vboot: Separate vboot from chromeos

VBOOT_VERIFY_FIRMWARE should be independent of CHROMEOS. This allows use
of verified boot library without having to stick to CHROMEOS.

BUG=chrome-os-partner:55639

Change-Id: Ia2c328712caedd230ab295b8a613e3c1ed1532d9
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/15867
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

20 files changed, 2742 insertions, 0 deletions

diff --git a/src/vboot/Kconfig b/src/vboot/Kconfig
new file mode 100644
index 0000000000..6f9e3b9b16
--- /dev/null
+++ b/src/vboot/Kconfig
@@ -0,0 +1,143 @@
+## This file is part of the coreboot project.
+##
+## Copyright (C) 2014 The ChromiumOS Authors.  All rights reserved.
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; version 2 of the License.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+
+config VBOOT_VBNV_OFFSET
+	hex
+	default 0x26
+	depends on PC80_SYSTEM
+	help
+	  CMOS offset for VbNv data. This value must match cmos.layout
+	  in the mainboard directory, minus 14 bytes for the RTC.
+
+config VBOOT_VBNV_CMOS
+	bool "Vboot non-volatile storage in CMOS."
+	default n
+	help
+	  VBNV is stored in CMOS
+
+config VBOOT_VBNV_CMOS_BACKUP_TO_FLASH
+	bool "Back up Vboot non-volatile storage from CMOS to flash."
+	default n
+	depends on VBOOT_VBNV_CMOS
+	help
+	  Vboot non-volatile storage data will be backed up from CMOS to flash
+	  and restored from flash if the CMOS is invalid due to power loss.
+
+config VBOOT_VBNV_EC
+	bool "Vboot non-volatile storage in EC."
+	default n
+	help
+	  VBNV is stored in EC
+
+config VBOOT_VBNV_FLASH
+	def_bool n
+	help
+	  VBNV is stored in flash storage
+
+config VBOOT_STARTS_IN_BOOTBLOCK
+	bool "Vboot starts verifying in bootblock"
+	default n
+	depends on VBOOT
+	help
+	  Firmware verification happens during or at the end of bootblock.
+
+config VBOOT_STARTS_IN_ROMSTAGE
+	bool "Vboot starts verifying in romstage"
+	default n
+	depends on VBOOT && !VBOOT_STARTS_IN_BOOTBLOCK
+	help
+	  Firmware verification happens during or at the end of romstage.
+
+config VBOOT_MOCK_SECDATA
+	bool "Mock secdata for firmware verification"
+	default n
+	depends on VBOOT
+	help
+	  Enabling VBOOT_MOCK_SECDATA will mock secdata for the firmware
+	  verification to avoid access to a secdata storage (typically TPM).
+	  All operations for a secdata storage will be successful. This option
+	  can be used during development when a TPM is not present or broken.
+	  THIS SHOULD NOT BE LEFT ON FOR PRODUCTION DEVICES.
+
+config VBOOT_DISABLE_DEV_ON_RECOVERY
+	bool "Disable dev mode on recovery requests"
+	default n
+	depends on VBOOT
+	help
+	  When this option is enabled, the Chrome OS device leaves the
+	  developer mode as soon as recovery request is detected. This is
+	  handy on embedded devices with limited input capabilities.
+
+config SEPARATE_VERSTAGE
+	bool "Vboot verification is built into a separate stage"
+	default n
+	depends on VBOOT
+
+config RETURN_FROM_VERSTAGE
+	bool "The separate verification stage returns to its caller"
+	default n
+	depends on SEPARATE_VERSTAGE
+	help
+	  If this is set, the verstage returns back to the calling stage instead
+	  of exiting to the succeeding stage so that the verstage space can be
+	  reused by the succeeding stage. This is useful if a ram space is too
+	  small to fit both the verstage and the succeeding stage.
+
+config CHIPSET_PROVIDES_VERSTAGE_MAIN_SYMBOL
+	bool "The chipset provides the main() entry point for verstage"
+	default n
+	depends on SEPARATE_VERSTAGE
+	help
+	  The chipset code provides their own main() entry point.
+
+config VBOOT_DYNAMIC_WORK_BUFFER
+	bool "Vboot's work buffer is dynamically allocated."
+	default y if ARCH_ROMSTAGE_X86_32 && !SEPARATE_VERSTAGE
+	default n
+	depends on VBOOT
+	help
+	  This option is used when there isn't enough pre-main memory
+	  ram to allocate the vboot work buffer. That means vboot verification
+	  is after memory init and requires main memory to back the work
+	  buffer.
+
+config VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT
+	bool
+	default n
+	depends on VBOOT
+	help
+	  This option ensures that the recovery request is not lost because of
+	  reboots caused after vboot verification is run. e.g. reboots caused by
+	  FSP components on Intel platforms.
+
+config VBOOT_OPROM_MATTERS
+	bool "Video option ROM matters (= can skip display init)"
+	default n
+	depends on VBOOT
+	help
+	  Set this option to indicate to vboot that this platform will skip its
+	  display initialization on a normal (non-recovery, non-developer) boot.
+	  Vboot calls this "oprom matters" because on x86 devices this
+	  traditionally meant that the video option ROM will not be loaded, but
+	  it works functionally the same for other platforms that can skip their
+	  native display initialization code instead.
+
+config VBOOT
+	bool "Verify firmware with vboot."
+	default n
+	depends on HAVE_HARD_RESET
+	help
+	  Enabling VBOOT will use vboot to verify the components of the firmware
+	  (stages, payload, etc).
+
diff --git a/src/vboot/Makefile.inc b/src/vboot/Makefile.inc
new file mode 100644
index 0000000000..c43af72d04
--- /dev/null
+++ b/src/vboot/Makefile.inc
@@ -0,0 +1,143 @@
+##
+## This file is part of the coreboot project.
+##
+## Copyright (C) 2014 The ChromiumOS Authors.  All rights reserved.
