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/* Copyright (c) 2013 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.
*
* High-level firmware wrapper API - entry points for init, firmware selection
*/
#include "sysincludes.h"
#include "gbb_access.h"
#include "gbb_header.h"
#include "load_firmware_fw.h"
#include "rollback_index.h"
#include "tpm_bootmode.h"
#include "utility.h"
#include "vboot_api.h"
#include "vboot_common.h"
#include "vboot_nvstorage.h"
VbError_t VbSelectFirmware(VbCommonParams *cparams,
VbSelectFirmwareParams *fparams)
{
VbSharedDataHeader *shared =
(VbSharedDataHeader *)cparams->shared_data_blob;
VbNvContext vnc;
VbError_t retval = VBERROR_UNKNOWN; /* Default to error */
int is_rec = (shared->recovery_reason ? 1 : 0);
int is_dev = (shared->flags & VBSD_BOOT_DEV_SWITCH_ON ? 1 : 0);
uint32_t tpm_status = 0;
cparams->gbb = NULL;
cparams->bmp = NULL;
/* Start timer */
shared->timer_vb_select_firmware_enter = VbExGetTimer();
/* Load NV storage */
VbExNvStorageRead(vnc.raw);
VbNvSetup(&vnc);
if (is_rec) {
/*
* Recovery is requested; go straight to recovery without
* checking the RW firmware.
*/
VBDEBUG(("VbSelectFirmware() detected recovery request\n"));
/* Best effort to read the GBB */
cparams->gbb = VbExMalloc(sizeof(*cparams->gbb));
retval = VbGbbReadHeader_static(cparams, cparams->gbb);
if (VBERROR_SUCCESS != retval) {
VBDEBUG(("Can't read GBB. Continuing anyway...\n"));
VbExFree(cparams->gbb);
cparams->gbb = NULL;
}
/* Go directly to recovery mode */
fparams->selected_firmware = VB_SELECT_FIRMWARE_RECOVERY;
} else {
cparams->gbb = VbExMalloc(sizeof(*cparams->gbb));
retval = VbGbbReadHeader_static(cparams, cparams->gbb);
if (VBERROR_SUCCESS != retval)
goto VbSelectFirmware_exit;
/* Chain to LoadFirmware() */
retval = LoadFirmware(cparams, fparams, &vnc);
/* Exit if we failed to find an acceptable firmware */
if (VBERROR_SUCCESS != retval)
goto VbSelectFirmware_exit;
/* Translate the selected firmware path */
if (shared->flags & VBSD_LF_USE_RO_NORMAL) {
/* Request the read-only normal/dev code path */
fparams->selected_firmware =
VB_SELECT_FIRMWARE_READONLY;
} else if (0 == shared->firmware_index)
fparams->selected_firmware = VB_SELECT_FIRMWARE_A;
else {
fparams->selected_firmware = VB_SELECT_FIRMWARE_B;
}
/* Update TPM if necessary */
if (shared->fw_version_tpm_start < shared->fw_version_tpm) {
tpm_status =
RollbackFirmwareWrite(shared->fw_version_tpm);
if (0 != tpm_status) {
VBDEBUG(("Can't write FW version to TPM.\n"));
VbNvSet(&vnc, VBNV_RECOVERY_REQUEST,
VBNV_RECOVERY_RO_TPM_W_ERROR);
retval = VBERROR_TPM_WRITE_FIRMWARE;
goto VbSelectFirmware_exit;
}
}
/* Lock firmware versions in TPM */
tpm_status = RollbackFirmwareLock();
if (0 != tpm_status) {
VBDEBUG(("Unable to lock firmware version in TPM.\n"));
VbNvSet(&vnc, VBNV_RECOVERY_REQUEST,
VBNV_RECOVERY_RO_TPM_L_ERROR);
retval = VBERROR_TPM_LOCK_FIRMWARE;
goto VbSelectFirmware_exit;
}
}
/*
* At this point, we have a good idea of how we are going to
* boot. Update the TPM with this state information.
*/
tpm_status = SetTPMBootModeState(is_dev, is_rec,
shared->fw_keyblock_flags,
cparams->gbb);
if (0 != tpm_status) {
VBDEBUG(("Can't update the TPM with boot mode information.\n"));
if (!is_rec) {
VbNvSet(&vnc, VBNV_RECOVERY_REQUEST,
VBNV_RECOVERY_RO_TPM_U_ERROR);
retval = VBERROR_TPM_SET_BOOT_MODE_STATE;
goto VbSelectFirmware_exit;
}
}
/* Success! */
retval = VBERROR_SUCCESS;
VbSelectFirmware_exit:
if (cparams->gbb) {
VbExFree(cparams->gbb);
cparams->gbb = NULL;
}
/* Save NV storage */
VbNvTeardown(&vnc);
if (vnc.raw_changed)
VbExNvStorageWrite(vnc.raw);
/* Stop timer */
shared->timer_vb_select_firmware_exit = VbExGetTimer();
/* Should always have a known error code */
VbAssert(VBERROR_UNKNOWN != retval);
return retval;
}
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