """ |
| logging.info('See if we have an ME...') |
| r = self.flashrom(args=('-V',)) |
| return r.stdout.find("FREG0") >= 0 |
| |
| def try_to_rewrite(self, sectname): |
| """If we can modify the ME section, restore it and raise an error.""" |
| logging.info('Try to write section %s...', sectname) |
| size = os.stat(sectname).st_size |
| utils.run('dd', args=('if=/dev/urandom', 'of=newdata', |
| 'count=1', 'bs=%d' % (size))) |
| r = self.flashrom(args=('-w', self.BIOS_FILE, |
| '-i' , '%s:newdata' % (sectname), |
| '--fast-verify'), |
| ignore_status=True) |
| if not r.exit_status: |
| logging.info('Oops, it worked! Put it back...') |
| self.flashrom(args=('-w', self.BIOS_FILE, |
| '-i', '%s:%s' % (sectname, sectname), |
| '--fast-verify'), |
| ignore_status=True) |
| raise error.TestFail('%s is writable, ME is unlocked' % sectname) |
| |
| def run_once(self, expect_me_present=True): |
| """Fail unless the ME is locked. |
| |
| @param expect_me_present: False means the system has no ME. |
| """ |
| |
| # See if the system even has an ME, and whether we expected that. |
| if self.has_ME(): |
| if not expect_me_present: |
| raise error.TestFail('We expected no ME, but found one anyway') |
| else: |
| if expect_me_present: |
| raise error.TestNAError("No ME found. That's probably wrong.") |
| else: |
| logging.info('We expected no ME and we have no ME, so pass.') |
| return |
| |
| # See if coreboot told us that the ME is still in Manufacturing Mode. |
| # It shouldn't be. We have to look only at the last thing it reports |
| # because it reports the values twice and the first one isn't always |
| # reliable. |
| logging.info('Check for Manufacturing Mode...') |
| last = None |
| with open('/sys/firmware/log') as infile: |
| for line in infile: |
| if re.search('ME: Manufacturing Mode', line): |
| last = line |
| if last is not None and last.find("YES") >= 0: |
| raise error.TestFail("The ME is still in Manufacturing Mode") |
| |
| # Get the bios image and extract the ME components |
| logging.info('Pull the ME components from the BIOS...') |
| self.flashrom(args=('-r', self.BIOS_FILE)) |
| utils.run('dump_fmap', args=('-x', self.BIOS_FILE, 'SI_ME', 'SI_DESC')) |
| |
| # flashrom should have read the SI_ME section as all 0xff's. If not, |
| # the ME is not locked. |
| logging.info('SI_ME should be all 0xff...') |
| with open('SI_ME', 'rb') as f: |
| for c in f.read(): |
| if c != chr(0xff): |
| raise error.TestFail("SI_ME was readable by flashrom") |
| |
| # So far, so good, but we need to be certain. Rather than parse what |
| # flashrom tells us about the ME-related registers, we'll just try to |
| # change the ME components. We shouldn't be able to. |
| self.try_to_rewrite('SI_DESC') |
| self.try_to_rewrite('SI_ME') |
| |
| # Okay, that's about all we can try. Looks like it's locked. |