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; version 2 of the License.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+
+libverstage-generic-ccopts += -D__PRE_RAM__ -D__VERSTAGE__
+verstage-generic-ccopts += -D__PRE_RAM__ -D__VERSTAGE__
+
+bootblock-y += vbnv.c
+verstage-y += vbnv.c
+romstage-y += vbnv.c
+ramstage-y += vbnv.c
+
+bootblock-$(CONFIG_VBOOT_VBNV_CMOS) += vbnv_cmos.c
+verstage-$(CONFIG_VBOOT_VBNV_CMOS) += vbnv_cmos.c
+romstage-$(CONFIG_VBOOT_VBNV_CMOS) += vbnv_cmos.c
+ramstage-$(CONFIG_VBOOT_VBNV_CMOS) += vbnv_cmos.c
+
+bootblock-$(CONFIG_VBOOT_VBNV_CMOS_BACKUP_TO_FLASH) += vbnv_flash.c
+verstage-$(CONFIG_VBOOT_VBNV_CMOS_BACKUP_TO_FLASH) += vbnv_flash.c
+romstage-$(CONFIG_VBOOT_VBNV_CMOS_BACKUP_TO_FLASH) += vbnv_flash.c
+ramstage-$(CONFIG_VBOOT_VBNV_CMOS_BACKUP_TO_FLASH) += vbnv_flash.c
+
+bootblock-$(CONFIG_VBOOT_VBNV_EC) += vbnv_ec.c
+verstage-$(CONFIG_VBOOT_VBNV_EC) += vbnv_ec.c
+romstage-$(CONFIG_VBOOT_VBNV_EC) += vbnv_ec.c
+ramstage-$(CONFIG_VBOOT_VBNV_EC) += vbnv_ec.c
+
+bootblock-$(CONFIG_VBOOT_VBNV_FLASH) += vbnv_flash.c
+verstage-$(CONFIG_VBOOT_VBNV_FLASH) += vbnv_flash.c
+romstage-$(CONFIG_VBOOT_VBNV_FLASH) += vbnv_flash.c
+ramstage-$(CONFIG_VBOOT_VBNV_FLASH) += vbnv_flash.c
+
+bootblock-y += vboot_loader.c
+romstage-y += vboot_loader.c
+ramstage-y += vboot_loader.c
+verstage-y += vboot_loader.c
+postcar-y += vboot_loader.c
+
+bootblock-y += vboot_common.c
+verstage-y += vboot_common.c
+romstage-y += vboot_common.c
+ramstage-y += vboot_common.c
+postcar-y += vboot_common.c
+
+bootblock-y += recovery.c
+romstage-y += recovery.c
+ramstage-y += recovery.c
+verstage-y += recovery.c
+postcar-y += recovery.c
+
+bootblock-y += common.c
+libverstage-y += vboot_logic.c
+verstage-y += common.c
+verstage-y += verstage.c
+ifeq (${CONFIG_VBOOT_MOCK_SECDATA},y)
+libverstage-y += secdata_mock.c
+else
+libverstage-y += secdata_tpm.c
+endif
+romstage-y += vboot_handoff.c common.c
+
+ramstage-y += common.c
+postcar-y += common.c
+
+ifeq ($(CONFIG_SEPARATE_VERSTAGE),y)
+VB_FIRMWARE_ARCH := $(ARCHDIR-$(ARCH-verstage-y))
+else
+ifeq ($(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK),y)
+VB_FIRMWARE_ARCH := $(ARCHDIR-$(ARCH-bootblock-y))
+else
+VB_FIRMWARE_ARCH := $(ARCHDIR-$(ARCH-romstage-y))
+endif
+endif # CONFIG_SEPARATE_VERSTAGE
+
+VB2_LIB = $(obj)/external/vboot_reference/vboot_fw20.a
+VBOOT_CFLAGS += $(patsubst -I%,-I$(top)/%, $(filter-out -I$(obj), $(filter-out -include $(src)/include/kconfig.h, $(CPPFLAGS_libverstage))))
+VBOOT_CFLAGS += $(CFLAGS_libverstage)
+VBOOT_CFLAGS += $(libverstage-c-ccopts)
+VBOOT_CFLAGS += -I$(abspath $(obj)) -include $(top)/src/include/kconfig.h -Wno-missing-prototypes
+VBOOT_CFLAGS += -DVBOOT_DEBUG
+
+$(VB2_LIB): $(obj)/config.h
+	@printf "    MAKE       $(subst $(obj)/,,$(@))\n"
+	$(Q)FIRMWARE_ARCH=$(VB_FIRMWARE_ARCH) \
+	CC="$(CC_verstage)" \
+	CFLAGS="$(VBOOT_CFLAGS)" VBOOT2="y" \
+	$(MAKE) -C $(VBOOT_SOURCE) \
+		BUILD=$(abspath $(dir $(VB2_LIB))) \
+		V=$(V) \
+		fwlib20
+
+libverstage-srcs += $(VB2_LIB)
+
+ifeq ($(CONFIG_SEPARATE_VERSTAGE),y)
+cbfs-files-$(CONFIG_SEPARATE_VERSTAGE) += $(CONFIG_CBFS_PREFIX)/verstage
+$(CONFIG_CBFS_PREFIX)/verstage-file := $(objcbfs)/verstage.elf
+$(CONFIG_CBFS_PREFIX)/verstage-type := stage
+$(CONFIG_CBFS_PREFIX)/verstage-compression := $(CBFS_PRERAM_COMPRESS_FLAG)
+
+ifeq ($(CONFIG_ARCH_VERSTAGE_X86_32)$(CONFIG_ARCH_VERSTAGE_X86_64),y)
+$(CONFIG_CBFS_PREFIX)/verstage-options := -a 64 -S ".car.data"
+
+# If CAR does not support execution of code, verstage on x86 is expected to be
+# xip.
+ifneq ($(CONFIG_NO_XIP_EARLY_STAGES),y)
+$(CONFIG_CBFS_PREFIX)/verstage-options += --xip
+endif
+
+endif
+
+else
+ifeq ($(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK),y)
+bootblock-srcs += $(objgenerated)/libverstage.a
+else
+romstage-srcs += $(objgenerated)/libverstage.a
+endif
+endif # CONFIG_SEPARATE_VERSTAGE
+
+# Define a list of files that need to be in RO only.
+# All other files will be installed into RO and RW regions
+# Use $(sort) to cut down on extra spaces that would be translated to commas
+regions-for-file = $(subst $(spc),$(comma),$(sort \
+	$(if $(filter \
+		$(if $(filter y,$(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK)),, \
+			%/romstage) \
+		mts \
+		%/verstage \
+		locales \
+		locale_%.bin \
+		font.bin \
+		vbgfx.bin \
+		,$(1)),COREBOOT,COREBOOT FW_MAIN_A FW_MAIN_B)))
diff --git a/src/vboot/common.c b/src/vboot/common.c
new file mode 100644
index 0000000000..3fa96577fd
--- /dev/null
+++ b/src/vboot/common.c
@@ -0,0 +1,182 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <assert.h>
+#include <cbfs.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <reset.h>
+#include <string.h>
+#include <vb2_api.h>
+#include <vboot/misc.h>
+#include <vboot/symbols.h>
+#include <vboot/vboot_common.h>
+
+struct selected_region {
+	uint32_t offset;
+	uint32_t size;
+};
+
+/*
+ * this is placed at the start of the vboot work buffer. selected_region is used
+ * for the verstage to return the location of the selected slot. buffer is used
+ * by the vboot2 core. Keep the struct cpu architecture agnostic as it crosses
+ * stage boundaries.
