Cr50: Add stub to implement native NV storage

This adds the unimplemented NVMem.c functions from libtpm2 to the
local repo. It depends on the libtpm2 CL that removes NVMem.c
from the embedded library.

BUG=chrome-os-partner:44745
BRANCH=none
CQ-DEPEND=CL:296476
TEST=manual

  sudo emerge tpm2 tpm2-simulator

  cd src/platform/ec
  make buildall

Change-Id: If7f0d5d71b3e68626cf2c80ea3335ebb9bc9902f
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/296525
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>

1 files changed, 168 insertions, 0 deletions

diff --git a/board/cr50/tpm2/NVMem.c b/board/cr50/tpm2/NVMem.c
new file mode 100644
index 0000000000..6ec0031454
--- /dev/null
+++ b/board/cr50/tpm2/NVMem.c
@@ -0,0 +1,168 @@
+/* Copyright 2015 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.
+ *
+ * The function prototypes were extracted from the TCG Published
+ * Trusted Platform Module Library
+ * Part 4: Supporting Routines
+ * Family "2.0"
+ * Level 00 Revision 01.16
+ * October 30, 2014
+ */
+
+#include <string.h>
+
+#include "PlatformData.h"
+#include "TpmError.h"
+#include "assert.h"
+
+/* Local state */
+static unsigned char s_NV[NV_MEMORY_SIZE];
+static BOOL s_NvIsAvailable;
+static BOOL s_NV_unrecoverable;
+static BOOL s_NV_recoverable;
+
+/*
+ * This function is used by the simulator to set the error flags in the NV
+ * subsystem to simulate an error in the NV loading process.
+ */
+void _plat__NvErrors(BOOL recoverable, BOOL unrecoverable)
+{
+	s_NV_unrecoverable = unrecoverable;
+	s_NV_recoverable = recoverable;
+}
+
+/*
+ * This function should retrieve and verify the integrity of the saved context.
+ * On success, the NV content has been copied into local RAM for fast access.
+ *
+ * The recovery from an integrity failure depends on where the error occurred.
+ * It it was in the state that is discarded by TPM Reset, then the error is
+ * recoverable if the TPM is reset. Otherwise, the TPM must go into failure
+ * mode.
+ *
+ *     Return Value                      Meaning
+ *
+ *     0                                 if success
+ *     >0                                if receive recoverable error
+ *     <0                                if unrecoverable error
+ */
+int _plat__NVEnable(void *platParameter)
+{
+	s_NV_unrecoverable = FALSE;
+	s_NV_recoverable = FALSE;
+
+	if (s_NV_unrecoverable)
+		return -1;
+	return s_NV_recoverable;
+}
+
+void _plat__NVDisable(void)
+{
+	/* nothing yet */
+}
+
+/*
+ * Check if NV is available
+ *
+ *      Return Value                      Meaning
+ *
+ *      0                                 NV is available
+ *      1                                 NV not available due to write failure
+ *      2                                 NV not available due to rate limit
+ */
+int _plat__IsNvAvailable(void)
+{
+	if (!s_NvIsAvailable)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Read a chunk of NV memory
+ */
+void _plat__NvMemoryRead(unsigned int startOffset,
+				    unsigned int size,
+				    void *data)
+{
+	assert(startOffset + size <= NV_MEMORY_SIZE);
+	/* Copy the data from the NV image */
+	memcpy(data, &s_NV[startOffset], size);
+	return;
+}
+
+/*
+ * This function tests to see if the NV is different from the test value.
+ * Returns true if different, false if not.
+ */
+BOOL
+_plat__NvIsDifferent(unsigned int startOffset,
+		     unsigned int size,
+		     void *data)
+{
+	/* Do we need a safe memcmp here? */
+	return (memcmp(&s_NV[startOffset], data, size) != 0);
+}
+
+/*
+ * This function is used to update NV memory. The write is to a memory copy of
+ * NV. At the end of the current command, any changes are written to the actual
+ * NV memory.
+ */
+void _plat__NvMemoryWrite(unsigned int startOffset,
+			  unsigned int size,
+			  void *data)
+{
+	assert(startOffset + size <= NV_MEMORY_SIZE);
+	/* Copy the data to the NV image */
+	memcpy(&s_NV[startOffset], data, size);
+}
+
+/*
+ *      Function: Move a chunk of NV memory from source to destination,
+ *      handling overlap correctly.
+ */
+void _plat__NvMemoryMove(unsigned int sourceOffset,
+				    unsigned int destOffset,
+				    unsigned int size)
+{
+	assert(sourceOffset + size <= NV_MEMORY_SIZE);
+	assert(destOffset + size <= NV_MEMORY_SIZE);
+	/* Move data in RAM */
+	memmove(&s_NV[destOffset], &s_NV[sourceOffset], size);
+	return;
+}
+
+/*
+ * Commit the local RAM copy to NV storage.
+ *
+ *      Return Value                      Meaning
+ *
+ *      0                                 NV write success
+ *      non-0                             NV write fail
+ */
+int _plat__NvCommit(void)
+{
+	return 0;
+}
+
+/*
+ * Set the current NV state to available. This function is for testing purpose
+ * only. It is not part of the platform NV logic
+ */
+void _plat__SetNvAvail(void)
+{
+	s_NvIsAvailable = TRUE;
+	return;
+}
+
+/*
+ * Set the current NV state to unavailable. This function is for testing
+ * purpose only. It is not part of the platform NV logic
+ */
+void _plat__ClearNvAvail(void)
+{
+	s_NvIsAvailable = FALSE;
+	return;
+}