Add checksum to TPM RollbackSpace regions for FW and kernel.

BUG=chrome-os-partner:9707
TEST=manual

  make
  make runtests

You can also test it by clearing the TPM, then manually looking at the TPM
regions. In dev-mode, clear the regions and you'll see something like this:

  localhost ~ # tpmc read 1007 a
  1 0 0 0 0 0 0 0 0 0
  localhost ~ # tpmc read 1008 d
  1 4c 57 52 47 0 0 0 0 0 0 0 0
  localhost ~ #

Go back to normal mode and reboot, and you'll see something like this:

  localhost ~ # tpmc read 1007 a
  2 0 1 0 1 0 0 0 0 4f
  localhost ~ # tpmc read 1008 d
  2 4c 57 52 47 1 0 1 0 0 0 0 55
  localhost ~ #

The important things are that the first number is now 2, instead of 1, and
the last number is not zero (it's a checksum, so it'll vary depending on the
other numbers, which will themselves vary according to the firmware and
kernel versions).

Change-Id: Ia4040311c2a4b2819792549b883377c8b6b89d48
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/22856
Reviewed-by: Randall Spangler <rspangler@chromium.org>

2 files changed, 19 insertions, 4 deletions

diff --git a/firmware/lib/include/crc8.h b/firmware/lib/include/crc8.h
new file mode 100644
index 00000000..95bc9862
--- /dev/null
+++ b/firmware/lib/include/crc8.h
@@ -0,0 +1,13 @@
+/* Copyright (c) 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.
+ *
+ * Very simple 8-bit CRC function.
+ */
+#ifndef VBOOT_REFERENCE_CRC8_H_
+#define VBOOT_REFERENCE_CRC8_H_
+#include "sysincludes.h"
+
+uint8_t Crc8(const void* data, int len);
+
+#endif /* VBOOT_REFERENCE_CRC8_H_ */
diff --git a/firmware/lib/include/rollback_index.h b/firmware/lib/include/rollback_index.h
index 4d92bb71..4d847626 100644
--- a/firmware/lib/include/rollback_index.h
+++ b/firmware/lib/include/rollback_index.h
@@ -21,14 +21,15 @@
 __pragma(pack(push, 1)) /* Support packing for MSVC. */
 
 /* Kernel space - KERNEL_NV_INDEX, locked with physical presence. */
-#define ROLLBACK_SPACE_KERNEL_VERSION 1
+#define ROLLBACK_SPACE_KERNEL_VERSION 2
 #define ROLLBACK_SPACE_KERNEL_UID 0x4752574C  /* 'GRWL' */
 typedef struct RollbackSpaceKernel {
   uint8_t  struct_version;      /* Struct version, for backwards
                                  * compatibility */
   uint32_t uid;                 /* Unique ID to detect space redefinition */
   uint32_t kernel_versions;     /* Kernel versions */
-  uint32_t reserved;            /* Reserved for future expansion */
+  uint8_t reserved[3];          /* Reserved for future expansion */
+  uint8_t crc8;                 /* Checksum (v2 and later only) */
 } __attribute__((packed)) RollbackSpaceKernel;
 
 
@@ -41,13 +42,14 @@ typedef struct RollbackSpaceKernel {
  * from the backup copy. */
 #define FLAG_KERNEL_SPACE_USE_BACKUP 0x02
 
-#define ROLLBACK_SPACE_FIRMWARE_VERSION 1
+#define ROLLBACK_SPACE_FIRMWARE_VERSION 2
 /* Firmware space - FIRMWARE_NV_INDEX, locked with global lock. */
 typedef struct RollbackSpaceFirmware {
   uint8_t  struct_version;  /* Struct version, for backwards compatibility */
   uint8_t  flags;           /* Flags (see FLAG_* above) */
   uint32_t fw_versions;     /* Firmware versions */
-  uint32_t reserved;            /* Reserved for future expansion */
+  uint8_t reserved[3];      /* Reserved for future expansion */
+  uint8_t crc8;             /* Checksum (v2 and later only) */
 } __attribute__((packed)) RollbackSpaceFirmware;
 
 __pragma(pack(pop)) /* Support packing for MSVC. */