+ */
+struct vb2_working_data {
+	struct selected_region selected_region;
+	/* offset of the buffer from the start of this struct */
+	uint32_t buffer_offset;
+	uint32_t buffer_size;
+};
+
+static const size_t vb_work_buf_size = 16 * KiB;
+
+static struct vb2_working_data * const vboot_get_working_data(void)
+{
+	if (IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER))
+		/* cbmem_add() does a cbmem_find() first. */
+		return cbmem_add(CBMEM_ID_VBOOT_WORKBUF, vb_work_buf_size);
+	else
+		return (struct vb2_working_data *)_vboot2_work;
+}
+
+static size_t vb2_working_data_size(void)
+{
+	if (IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER))
+		return vb_work_buf_size;
+	else
+		return _vboot2_work_size;
+}
+
+static struct selected_region *vb2_selected_region(void)
+{
+	struct selected_region *sel_reg = NULL;
+
+	/* Ramstage and postcar always uses cbmem as a source of truth. */
+	if (ENV_RAMSTAGE || ENV_POSTCAR)
+		sel_reg = cbmem_find(CBMEM_ID_VBOOT_SEL_REG);
+	else if (ENV_ROMSTAGE) {
+		/* Try cbmem first. Fall back on working data if not found. */
+		sel_reg = cbmem_find(CBMEM_ID_VBOOT_SEL_REG);
+
+		if (sel_reg == NULL) {
+			struct vb2_working_data *wd = vboot_get_working_data();
+			sel_reg = &wd->selected_region;
+		}
+	} else {
+		/* Stages such as bootblock and verstage use working data. */
+		struct vb2_working_data *wd = vboot_get_working_data();
+		sel_reg = &wd->selected_region;
+	}
+
+	return sel_reg;
+}
+
+void vb2_init_work_context(struct vb2_context *ctx)
+{
+	struct vb2_working_data *wd;
+	size_t work_size;
+
+	/* First initialize the working data region. */
+	work_size = vb2_working_data_size();
+	wd = vboot_get_working_data();
+	memset(wd, 0, work_size);
+
+	/*
+	 * vboot prefers 16-byte alignment. This takes away 16 bytes
+	 * from the VBOOT2_WORK region, but the vboot devs said that's okay.
+	 */
+	wd->buffer_offset = ALIGN_UP(sizeof(*wd), 16);
+	wd->buffer_size = work_size - wd->buffer_offset;
+
+	/* Initialize the vb2_context. */
+	memset(ctx, 0, sizeof(*ctx));
+	ctx->workbuf = (void *)vb2_get_shared_data();
+	ctx->workbuf_size = wd->buffer_size;
+
+}
+
+struct vb2_shared_data *vb2_get_shared_data(void)
+{
+	struct vb2_working_data *wd = vboot_get_working_data();
+	return (void *)((uintptr_t)wd + wd->buffer_offset);
+}
+
+int vb2_get_selected_region(struct region *region)
+{
+	const struct selected_region *reg = vb2_selected_region();
+
+	if (reg == NULL)
+		return -1;
+
+	if (reg->offset == 0 && reg->size == 0)
+		return -1;
+
+	region->offset = reg->offset;
+	region->size = reg->size;
+
+	return 0;
+}
+
+void vb2_set_selected_region(const struct region *region)
+{
+	struct selected_region *reg = vb2_selected_region();
+
+	assert(reg != NULL);
+
+	reg->offset = region_offset(region);
+	reg->size = region_sz(region);
+}
+
+int vb2_is_slot_selected(void)
+{
+	const struct selected_region *reg = vb2_selected_region();
+
+	assert(reg != NULL);
+
+	return reg->size > 0;
+}
+
+void vb2_store_selected_region(void)
+{
+	const struct vb2_working_data *wd;
+	struct selected_region *sel_reg;
+
+	/* Always use the working data in this path since it's the object
+	 * which has the result.. */
+	wd = vboot_get_working_data();
+
+	sel_reg = cbmem_add(CBMEM_ID_VBOOT_SEL_REG, sizeof(*sel_reg));
+
+	assert(sel_reg != NULL);
+
+	sel_reg->offset = wd->selected_region.offset;
+	sel_reg->size = wd->selected_region.size;
+}
+
+/*
+ * For platforms that employ VBOOT_DYNAMIC_WORK_BUFFER, the vboot
+ * verification doesn't happen until after cbmem is brought online.
+ * Therefore, the selected region contents would not be initialized
+ * so don't automatically add results when cbmem comes online.
+ */
+#if !IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER)
+static void vb2_store_selected_region_cbmem(int unused)
+{
+	vb2_store_selected_region();
+}
+ROMSTAGE_CBMEM_INIT_HOOK(vb2_store_selected_region_cbmem)
+#endif
diff --git a/src/vboot/misc.h b/src/vboot/misc.h
new file mode 100644
index 0000000000..dc94720ea5
--- /dev/null
+++ b/src/vboot/misc.h
@@ -0,0 +1,40 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __VBOOT_MISC_H__
+#define __VBOOT_MISC_H__
+
+#include <vboot/vboot_common.h>
+
+struct vb2_context;
+struct vb2_shared_data;
+
+void vboot_fill_handoff(void);
+
+void vb2_init_work_context(struct vb2_context *ctx);
+struct vb2_shared_data *vb2_get_shared_data(void);
+
+/* Returns 0 on success. < 0 on failure. */
+int vb2_get_selected_region(struct region *region);
+void vb2_set_selected_region(const struct region *region);
+int vb2_is_slot_selected(void);
+int vb2_logic_executed(void);
+
+/* Store the selected region in cbmem for later use. */
+void vb2_store_selected_region(void);
+
+void vb2_save_recovery_reason_vbnv(void);
+
+#endif /* __VBOOT_MISC_H__ */
diff --git a/src/vboot/recovery.c b/src/vboot/recovery.c
new file mode 100644
index 0000000000..6e6eb0e159
--- /dev/null
+++ b/src/vboot/recovery.c
@@ -0,0 +1,152 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <assert.h>
+#include <bootmode.h>
+#include <bootstate.h>
+#include <rules.h>
+#include <string.h>
+#include <vb2_api.h>
+#include <vboot/misc.h>
+#include <vboot/vbnv.h>
+#include <vboot/vboot_common.h>
+
+static int vb2_get_recovery_reason_shared_data(void)
+{
+	/* Shared data does not exist for Ramstage and Post-CAR stage. */
+	if (ENV_RAMSTAGE || ENV_POSTCAR)
+		return 0;
+
+	struct vb2_shared_data *sd = vb2_get_shared_data();
+	assert(sd);
+	return sd->recovery_reason;
+}
+
+void vb2_save_recovery_reason_vbnv(void)
+{
+	if (!IS_ENABLED(CONFIG_VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT))
+		return;
+
+	int reason =  vb2_get_recovery_reason_shared_data();
+	if (!reason)
+		return;
+
+	set_recovery_mode_into_vbnv(reason);
+}
+
+static void vb2_clear_recovery_reason_vbnv(void *unused)
+{
+	if (!IS_ENABLED(CONFIG_VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT))
+		return;
+
+	set_recovery_mode_into_vbnv(0);
+}
+
+/*
+ * Recovery reason stored in VBNV needs to be cleared before the state of VBNV
+ * is backed-up anywhere or jumping to the payload (whichever occurs
+ * first). Currently, vbnv_cmos.c backs up VBNV on POST_DEVICE. Thus, we need to
+ * make sure that the stored recovery reason is cleared off before that
+ * happens.
