firmware/2lib/2nvstorage.c - mirrors/cros/chromiumos/platform/vboot_reference - Git at Google

 /* 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 "2sysincludes.h"
 #include "2common.h"
 #include "2crc8.h"
 #include "2misc.h"
 #include "2nvstorage.h"
 #include "2nvstorage_fields.h"

 static void vb2_nv_regen_crc(struct vb2_context *ctx)
 {
 	ctx->nvdata[VB2_NV_OFFS_CRC] = vb2_crc8(ctx->nvdata, VB2_NV_OFFS_CRC);
 	ctx->flags |= VB2_CONTEXT_NVDATA_CHANGED;
 }

 /**
  * Check the CRC of the non-volatile storage context.
  *
  * Use this if reading from non-volatile storage may be flaky, and you want to
  * retry reading it several times.
  *
  * This may be called before vb2_context_init().
  *
  * @param ctx		Context pointer
  * @return VB2_SUCCESS, or non-zero error code if error.
  */
 int vb2_nv_check_crc(const struct vb2_context *ctx)
 {
 	const uint8_t *p = ctx->nvdata;

 	/* Check header */
 	if (VB2_NV_HEADER_SIGNATURE !=
 	    (p[VB2_NV_OFFS_HEADER] & VB2_NV_HEADER_MASK))
 		return VB2_ERROR_NV_HEADER;

 	/* Check CRC */
 	if (vb2_crc8(p, VB2_NV_OFFS_CRC) != p[VB2_NV_OFFS_CRC])
 		return VB2_ERROR_NV_CRC;

 	return VB2_SUCCESS;
 }

 void vb2_nv_init(struct vb2_context *ctx)
 {
 	struct vb2_shared_data *sd = vb2_get_sd(ctx);
 	uint8_t *p = ctx->nvdata;

 	/* Check data for consistency */
 	if (vb2_nv_check_crc(ctx) != VB2_SUCCESS) {
 		/* Data is inconsistent (bad CRC or header); reset defaults */
 		memset(p, 0, VB2_NVDATA_SIZE);
 		p[VB2_NV_OFFS_HEADER] = (VB2_NV_HEADER_SIGNATURE |
 					 VB2_NV_HEADER_FW_SETTINGS_RESET |
 					 VB2_NV_HEADER_KERNEL_SETTINGS_RESET);

 		/* Regenerate CRC */
 		vb2_nv_regen_crc(ctx);

 		/* Set status flag */
 		sd->status |= VB2_SD_STATUS_NV_REINIT;
 		/* TODO: unit test for status flag being set */
 	}

 	sd->status |= VB2_SD_STATUS_NV_INIT;
 }

 /* Macro for vb2_nv_get() single-bit settings to reduce duplicate code. */
 #define GETBIT(offs, mask) (p[offs] & mask ? 1 : 0)

 uint32_t vb2_nv_get(struct vb2_context *ctx, enum vb2_nv_param param)
 {
 	const uint8_t *p = ctx->nvdata;

 	/*
 	 * TODO: We could reduce the binary size for this code by #ifdef'ing
 	 * out the params not used by firmware verification.
 	 */
 	switch (param) {
 	case VB2_NV_FIRMWARE_SETTINGS_RESET:
 		return GETBIT(VB2_NV_OFFS_HEADER,
 			      VB2_NV_HEADER_FW_SETTINGS_RESET);

 	case VB2_NV_KERNEL_SETTINGS_RESET:
 		return GETBIT(VB2_NV_OFFS_HEADER,
 			      VB2_NV_HEADER_KERNEL_SETTINGS_RESET);

 	case VB2_NV_DEBUG_RESET_MODE:
 		return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DEBUG_RESET);

 	case VB2_NV_TRY_NEXT:
 		return GETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRY_NEXT);

 	case VB2_NV_TRY_COUNT:
 		return p[VB2_NV_OFFS_BOOT] & VB2_NV_BOOT_TRY_COUNT_MASK;

 	case VB2_NV_FW_TRIED:
 		return GETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRIED);

 	case VB2_NV_FW_RESULT:
 		return p[VB2_NV_OFFS_BOOT2] & VB2_NV_BOOT2_RESULT_MASK;

 	case VB2_NV_FW_PREV_TRIED:
 		return GETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_PREV_TRIED);

