/* Copyright (c) 2014 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.
|
*/
|
|
/* Non-volatile storage routines.
|
*/
|
#include "sysincludes.h"
|
|
#include "crc8.h"
|
#include "utility.h"
|
#include "vboot_common.h"
|
#include "vboot_nvstorage.h"
|
#include "rollback_index.h"
|
|
/* These are the fields of the nvram that we want to back up. */
|
static const VbNvParam backup_params[] = {
|
VBNV_KERNEL_FIELD,
|
VBNV_LOCALIZATION_INDEX,
|
VBNV_DEV_BOOT_USB,
|
VBNV_DEV_BOOT_LEGACY,
|
VBNV_DEV_BOOT_SIGNED_ONLY,
|
};
|
|
/* We can't back things up if there isn't enough storage. */
|
BUILD_ASSERT(VBNV_BLOCK_SIZE <= BACKUP_NV_SIZE);
|
|
int RestoreNvFromBackup(VbNvContext *vnc)
|
{
|
VbNvContext bvnc;
|
uint32_t value;
|
int i;
|
|
VBDEBUG(("TPM: %s()\n", __func__));
|
|
if (TPM_SUCCESS != RollbackBackupRead(bvnc.raw))
|
return 1;
|
|
VbNvSetup(&bvnc);
|
if (bvnc.regenerate_crc) {
|
VBDEBUG(("TPM: Oops, backup is no good.\n"));
|
return 1;
|
}
|
|
for (i = 0; i < ARRAY_SIZE(backup_params); i++) {
|
VbNvGet(&bvnc, backup_params[i], &value);
|
VbNvSet(vnc, backup_params[i], value);
|
}
|
|
/* VbNvTeardown(&bvnc); is not needed. We're done with it. */
|
return 0;
|
}
|
|
int SaveNvToBackup(VbNvContext *vnc)
|
{
|
VbNvContext bvnc;
|
uint32_t value;
|
int i;
|
|
VBDEBUG(("TPM: %s()\n", __func__));
|
|
/* Read it first. No point in writing the same data. */
|
if (TPM_SUCCESS != RollbackBackupRead(bvnc.raw))
|
return 1;
|
|
VbNvSetup(&bvnc);
|
VBDEBUG(("TPM: existing backup is %s\n",
|
bvnc.regenerate_crc ? "bad" : "good"));
|
|
for (i = 0; i < ARRAY_SIZE(backup_params); i++) {
|
VbNvGet(vnc, backup_params[i], &value);
|
VbNvSet(&bvnc, backup_params[i], value);
|
}
|
|
VbNvTeardown(&bvnc);
|
|
if (!bvnc.raw_changed) {
|
VBDEBUG(("TPM: Nothing's changed, not writing backup\n"));
|
/* Clear the request flag, since we're happy. */
|
VbNvSet(vnc, VBNV_BACKUP_NVRAM_REQUEST, 0);
|
return 0;
|
}
|
|
if (TPM_SUCCESS == RollbackBackupWrite(bvnc.raw)) {
|
/* Clear the request flag if we wrote successfully too */
|
VbNvSet(vnc, VBNV_BACKUP_NVRAM_REQUEST, 0);
|
return 0;
|
}
|
|
VBDEBUG(("TPM: Sorry, couldn't write backup.\n"));
|
return 1;
|
}
|