+ * IMPORTANT: Any reboot occurring after BS_DEV_INIT state will cause loss of
+ * recovery reason on reboot. Until now, we have seen reboots occuring on x86
+ * only in FSP stages which run before BS_DEV_INIT.
+ */
+BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_EXIT,
+		      vb2_clear_recovery_reason_vbnv, NULL);
+
+/*
+ * Returns 0 for the stages where we know that cbmem does not come online.
+ * Even if this function returns 1 for romstage, depending upon the point in
+ * bootup, cbmem might not actually be online.
+ */
+static int cbmem_possibly_online(void)
+{
+	if (ENV_BOOTBLOCK)
+		return 0;
+
+	if (ENV_VERSTAGE && IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Returns 1 if vboot is being used and currently in a stage which might have
+ * already executed vboot verification.
+ */
+static int vboot_possibly_executed(void)
+{
+	if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK)) {
+		if (ENV_BOOTBLOCK && IS_ENABLED(CONFIG_SEPARATE_VERSTAGE))
+			return 0;
+		return 1;
+	}
+
+	if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_ROMSTAGE)) {
+		if (ENV_BOOTBLOCK)
+			return 0;
+		return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * vb2_check_recovery_request looks up different components to identify if there
+ * is a recovery request and returns appropriate reason code:
+ * 1. Checks if recovery mode is initiated by EC. If yes, returns
+ * VB2_RECOVERY_RO_MANUAL.
+ * 2. Checks if recovery request is present in VBNV and returns the code read
+ * from it.
+ * 3. Checks recovery request in handoff for stages post-cbmem.
+ * 4. For non-CBMEM stages, check if vboot verification is done and look-up
+ * selected region to identify if vboot_refence library has requested recovery
+ * path. If yes, return the reason code from shared data.
+ * 5. If nothing applies, return 0 indicating no recovery request.
+ */
+int vboot_check_recovery_request(void)
+{
+	int reason = 0;
+
+	/* EC-initiated recovery. */
+	if (get_recovery_mode_switch())
+		return VB2_RECOVERY_RO_MANUAL;
+
+	/* Recovery request in VBNV. */
+	if ((reason = get_recovery_mode_from_vbnv()) != 0)
+		return reason;
+
+	/*
+	 * Check recovery flag in vboot_handoff for stages post CBMEM coming
+	 * online. Since for some stages there is no way to know if cbmem has
+	 * already come online, try looking up handoff anyways. If it fails,
+	 * flow will fallback to looking up shared data.
+	 */
+	if (cbmem_possibly_online() &&
+	    ((reason = vboot_handoff_get_recovery_reason()) != 0))
+		return reason;
+
+	/*
+	 * For stages where CBMEM might not be online, identify if vboot
+	 * verification is already complete and no slot was selected
+	 * i.e. recovery path was requested.
+	 */
+	if (vboot_possibly_executed() && vb2_logic_executed() &&
+	    !vb2_is_slot_selected())
+		return vb2_get_recovery_reason_shared_data();
+
+	return 0;
+}
diff --git a/src/vboot/secdata_mock.c b/src/vboot/secdata_mock.c
new file mode 100644
index 0000000000..03616c1524
--- /dev/null
+++ b/src/vboot/secdata_mock.c
@@ -0,0 +1,38 @@
+/* Copyright (c) 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.
+ *
+ * Functions for querying, manipulating and locking rollback indices
+ * stored in the TPM NVRAM.
+ */
+
+#include <antirollback.h>
+#include <stdlib.h>
+#include <vb2_api.h>
+
+uint32_t tpm_extend_pcr(struct vb2_context *ctx, int pcr,
+			enum vb2_pcr_digest which_digest)
+{
+	return TPM_SUCCESS;
+}
+
+uint32_t tpm_clear_and_reenable(void)
+{
+	return TPM_SUCCESS;
+}
+
+uint32_t antirollback_read_space_firmware(struct vb2_context *ctx)
+{
+	vb2api_secdata_create(ctx);
+	return TPM_SUCCESS;
+}
+
+uint32_t antirollback_write_space_firmware(struct vb2_context *ctx)
+{
+	return TPM_SUCCESS;
+}
+
+uint32_t antirollback_lock_space_firmware()
+{
+	return TPM_SUCCESS;
+}
diff --git a/src/vboot/secdata_tpm.c b/src/vboot/secdata_tpm.c
new file mode 100644
index 0000000000..a51e5d6d55
--- /dev/null
+++ b/src/vboot/secdata_tpm.c
@@ -0,0 +1,436 @@
+/* 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.
+ *
+ * Functions for querying, manipulating and locking rollback indices
+ * stored in the TPM NVRAM.
+ */
+
+#include <antirollback.h>
+#include <stdlib.h>
+#include <string.h>
+#include <tpm_lite/tlcl.h>
+#include <vb2_api.h>
+#include <console/console.h>
+
+#ifndef offsetof
+#define offsetof(A,B) __builtin_offsetof(A,B)
+#endif
+
+#ifdef FOR_TEST
+#include <stdio.h>
+#define VBDEBUG(format, args...) printf(format, ## args)
+#else
+#include <console/console.h>
+#define VBDEBUG(format, args...) \
+	printk(BIOS_INFO, "%s():%d: " format,  __func__, __LINE__, ## args)
+#endif
+
+#define RETURN_ON_FAILURE(tpm_cmd) do {				\
+		uint32_t result_;					\
+		if ((result_ = (tpm_cmd)) != TPM_SUCCESS) {		\
+			VBDEBUG("Antirollback: %08x returned by " #tpm_cmd \
+				 "\n", (int)result_);			\
+			return result_;					\
+		}							\
+	} while (0)
+
+
+static uint32_t safe_write(uint32_t index, const void *data, uint32_t length);
+
+uint32_t tpm_extend_pcr(struct vb2_context *ctx, int pcr,
+			enum vb2_pcr_digest which_digest)
+{
+	uint8_t buffer[VB2_PCR_DIGEST_RECOMMENDED_SIZE];
+	uint32_t size = sizeof(buffer);
+	int rv;
+
+	rv = vb2api_get_pcr_digest(ctx, which_digest, buffer, &size);
+	if (rv != VB2_SUCCESS)
+		return rv;
+	if (size < TPM_PCR_DIGEST)
+		return VB2_ERROR_UNKNOWN;
+
+	return tlcl_extend(pcr, buffer, NULL);
+}
+
+static uint32_t read_space_firmware(struct vb2_context *ctx)
+{
+	int attempts = 3;
+
+	while (attempts--) {
+		RETURN_ON_FAILURE(tlcl_read(FIRMWARE_NV_INDEX, ctx->secdata,
+		                            VB2_SECDATA_SIZE));
+
+		if (vb2api_secdata_check(ctx) == VB2_SUCCESS)
+			return TPM_SUCCESS;
+
+		VBDEBUG("TPM: %s() - bad CRC\n", __func__);
+	}
+
+	VBDEBUG("TPM: %s() - too many bad CRCs, giving up\n", __func__);
+	return TPM_E_CORRUPTED_STATE;
+}
+
+static uint32_t write_secdata(uint32_t index,
+			      const uint8_t *secdata,
+			      uint32_t len)
+{
+	uint8_t sd[32];
+	uint32_t rv;
+	int attempts = 3;
+
+	if (len > sizeof(sd)) {
+		VBDEBUG("TPM: %s() - data is too large\n", __func__);
+		return TPM_E_WRITE_FAILURE;
+	}
+
+	while (attempts--) {
+		rv = safe_write(index, secdata, len);
+		/* Can't write, not gonna try again */
+		if (rv != TPM_SUCCESS)
+			return rv;
+
+		/* Read it back to be sure it got the right values. */
+		rv = tlcl_read(index, sd, len);
+		if (rv == TPM_SUCCESS && memcmp(secdata, sd, len) == 0)
+			return rv;
+
+		VBDEBUG("TPM: %s() failed. trying again\n", __func__);
+		/* Try writing it again. Maybe it was garbled on the way out. */
+	}
+
+	VBDEBUG("TPM: %s() - too many failures, giving up\n", __func__);
+
+	return TPM_E_CORRUPTED_STATE;
+}
+
+/*
+ * This is derived from rollback_index.h of vboot_reference. see struct
+ * RollbackSpaceKernel for details.