 	case VB2_NV_FW_PREV_RESULT:
 		return (p[VB2_NV_OFFS_BOOT2] & VB2_NV_BOOT2_PREV_RESULT_MASK)
 			>> VB2_NV_BOOT2_PREV_RESULT_SHIFT;

 	case VB2_NV_RECOVERY_REQUEST:
 		return p[VB2_NV_OFFS_RECOVERY];

 	case VB2_NV_RECOVERY_SUBCODE:
 		return p[VB2_NV_OFFS_RECOVERY_SUBCODE];

 	case VB2_NV_LOCALIZATION_INDEX:
 		return p[VB2_NV_OFFS_LOCALIZATION];

 	case VB2_NV_KERNEL_FIELD:
 		return (p[VB2_NV_OFFS_KERNEL]
 			| (p[VB2_NV_OFFS_KERNEL + 1] << 8)
 			| (p[VB2_NV_OFFS_KERNEL + 2] << 16)
 			| (p[VB2_NV_OFFS_KERNEL + 3] << 24));

 	case VB2_NV_DEV_BOOT_USB:
 		return GETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_USB);

 	case VB2_NV_DEV_BOOT_LEGACY:
 		return GETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_LEGACY);

 	case VB2_NV_DEV_BOOT_SIGNED_ONLY:
 		return GETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_SIGNED_ONLY);

 	case VB2_NV_DEV_BOOT_FASTBOOT_FULL_CAP:
 		return GETBIT(VB2_NV_OFFS_DEV,
 			      VB2_NV_DEV_FLAG_FASTBOOT_FULL_CAP);

 	case VB2_NV_DISABLE_DEV_REQUEST:
 		return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DISABLE_DEV);

 	case VB2_NV_OPROM_NEEDED:
 		return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_OPROM_NEEDED);

 	case VB2_NV_BACKUP_NVRAM_REQUEST:
 		return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_BACKUP_NVRAM);

 	case VB2_NV_CLEAR_TPM_OWNER_REQUEST:
 		return GETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_REQUEST);

 	case VB2_NV_CLEAR_TPM_OWNER_DONE:
 		return GETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_DONE);

 	case VB2_NV_REQ_WIPEOUT:
 		return GETBIT(VB2_NV_OFFS_HEADER , VB2_NV_HEADER_WIPEOUT);

 	case VB2_NV_FASTBOOT_UNLOCK_IN_FW:
 		return GETBIT(VB2_NV_OFFS_FASTBOOT,
 			      VB2_NV_FASTBOOT_FLAG_UNLOCK_IN_FW);
 	}

 	/*
 	 * Put default return outside the switch() instead of in default:, so
 	 * that adding a new param will cause a compiler warning.
 	 */
 	return 0;
 }

 #undef GETBIT

 /* Macro for vb2_nv_set() single-bit settings to reduce duplicate code. */
 #define SETBIT(offs, mask)					\
 	{ if (value) p[offs] |= mask; else p[offs] &= ~mask; }

 void vb2_nv_set(struct vb2_context *ctx,
 		enum vb2_nv_param param,
 		uint32_t value)
 {
 	uint8_t *p = ctx->nvdata;

 	/* If not changing the value, don't regenerate the CRC. */
 	if (vb2_nv_get(ctx, param) == value)
 		return;

 	/*
 	 * TODO: We could reduce the binary size for this code by #ifdef'ing
 	 * out the params not used by firmware verification.
 	 */
 	switch (param) {
 	case VB2_NV_FIRMWARE_SETTINGS_RESET:
 		SETBIT(VB2_NV_OFFS_HEADER, VB2_NV_HEADER_FW_SETTINGS_RESET);
 		break;

 	case VB2_NV_KERNEL_SETTINGS_RESET:
 		SETBIT(VB2_NV_OFFS_HEADER, VB2_NV_HEADER_KERNEL_SETTINGS_RESET);
 		break;

 	case VB2_NV_DEBUG_RESET_MODE:
 		SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DEBUG_RESET);
 		break;

 	case VB2_NV_TRY_NEXT:
 		SETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRY_NEXT);
 		break;

 	case VB2_NV_TRY_COUNT:
 		/* Clip to valid range. */
 		if (value > VB2_NV_BOOT_TRY_COUNT_MASK)
 			value = VB2_NV_BOOT_TRY_COUNT_MASK;

