Move ContinueSelfTest to a later point to save time.

firmware/lib/rollback_index.c

 /* Copyright (c) 2010-2011 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.
  *
  * Functions for querying, manipulating and locking rollback indices
  * stored in the TPM NVRAM.
  */
 
 #include "rollback_index.h"
 
@@ skipping 164 matching lines @@
 
   VBDEBUG(("TPM: SetupTPM(r%d, d%d)\n", recovery_mode, developer_mode));
 
   if (recovery_mode)
     g_rollback_recovery_mode = 1;  /* Global variables are usable in
                                     * recovery mode */
 
   RETURN_ON_FAILURE(TlclLibInit());
 
   RETURN_ON_FAILURE(TlclStartup());
-  /* Use ContinueSelfTest rather than SelfTestFull().  It enables
-   * access to the subset of TPM commands we need in the firmware, and
-   * allows the full self test to run in paralle with firmware
-   * startup.  By the time we get to the OS, self test will have
-   * completed. */
+  /* Some TPMs start the self test automatically at power on.  In that case we
+   * don't need to call ContinueSelfTest.  On some (other) TPMs,
+   * ContinueSelfTest may block.  In that case, we definitely don't want to
+   * call it here.  For TPMs in the intersection of these two sets, we're
+   * screwed.  (In other words: TPMs that require manually starting the
+   * self-test AND block will have poor performance until we split
+   * TlclSendReceive() into Send() and Receive(), and have a state machine to
+   * control setup.)
+   *
+   * This comment is likely to become obsolete in the near future, so don't
+   * trust it.  It may have not been updated.
+   */
+#ifdef TPM_MANUAL_SELFTEST
+#ifdef TPM_BLOCKING_CONTINUESELFTEST
+#warning "lousy TPM!"
+#endif
   RETURN_ON_FAILURE(TlclContinueSelfTest());
+#endif
   result = TlclAssertPhysicalPresence();
   if (result != 0) {
     /* It is possible that the TPM was delivered with the physical presence
      * command disabled.  This tries enabling it, then tries asserting PP
      * again.
      */
     RETURN_ON_FAILURE(TlclPhysicalPresenceCMDEnable());
     RETURN_ON_FAILURE(TlclAssertPhysicalPresence());
   }
 
@@ skipping 206 matching lines @@
 
 uint32_t RollbackKernelLock(void) {
   if (g_rollback_recovery_mode) {
     return TPM_SUCCESS;
   } else {
     return TlclLockPhysicalPresence();
   }
 }
 
 #endif // DISABLE_ROLLBACK_TPM