+ */
+static const uint8_t secdata_kernel[] = {
+	0x02,
+	0x4C, 0x57, 0x52, 0x47,
+	0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00,
+	0xE8,
+};
+
+#if IS_ENABLED(CONFIG_TPM2)
+
+/* Nothing special in the TPM2 path yet. */
+static uint32_t safe_write(uint32_t index, const void *data, uint32_t length)
+{
+	return tlcl_write(index, data, length);
+}
+
+static uint32_t set_firmware_space(const void *firmware_blob)
+{
+	RETURN_ON_FAILURE(tlcl_define_space(FIRMWARE_NV_INDEX,
+					    VB2_SECDATA_SIZE));
+	RETURN_ON_FAILURE(safe_write(FIRMWARE_NV_INDEX, firmware_blob,
+				     VB2_SECDATA_SIZE));
+	return TPM_SUCCESS;
+}
+
+static uint32_t set_kernel_space(const void *kernel_blob)
+{
+	RETURN_ON_FAILURE(tlcl_define_space(KERNEL_NV_INDEX,
+					    sizeof(secdata_kernel)));
+	RETURN_ON_FAILURE(safe_write(KERNEL_NV_INDEX, kernel_blob,
+				     sizeof(secdata_kernel)));
+	return TPM_SUCCESS;
+}
+
+static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
+{
+	RETURN_ON_FAILURE(tlcl_force_clear());
+	RETURN_ON_FAILURE(set_firmware_space(ctx->secdata));
+	RETURN_ON_FAILURE(set_kernel_space(secdata_kernel));
+	return TPM_SUCCESS;
+}
+
+uint32_t tpm_clear_and_reenable(void)
+{
+	VBDEBUG("TPM: Clear and re-enable\n");
+	return TPM_SUCCESS;
+}
+
+uint32_t antirollback_lock_space_firmware(void)
+{
+	return tlcl_lock_nv_write(FIRMWARE_NV_INDEX);
+}
+
+#else
+
+uint32_t tpm_clear_and_reenable(void)
+{
+	VBDEBUG("TPM: Clear and re-enable\n");
+	RETURN_ON_FAILURE(tlcl_force_clear());
+	RETURN_ON_FAILURE(tlcl_set_enable());
+	RETURN_ON_FAILURE(tlcl_set_deactivated(0));
+
+	return TPM_SUCCESS;
+}
+
+/**
+ * Like tlcl_write(), but checks for write errors due to hitting the 64-write
+ * limit and clears the TPM when that happens.  This can only happen when the
+ * TPM is unowned, so it is OK to clear it (and we really have no choice).
+ * This is not expected to happen frequently, but it could happen.
+ */
+
+static uint32_t safe_write(uint32_t index, const void *data, uint32_t length)
+{
+	uint32_t result = tlcl_write(index, data, length);
+	if (result == TPM_E_MAXNVWRITES) {
+		RETURN_ON_FAILURE(tpm_clear_and_reenable());
+		return tlcl_write(index, data, length);
+	} else {
+		return result;
+	}
+}
+
+/**
+ * Similarly to safe_write(), this ensures we don't fail a DefineSpace because
+ * we hit the TPM write limit. This is even less likely to happen than with
+ * writes because we only define spaces once at initialization, but we'd
+ * rather be paranoid about this.
+ */
+static uint32_t safe_define_space(uint32_t index, uint32_t perm, uint32_t size)
+{
+	uint32_t result = tlcl_define_space(index, perm, size);
+	if (result == TPM_E_MAXNVWRITES) {
+		RETURN_ON_FAILURE(tpm_clear_and_reenable());
+		return tlcl_define_space(index, perm, size);
+	} else {
+		return result;
+	}
+}
+
+static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
+{
+	TPM_PERMANENT_FLAGS pflags;
+	uint32_t result;
+
+	result = tlcl_get_permanent_flags(&pflags);
+	if (result != TPM_SUCCESS)
+		return result;
+
+	/*
+	 * TPM may come from the factory without physical presence finalized.
+	 * Fix if necessary.
+	 */
+	VBDEBUG("TPM: physicalPresenceLifetimeLock=%d\n",
+		 pflags.physicalPresenceLifetimeLock);
+	if (!pflags.physicalPresenceLifetimeLock) {
+		VBDEBUG("TPM: Finalizing physical presence\n");
+		RETURN_ON_FAILURE(tlcl_finalize_physical_presence());
+	}
+
+	/*
+	 * The TPM will not enforce the NV authorization restrictions until the
+	 * execution of a TPM_NV_DefineSpace with the handle of
+	 * TPM_NV_INDEX_LOCK.  Here we create that space if it doesn't already
+	 * exist. */
+	VBDEBUG("TPM: nvLocked=%d\n", pflags.nvLocked);
+	if (!pflags.nvLocked) {
+		VBDEBUG("TPM: Enabling NV locking\n");
+		RETURN_ON_FAILURE(tlcl_set_nv_locked());
+	}
+
+	/* Clear TPM owner, in case the TPM is already owned for some reason. */
+	VBDEBUG("TPM: Clearing owner\n");
+	RETURN_ON_FAILURE(tpm_clear_and_reenable());
+
+	/* Define the backup space. No need to initialize it, though. */
+	RETURN_ON_FAILURE(safe_define_space(BACKUP_NV_INDEX,
+					    TPM_NV_PER_PPWRITE,
+					    VB2_NVDATA_SIZE));
+
+	/* Define and initialize the kernel space */
+	RETURN_ON_FAILURE(safe_define_space(KERNEL_NV_INDEX,
+					    TPM_NV_PER_PPWRITE,
+					    sizeof(secdata_kernel)));
+	RETURN_ON_FAILURE(write_secdata(KERNEL_NV_INDEX,
+					secdata_kernel,
+					sizeof(secdata_kernel)));
+
+	/* Defines and sets vb2 secdata space */
+	vb2api_secdata_create(ctx);
+	RETURN_ON_FAILURE(safe_define_space(FIRMWARE_NV_INDEX,
+	                                    TPM_NV_PER_GLOBALLOCK |
+	                                    TPM_NV_PER_PPWRITE,
+	                                    VB2_SECDATA_SIZE));
+	RETURN_ON_FAILURE(write_secdata(FIRMWARE_NV_INDEX,
+					ctx->secdata,
+					VB2_SECDATA_SIZE));
+	return TPM_SUCCESS;
+}
+
+uint32_t antirollback_lock_space_firmware(void)
+{
+	return tlcl_set_global_lock();
+}
+#endif
+
+uint32_t factory_initialize_tpm(struct vb2_context *ctx)
+{
+	uint32_t result;
+
+	/* Defines and sets vb2 secdata space */
+	vb2api_secdata_create(ctx);
+
+	VBDEBUG("TPM: factory initialization\n");
+
+	/*
+	 * Do a full test.  This only happens the first time the device is
+	 * turned on in the factory, so performance is not an issue.  This is
+	 * almost certainly not necessary, but it gives us more confidence
+	 * about some code paths below that are difficult to
+	 * test---specifically the ones that set lifetime flags, and are only
+	 * executed once per physical TPM.