 		p[VB2_NV_OFFS_BOOT] &= ~VB2_NV_BOOT_TRY_COUNT_MASK;
 		p[VB2_NV_OFFS_BOOT] |= (uint8_t)value;
 		break;

 	case VB2_NV_FW_TRIED:
 		SETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRIED);
 		break;

 	case VB2_NV_FW_RESULT:
 		/* Map out of range values to unknown */
 		if (value > VB2_NV_BOOT2_RESULT_MASK)
 			value = VB2_FW_RESULT_UNKNOWN;

 		p[VB2_NV_OFFS_BOOT2] &= ~VB2_NV_BOOT2_RESULT_MASK;
 		p[VB2_NV_OFFS_BOOT2] |= (uint8_t)value;
 		break;

 	case VB2_NV_FW_PREV_TRIED:
 		SETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_PREV_TRIED);
 		break;

 	case VB2_NV_FW_PREV_RESULT:
 		/* Map out of range values to unknown */
 		if (value > VB2_NV_BOOT2_RESULT_MASK)
 			value = VB2_FW_RESULT_UNKNOWN;

 		p[VB2_NV_OFFS_BOOT2] &= ~VB2_NV_BOOT2_PREV_RESULT_MASK;
 		p[VB2_NV_OFFS_BOOT2] |=
 			(uint8_t)(value << VB2_NV_BOOT2_PREV_RESULT_SHIFT);
 		break;

 	case VB2_NV_RECOVERY_REQUEST:
 		/*
 		 * Map values outside the valid range to the legacy reason,
 		 * since we can't determine if we're called from kernel or user
 		 * mode.
 		 */
 		if (value > 0xff)
 			value = VB2_RECOVERY_LEGACY;
 		p[VB2_NV_OFFS_RECOVERY] = (uint8_t)value;
 		break;

 	case VB2_NV_RECOVERY_SUBCODE:
 		p[VB2_NV_OFFS_RECOVERY_SUBCODE] = (uint8_t)value;
 		break;

 	case VB2_NV_LOCALIZATION_INDEX:
 		/* Map values outside the valid range to the default index. */
 		if (value > 0xFF)
 			value = 0;
 		p[VB2_NV_OFFS_LOCALIZATION] = (uint8_t)value;
 		break;

 	case VB2_NV_KERNEL_FIELD:
 		p[VB2_NV_OFFS_KERNEL] = (uint8_t)(value);
 		p[VB2_NV_OFFS_KERNEL + 1] = (uint8_t)(value >> 8);
 		p[VB2_NV_OFFS_KERNEL + 2] = (uint8_t)(value >> 16);
 		p[VB2_NV_OFFS_KERNEL + 3] = (uint8_t)(value >> 24);
 		break;

 	case VB2_NV_DEV_BOOT_USB:
 		SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_USB);
 		break;

 	case VB2_NV_DEV_BOOT_LEGACY:
 		SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_LEGACY);
 		break;

 	case VB2_NV_DEV_BOOT_SIGNED_ONLY:
 		SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_SIGNED_ONLY);
 		break;

 	case VB2_NV_DEV_BOOT_FASTBOOT_FULL_CAP:
 		SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_FASTBOOT_FULL_CAP);
 		break;

 	case VB2_NV_DISABLE_DEV_REQUEST:
 		SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DISABLE_DEV);
 		break;

 	case VB2_NV_OPROM_NEEDED:
 		SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_OPROM_NEEDED);
 		break;

 	case VB2_NV_BACKUP_NVRAM_REQUEST:
 		SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_BACKUP_NVRAM);
 		break;

 	case VB2_NV_CLEAR_TPM_OWNER_REQUEST:
 		SETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_REQUEST);
 		break;

 	case VB2_NV_CLEAR_TPM_OWNER_DONE:
 		SETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_DONE);
 		break;

 	case VB2_NV_REQ_WIPEOUT:
 		SETBIT(VB2_NV_OFFS_HEADER , VB2_NV_HEADER_WIPEOUT);
 		break;

 	case VB2_NV_FASTBOOT_UNLOCK_IN_FW:
 		SETBIT(VB2_NV_OFFS_FASTBOOT, VB2_NV_FASTBOOT_FLAG_UNLOCK_IN_FW);
 		break;

 	}

 	/*
 	 * Note there is no default case.  This causes a compiler warning if
 	 * a new param is added to the enum without adding support here.
 	 */