+	 */
+	result = tlcl_self_test_full();
+	if (result != TPM_SUCCESS)
+		return result;
+
+	result = _factory_initialize_tpm(ctx);
+	if (result != TPM_SUCCESS)
+		return result;
+
+	VBDEBUG("TPM: factory initialization successful\n");
+
+	return TPM_SUCCESS;
+}
+
+/*
+ * SetupTPM starts the TPM and establishes the root of trust for the
+ * anti-rollback mechanism.  SetupTPM can fail for three reasons.  1 A bug. 2 a
+ * TPM hardware failure. 3 An unexpected TPM state due to some attack.  In
+ * general we cannot easily distinguish the kind of failure, so our strategy is
+ * to reboot in recovery mode in all cases.  The recovery mode calls SetupTPM
+ * again, which executes (almost) the same sequence of operations.  There is a
+ * good chance that, if recovery mode was entered because of a TPM failure, the
+ * failure will repeat itself.  (In general this is impossible to guarantee
+ * because we have no way of creating the exact TPM initial state at the
+ * previous boot.)  In recovery mode, we ignore the failure and continue, thus
+ * giving the recovery kernel a chance to fix things (that's why we don't set
+ * bGlobalLock).  The choice is between a knowingly insecure device and a
+ * bricked device.
+ *
+ * As a side note, observe that we go through considerable hoops to avoid using
+ * the STCLEAR permissions for the index spaces.  We do this to avoid writing
+ * to the TPM flashram at every reboot or wake-up, because of concerns about
+ * the durability of the NVRAM.
+ */
+uint32_t setup_tpm(struct vb2_context *ctx)
+{
+	uint8_t disable;
+	uint8_t deactivated;
+	uint32_t result;
+
+	RETURN_ON_FAILURE(tlcl_lib_init());
+
+	/* Handle special init for S3 resume path */
+	if (ctx->flags & VB2_CONTEXT_S3_RESUME) {
+		result = tlcl_resume();
+		if (result == TPM_E_INVALID_POSTINIT)
+			printk(BIOS_DEBUG, "TPM: Already initialized.\n");
+		return TPM_SUCCESS;
+	}
+
+#ifdef TEGRA_SOFT_REBOOT_WORKAROUND
+	result = tlcl_startup();
+	if (result == TPM_E_INVALID_POSTINIT) {
+		/*
+		 * Some prototype hardware doesn't reset the TPM on a CPU
+		 * reset.  We do a hard reset to get around this.
+		 */
+		VBDEBUG("TPM: soft reset detected\n", result);
+		ctx->flags |= VB2_CONTEXT_SECDATA_WANTS_REBOOT;
+		return TPM_E_MUST_REBOOT;
+	} else if (result != TPM_SUCCESS) {
+		VBDEBUG("TPM: tlcl_startup returned %08x\n", result);
+		return result;
+	}
+#else
+	RETURN_ON_FAILURE(tlcl_startup());
+#endif
+
+	/*
+	 * Some TPMs start the self test automatically at power on. In that case
+	 * we don't need to call ContinueSelfTest. On some (other) TPMs,
+	 * continue_self_test may block. In that case, we definitely don't want
+	 * to call it here. For TPMs in the intersection of these two sets, we
+	 * are screwed. (In other words: TPMs that require manually starting the
+	 * self-test AND block will have poor performance until we split
+	 * tlcl_send_receive() into send() and receive(), and have a state
+	 * machine to control setup.)
+	 *
+	 * This comment is likely to become obsolete in the near future, so
+	 * don't trust it. It may have not been updated.
+	 */
+#ifdef TPM_MANUAL_SELFTEST
+#ifdef TPM_BLOCKING_CONTINUESELFTEST
+#warning "lousy TPM!"
+#endif
+	RETURN_ON_FAILURE(tlcl_continue_self_test());
+#endif
+	result = tlcl_assert_physical_presence();
+	if (result != TPM_SUCCESS) {
+		/*
+		 * It is possible that the TPM was delivered with the physical
+		 * presence command disabled.  This tries enabling it, then
+		 * tries asserting PP again.
+		 */
+		RETURN_ON_FAILURE(tlcl_physical_presence_cmd_enable());
+		RETURN_ON_FAILURE(tlcl_assert_physical_presence());
+	}
+
+	/* Check that the TPM is enabled and activated. */
+	RETURN_ON_FAILURE(tlcl_get_flags(&disable, &deactivated, NULL));
+	if (disable || deactivated) {
+		VBDEBUG("TPM: disabled (%d) or deactivated (%d). Fixing...\n",
+			disable, deactivated);
+		RETURN_ON_FAILURE(tlcl_set_enable());
+		RETURN_ON_FAILURE(tlcl_set_deactivated(0));
+		VBDEBUG("TPM: Must reboot to re-enable\n");
+		ctx->flags |= VB2_CONTEXT_SECDATA_WANTS_REBOOT;
+		return TPM_E_MUST_REBOOT;
+	}
+
+	VBDEBUG("TPM: SetupTPM() succeeded\n");
+	return TPM_SUCCESS;
+}
+
+uint32_t antirollback_read_space_firmware(struct vb2_context *ctx)
+{
+	uint32_t rv;
+
+	rv = setup_tpm(ctx);
+	if (rv)
+		return rv;
+
+	/* Read the firmware space. */
+	rv = read_space_firmware(ctx);
+	if (rv == TPM_E_BADINDEX) {
+		/*
+		 * This seems the first time we've run. Initialize the TPM.
+		 */
+		VBDEBUG("TPM: Not initialized yet.\n");
+		RETURN_ON_FAILURE(factory_initialize_tpm(ctx));
+	} else if (rv != TPM_SUCCESS) {
+		VBDEBUG("TPM: Firmware space in a bad state; giving up.\n");
+		//RETURN_ON_FAILURE(factory_initialize_tpm(ctx));
+		return TPM_E_CORRUPTED_STATE;
+	}
+
+	return TPM_SUCCESS;
+}
+
+uint32_t antirollback_write_space_firmware(struct vb2_context *ctx)
+{
+	return write_secdata(FIRMWARE_NV_INDEX, ctx->secdata, VB2_SECDATA_SIZE);
+}
diff --git a/src/vboot/symbols.h b/src/vboot/symbols.h
new file mode 100644
index 0000000000..fb3d6545f8
--- /dev/null
+++ b/src/vboot/symbols.h
@@ -0,0 +1,28 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __VBOOT_SYMBOLS_H__
+#define __VBOOT_SYMBOLS_H__
+
+extern u8 _vboot2_work[];
+extern u8 _evboot2_work[];
+#define _vboot2_work_size (_evboot2_work - _vboot2_work)
+
+/* Careful: _e<stage> and _<stage>_size only defined for the current stage! */
+extern u8 _verstage[];
+extern u8 _everstage[];
+#define _verstage_size (_everstage - _verstage)
+
+#endif /* __VBOOT_SYMBOLS_H__ */
diff --git a/src/vboot/vbnv.c b/src/vboot/vbnv.c
new file mode 100644
index 0000000000..ce6492855d
--- /dev/null
+++ b/src/vboot/vbnv.c
@@ -0,0 +1,142 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/early_variables.h>
+#include <string.h>
+#include <types.h>
+#include <vboot/vbnv.h>
+#include <vboot/vbnv_layout.h>
+
+static int vbnv_initialized CAR_GLOBAL;
+static uint8_t vbnv[VBOOT_VBNV_BLOCK_SIZE] CAR_GLOBAL;
+
+/* Wrappers for accessing the variables marked as CAR_GLOBAL. */
+static inline int is_vbnv_initialized(void)
+{
+	return car_get_var(vbnv_initialized);
+}
+
+static inline uint8_t *vbnv_data_addr(int index)
+{
+	uint8_t *vbnv_arr = car_get_var_ptr(vbnv);
+
+	return &vbnv_arr[index];
+}
+
+static inline uint8_t vbnv_data(int index)
+{
+	return *vbnv_data_addr(index);
+}
+
+/* Return CRC-8 of the data, using x^8 + x^2 + x + 1 polynomial. */
+static uint8_t crc8_vbnv(const uint8_t *data, int len)
+{
+	unsigned crc = 0;
+	int i, j;
+
+	for (j = len; j; j--, data++) {
+		crc ^= (*data << 8);
+		for (i = 8; i; i--) {
+			if (crc & 0x8000)
+				crc ^= (0x1070 << 3);
+			crc <<= 1;
+		}
+	}
+
+	return (uint8_t) (crc >> 8);
+}
+
+static void reset_vbnv(uint8_t *vbnv_copy)
+{
+	memset(vbnv_copy, 0, VBOOT_VBNV_BLOCK_SIZE);
+}
+
+/* Read VBNV data into cache. */
+static void vbnv_setup(void)
+{
+	if (!is_vbnv_initialized()) {
+		read_vbnv(vbnv_data_addr(0));
+		car_set_var(vbnv_initialized, 1);
+	}
+}
+
+/* Verify VBNV header and checksum. */
+int verify_vbnv(uint8_t *vbnv_copy)
+{
+	return (HEADER_SIGNATURE == (vbnv_copy[HEADER_OFFSET] & HEADER_MASK)) &&
+		(crc8_vbnv(vbnv_copy, CRC_OFFSET) == vbnv_copy[CRC_OFFSET]);
+}
+
+/*
+ * Read VBNV data from configured storage backend.
+ * If VBNV verification fails, reset the vbnv copy.
+ */
+void read_vbnv(uint8_t *vbnv_copy)
+{
+	if (IS_ENABLED(CONFIG_VBOOT_VBNV_CMOS))
+		read_vbnv_cmos(vbnv_copy);
+	else if (IS_ENABLED(CONFIG_VBOOT_VBNV_EC))
+		read_vbnv_ec(vbnv_copy);
+	else if (IS_ENABLED(CONFIG_VBOOT_VBNV_FLASH))
+		read_vbnv_flash(vbnv_copy);
+
+	/* Check data for consistency */
+	if (!verify_vbnv(vbnv_copy))
+		reset_vbnv(vbnv_copy);
+}
+
+/*
+ * Write VBNV data to configured storage backend.
+ * This assumes that the caller has updated the CRC already.
+ */
+void save_vbnv(const uint8_t *vbnv_copy)
+{
+	if (IS_ENABLED(CONFIG_VBOOT_VBNV_CMOS))
+		save_vbnv_cmos(vbnv_copy);
+	else if (IS_ENABLED(CONFIG_VBOOT_VBNV_EC))
+		save_vbnv_ec(vbnv_copy);
+	else if (IS_ENABLED(CONFIG_VBOOT_VBNV_FLASH))
+		save_vbnv_flash(vbnv_copy);
+
+	/* Clear initialized flag to force cached data to be updated */
+	car_set_var(vbnv_initialized, 0);
+}
+
+/* Save a recovery reason into VBNV. */
+void set_recovery_mode_into_vbnv(int recovery_reason)
+{
+	uint8_t vbnv_copy[VBOOT_VBNV_BLOCK_SIZE];
+
+	read_vbnv(vbnv_copy);
+
+	vbnv_copy[RECOVERY_OFFSET] = recovery_reason;
+	vbnv_copy[CRC_OFFSET] = crc8_vbnv(vbnv_copy, CRC_OFFSET);
+
+	save_vbnv(vbnv_copy);
+}
+
+/* Read the recovery reason from VBNV. */
+int get_recovery_mode_from_vbnv(void)
+{
+	vbnv_setup();
+	return vbnv_data(RECOVERY_OFFSET);
+}
+
+/* Read the BOOT_OPROM_NEEDED flag from VBNV. */
+int vboot_wants_oprom(void)
+{
+	vbnv_setup();
+	return (vbnv_data(BOOT_OFFSET) & BOOT_OPROM_NEEDED) ? 1 : 0;
+}
diff --git a/src/vboot/vbnv.h b/src/vboot/vbnv.h
new file mode 100644
index 0000000000..78ca8f66f3
--- /dev/null
+++ b/src/vboot/vbnv.h
@@ -0,0 +1,42 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __VBOOT_VBNV_H__
+#define __VBOOT_VBNV_H__
+
+#include <types.h>
+
+/* Generic functions */
+void read_vbnv(uint8_t *vbnv_copy);
+void save_vbnv(const uint8_t *vbnv_copy);
+int verify_vbnv(uint8_t *vbnv_copy);
+int get_recovery_mode_from_vbnv(void);
+void set_recovery_mode_into_vbnv(int recovery_reason);
+int vboot_wants_oprom(void);
+
+/* CMOS backend */
+void read_vbnv_cmos(uint8_t *vbnv_copy);