 	/* Need to regenerate CRC, since the value changed. */
 	vb2_nv_regen_crc(ctx);
 }

 #undef SETBIT
	/* 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 "2sysincludes.h"
	#include "2common.h"
	#include "2crc8.h"
	#include "2misc.h"
	#include "2nvstorage.h"
	#include "2nvstorage_fields.h"

	static void vb2_nv_regen_crc(struct vb2_context *ctx)
	{
	ctx->nvdata[VB2_NV_OFFS_CRC] = vb2_crc8(ctx->nvdata, VB2_NV_OFFS_CRC);
	ctx->flags \|= VB2_CONTEXT_NVDATA_CHANGED;
	}

	/**
	* Check the CRC of the non-volatile storage context.
	*
	* Use this if reading from non-volatile storage may be flaky, and you want to
	* retry reading it several times.
	*
	* This may be called before vb2_context_init().
	*
	* @param ctx Context pointer
	* @return VB2_SUCCESS, or non-zero error code if error.
	*/
	int vb2_nv_check_crc(const struct vb2_context *ctx)
	{
	const uint8_t *p = ctx->nvdata;

	/* Check header */
	if (VB2_NV_HEADER_SIGNATURE !=
	(p[VB2_NV_OFFS_HEADER] & VB2_NV_HEADER_MASK))
	return VB2_ERROR_NV_HEADER;

	/* Check CRC */
	if (vb2_crc8(p, VB2_NV_OFFS_CRC) != p[VB2_NV_OFFS_CRC])
	return VB2_ERROR_NV_CRC;

	return VB2_SUCCESS;
	}

	void vb2_nv_init(struct vb2_context *ctx)
	{
	struct vb2_shared_data *sd = vb2_get_sd(ctx);
	uint8_t *p = ctx->nvdata;

	/* Check data for consistency */
	if (vb2_nv_check_crc(ctx) != VB2_SUCCESS) {
	/* Data is inconsistent (bad CRC or header); reset defaults */
	memset(p, 0, VB2_NVDATA_SIZE);
	p[VB2_NV_OFFS_HEADER] = (VB2_NV_HEADER_SIGNATURE \|
	VB2_NV_HEADER_FW_SETTINGS_RESET \|
	VB2_NV_HEADER_KERNEL_SETTINGS_RESET);

	/* Regenerate CRC */
	vb2_nv_regen_crc(ctx);

	/* Set status flag */
	sd->status \|= VB2_SD_STATUS_NV_REINIT;
	/* TODO: unit test for status flag being set */
	}

	sd->status \|= VB2_SD_STATUS_NV_INIT;
	}

	/* Macro for vb2_nv_get() single-bit settings to reduce duplicate code. */
	#define GETBIT(offs, mask) (p[offs] & mask ? 1 : 0)

	uint32_t vb2_nv_get(struct vb2_context *ctx, enum vb2_nv_param param)
	{
	const uint8_t *p = ctx->nvdata;

	/*
	* TODO: We could reduce the binary size for this code by #ifdef'ing
	* out the params not used by firmware verification.
	*/
	switch (param) {
	case VB2_NV_FIRMWARE_SETTINGS_RESET:
	return GETBIT(VB2_NV_OFFS_HEADER,
	VB2_NV_HEADER_FW_SETTINGS_RESET);

	case VB2_NV_KERNEL_SETTINGS_RESET:
	return GETBIT(VB2_NV_OFFS_HEADER,
	VB2_NV_HEADER_KERNEL_SETTINGS_RESET);

	case VB2_NV_DEBUG_RESET_MODE:
	return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DEBUG_RESET);

	case VB2_NV_TRY_NEXT:
	return GETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRY_NEXT);

	case VB2_NV_TRY_COUNT:
	return p[VB2_NV_OFFS_BOOT] & VB2_NV_BOOT_TRY_COUNT_MASK;

	case VB2_NV_FW_TRIED:
	return GETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRIED);

	case VB2_NV_FW_RESULT:
	return p[VB2_NV_OFFS_BOOT2] & VB2_NV_BOOT2_RESULT_MASK;

	case VB2_NV_FW_PREV_TRIED:
	return GETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_PREV_TRIED);

	case VB2_NV_FW_PREV_RESULT:
	return (p[VB2_NV_OFFS_BOOT2] & VB2_NV_BOOT2_PREV_RESULT_MASK)
	>> VB2_NV_BOOT2_PREV_RESULT_SHIFT;

	case VB2_NV_RECOVERY_REQUEST:
	return p[VB2_NV_OFFS_RECOVERY];

	case VB2_NV_RECOVERY_SUBCODE:
	return p[VB2_NV_OFFS_RECOVERY_SUBCODE];

	case VB2_NV_LOCALIZATION_INDEX:
	return p[VB2_NV_OFFS_LOCALIZATION];

	case VB2_NV_KERNEL_FIELD:
	return (p[VB2_NV_OFFS_KERNEL]
	\| (p[VB2_NV_OFFS_KERNEL + 1] << 8)
	\| (p[VB2_NV_OFFS_KERNEL + 2] << 16)
	\| (p[VB2_NV_OFFS_KERNEL + 3] << 24));

	case VB2_NV_DEV_BOOT_USB:
	return GETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_USB);

	case VB2_NV_DEV_BOOT_LEGACY:
	return GETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_LEGACY);

	case VB2_NV_DEV_BOOT_SIGNED_ONLY:
	return GETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_SIGNED_ONLY);

	case VB2_NV_DEV_BOOT_FASTBOOT_FULL_CAP:
	return GETBIT(VB2_NV_OFFS_DEV,
	VB2_NV_DEV_FLAG_FASTBOOT_FULL_CAP);

	case VB2_NV_DISABLE_DEV_REQUEST:
	return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DISABLE_DEV);

	case VB2_NV_OPROM_NEEDED:
	return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_OPROM_NEEDED);

	case VB2_NV_BACKUP_NVRAM_REQUEST:
	return GETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_BACKUP_NVRAM);

	case VB2_NV_CLEAR_TPM_OWNER_REQUEST:
	return GETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_REQUEST);

	case VB2_NV_CLEAR_TPM_OWNER_DONE:
	return GETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_DONE);

	case VB2_NV_REQ_WIPEOUT:
	return GETBIT(VB2_NV_OFFS_HEADER , VB2_NV_HEADER_WIPEOUT);

	case VB2_NV_FASTBOOT_UNLOCK_IN_FW:
	return GETBIT(VB2_NV_OFFS_FASTBOOT,
	VB2_NV_FASTBOOT_FLAG_UNLOCK_IN_FW);
	}

	/*
	* Put default return outside the switch() instead of in default:, so
	* that adding a new param will cause a compiler warning.
	*/
	return 0;
	}

	#undef GETBIT

	/* Macro for vb2_nv_set() single-bit settings to reduce duplicate code. */
	#define SETBIT(offs, mask) \
	{ if (value) p[offs] \|= mask; else p[offs] &= ~mask; }

	void vb2_nv_set(struct vb2_context *ctx,
	enum vb2_nv_param param,
	uint32_t value)
	{
	uint8_t *p = ctx->nvdata;

	/* If not changing the value, don't regenerate the CRC. */
	if (vb2_nv_get(ctx, param) == value)
	return;

	/*
	* TODO: We could reduce the binary size for this code by #ifdef'ing
	* out the params not used by firmware verification.
	*/
	switch (param) {
	case VB2_NV_FIRMWARE_SETTINGS_RESET:
	SETBIT(VB2_NV_OFFS_HEADER, VB2_NV_HEADER_FW_SETTINGS_RESET);
	break;

	case VB2_NV_KERNEL_SETTINGS_RESET:
	SETBIT(VB2_NV_OFFS_HEADER, VB2_NV_HEADER_KERNEL_SETTINGS_RESET);
	break;

	case VB2_NV_DEBUG_RESET_MODE:
	SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DEBUG_RESET);
	break;

	case VB2_NV_TRY_NEXT:
	SETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRY_NEXT);
	break;

	case VB2_NV_TRY_COUNT:
	/* Clip to valid range. */
	if (value > VB2_NV_BOOT_TRY_COUNT_MASK)
	value = VB2_NV_BOOT_TRY_COUNT_MASK;

	p[VB2_NV_OFFS_BOOT] &= ~VB2_NV_BOOT_TRY_COUNT_MASK;
	p[VB2_NV_OFFS_BOOT] \|= (uint8_t)value;
	break;

	case VB2_NV_FW_TRIED:
	SETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_TRIED);
	break;

	case VB2_NV_FW_RESULT:
	/* Map out of range values to unknown */
	if (value > VB2_NV_BOOT2_RESULT_MASK)
	value = VB2_FW_RESULT_UNKNOWN;

	p[VB2_NV_OFFS_BOOT2] &= ~VB2_NV_BOOT2_RESULT_MASK;
	p[VB2_NV_OFFS_BOOT2] \|= (uint8_t)value;
	break;

	case VB2_NV_FW_PREV_TRIED:
	SETBIT(VB2_NV_OFFS_BOOT2, VB2_NV_BOOT2_PREV_TRIED);
	break;

	case VB2_NV_FW_PREV_RESULT:
	/* Map out of range values to unknown */
	if (value > VB2_NV_BOOT2_RESULT_MASK)
	value = VB2_FW_RESULT_UNKNOWN;

	p[VB2_NV_OFFS_BOOT2] &= ~VB2_NV_BOOT2_PREV_RESULT_MASK;
	p[VB2_NV_OFFS_BOOT2] \|=
	(uint8_t)(value << VB2_NV_BOOT2_PREV_RESULT_SHIFT);
	break;

	case VB2_NV_RECOVERY_REQUEST:
	/*
	* Map values outside the valid range to the legacy reason,
	* since we can't determine if we're called from kernel or user
	* mode.
	*/
	if (value > 0xff)
	value = VB2_RECOVERY_LEGACY;
	p[VB2_NV_OFFS_RECOVERY] = (uint8_t)value;
	break;

	case VB2_NV_RECOVERY_SUBCODE:
	p[VB2_NV_OFFS_RECOVERY_SUBCODE] = (uint8_t)value;
	break;

	case VB2_NV_LOCALIZATION_INDEX:
	/* Map values outside the valid range to the default index. */
	if (value > 0xFF)
	value = 0;
	p[VB2_NV_OFFS_LOCALIZATION] = (uint8_t)value;
	break;

	case VB2_NV_KERNEL_FIELD:
	p[VB2_NV_OFFS_KERNEL] = (uint8_t)(value);
	p[VB2_NV_OFFS_KERNEL + 1] = (uint8_t)(value >> 8);
	p[VB2_NV_OFFS_KERNEL + 2] = (uint8_t)(value >> 16);
	p[VB2_NV_OFFS_KERNEL + 3] = (uint8_t)(value >> 24);
	break;

	case VB2_NV_DEV_BOOT_USB:
	SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_USB);
	break;

	case VB2_NV_DEV_BOOT_LEGACY:
	SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_LEGACY);
	break;

	case VB2_NV_DEV_BOOT_SIGNED_ONLY:
	SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_SIGNED_ONLY);
	break;

	case VB2_NV_DEV_BOOT_FASTBOOT_FULL_CAP:
	SETBIT(VB2_NV_OFFS_DEV, VB2_NV_DEV_FLAG_FASTBOOT_FULL_CAP);
	break;

	case VB2_NV_DISABLE_DEV_REQUEST:
	SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_DISABLE_DEV);
	break;

	case VB2_NV_OPROM_NEEDED:
	SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_OPROM_NEEDED);
	break;

	case VB2_NV_BACKUP_NVRAM_REQUEST:
	SETBIT(VB2_NV_OFFS_BOOT, VB2_NV_BOOT_BACKUP_NVRAM);
	break;

	case VB2_NV_CLEAR_TPM_OWNER_REQUEST:
	SETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_REQUEST);
	break;

	case VB2_NV_CLEAR_TPM_OWNER_DONE:
	SETBIT(VB2_NV_OFFS_TPM, VB2_NV_TPM_CLEAR_OWNER_DONE);
	break;

	case VB2_NV_REQ_WIPEOUT:
	SETBIT(VB2_NV_OFFS_HEADER , VB2_NV_HEADER_WIPEOUT);
	break;

	case VB2_NV_FASTBOOT_UNLOCK_IN_FW:
	SETBIT(VB2_NV_OFFS_FASTBOOT, VB2_NV_FASTBOOT_FLAG_UNLOCK_IN_FW);
	break;

	}

	/*
	* Note there is no default case. This causes a compiler warning if
	* a new param is added to the enum without adding support here.
	*/

	/* Need to regenerate CRC, since the value changed. */
	vb2_nv_regen_crc(ctx);
	}

	#undef SETBIT