+void save_vbnv_cmos(const uint8_t *vbnv_copy);
+void init_vbnv_cmos(int rtc_fail);
+
+/* Flash backend */
+void read_vbnv_flash(uint8_t *vbnv_copy);
+void save_vbnv_flash(const uint8_t *vbnv_copy);
+
+/* EC backend */
+void read_vbnv_ec(uint8_t *vbnv_copy);
+void save_vbnv_ec(const uint8_t *vbnv_copy);
+
+#endif /* __VBOOT_VBNV_H__ */
diff --git a/src/vboot/vbnv_cmos.c b/src/vboot/vbnv_cmos.c
new file mode 100644
index 0000000000..5eda8e6e50
--- /dev/null
+++ b/src/vboot/vbnv_cmos.c
@@ -0,0 +1,79 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <bootstate.h>
+#include <console/console.h>
+#include <types.h>
+#include <pc80/mc146818rtc.h>
+#include <vboot/vbnv.h>
+#include <vboot/vbnv_layout.h>
+
+void read_vbnv_cmos(uint8_t *vbnv_copy)
+{
+	int i;
+
+	for (i = 0; i < VBOOT_VBNV_BLOCK_SIZE; i++)
+		vbnv_copy[i] = cmos_read(CONFIG_VBOOT_VBNV_OFFSET + 14 + i);
+
+	if (IS_ENABLED(CONFIG_VBOOT_VBNV_CMOS_BACKUP_TO_FLASH)) {
+		if (verify_vbnv(vbnv_copy))
+			return;
+
+		printk(BIOS_INFO, "VBNV: CMOS invalid, restoring from flash\n");
+		read_vbnv_flash(vbnv_copy);
+
+		if (verify_vbnv(vbnv_copy)) {
+			save_vbnv_cmos(vbnv_copy);
+			printk(BIOS_INFO, "VBNV: Flash backup restored\n");
+		} else {
+			printk(BIOS_INFO, "VBNV: Restore from flash failed\n");
+		}
+	}
+}
+
+void save_vbnv_cmos(const uint8_t *vbnv_copy)
+{
+	int i;
+
+	for (i = 0; i < VBOOT_VBNV_BLOCK_SIZE; i++)
+		cmos_write(vbnv_copy[i], CONFIG_VBOOT_VBNV_OFFSET + 14 + i);
+}
+
+void init_vbnv_cmos(int rtc_fail)
+{
+	uint8_t vbnv[VBOOT_VBNV_BLOCK_SIZE];
+
+	if (rtc_fail)
+		read_vbnv_cmos(vbnv);
+
+	cmos_init(rtc_fail);
+
+	if (rtc_fail)
+		save_vbnv_cmos(vbnv);
+}
+
+#if IS_ENABLED(CONFIG_VBOOT_VBNV_CMOS_BACKUP_TO_FLASH)
+static void back_up_vbnv_cmos(void *unused)
+{
+	uint8_t vbnv_cmos[VBOOT_VBNV_BLOCK_SIZE];
+
+	/* Read current VBNV from CMOS. */
+	read_vbnv_cmos(vbnv_cmos);
+
+	/* Save to flash, will only be saved if different. */
+	save_vbnv_flash(vbnv_cmos);
+}
+BOOT_STATE_INIT_ENTRY(BS_POST_DEVICE, BS_ON_EXIT, back_up_vbnv_cmos, NULL);
+#endif
diff --git a/src/vboot/vbnv_ec.c b/src/vboot/vbnv_ec.c
new file mode 100644
index 0000000000..99e2b82b1f
--- /dev/null
+++ b/src/vboot/vbnv_ec.c
@@ -0,0 +1,30 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <types.h>
+#include <ec/google/chromeec/ec.h>
+#include <vboot/vbnv.h>
+#include <vboot/vbnv_layout.h>
+
+void read_vbnv_ec(uint8_t *vbnv_copy)
+{
+	google_chromeec_vbnv_context(1, vbnv_copy, VBOOT_VBNV_BLOCK_SIZE);
+}
+
+void save_vbnv_ec(const uint8_t *vbnv_copy)
+{
+	google_chromeec_vbnv_context(0, (uint8_t *)vbnv_copy,
+				     VBOOT_VBNV_BLOCK_SIZE);
+}
diff --git a/src/vboot/vbnv_flash.c b/src/vboot/vbnv_flash.c
new file mode 100644
index 0000000000..8b60be2b72
--- /dev/null
+++ b/src/vboot/vbnv_flash.c
@@ -0,0 +1,228 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/early_variables.h>
+#include <assert.h>
+#include <commonlib/region.h>
+#include <console/console.h>
+#include <spi_flash.h>
+#include <string.h>
+#include <vb2_api.h>
+#include <vboot_nvstorage.h>
+#include <vboot/vboot_common.h>
+#include <vboot/vbnv.h>
+#include <vboot/vbnv_layout.h>
+
+#define BLOB_SIZE VB2_NVDATA_SIZE
+
+struct vbnv_flash_ctx {
+	/* VBNV flash is initialized */
+	int initialized;
+
+	/* Offset of the current nvdata in SPI flash */
+	int blob_offset;
+
+	/* Offset of the topmost nvdata blob in SPI flash */
+	int top_offset;
+
+	/* SPI flash handler used when saving data */
+	struct spi_flash *flash;
+
+	/* FMAP descriptor of the NVRAM area */
+	struct region_device region;
+
+	/* Cache of the current nvdata */
+	uint8_t cache[BLOB_SIZE];
+};
+static struct vbnv_flash_ctx vbnv_flash CAR_GLOBAL;
+
+/*
+ * This code assumes that flash is erased to 1-bits, and write operations can
+ * only change 1-bits to 0-bits. So if the new contents only change 1-bits to
+ * 0-bits, we can reuse the current blob.
+ */
+static inline uint8_t erase_value(void)
+{
+	return 0xff;
+}
+
+static inline int can_overwrite(uint8_t current, uint8_t new)
+{
+	return (current & new) == new;
+}
+
+static int init_vbnv(void)
+{
+	struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash);
+	uint8_t buf[BLOB_SIZE];
+	uint8_t empty_blob[BLOB_SIZE];
+	int offset;
+	int i;
+
+	if (vboot_named_region_device("RW_NVRAM", &ctx->region) ||
+	    region_device_sz(&ctx->region) < BLOB_SIZE) {
+		printk(BIOS_ERR, "%s: failed to locate NVRAM\n", __func__);
+		return 1;
+	}
+
+	/* Prepare an empty blob to compare against. */
+	for (i = 0; i < BLOB_SIZE; i++)
+		empty_blob[i] = erase_value();
+
+	offset = 0;
+	ctx->top_offset = region_device_sz(&ctx->region) - BLOB_SIZE;
+
+	/*
+	 * after the loop, offset is supposed to point the blob right before
+	 * the first empty blob, the last blob in the nvram if there is no
+	 * empty blob, or the base of the region if the nvram has never been
+	 * used.
+	 */
+	for (i = 0; i <= ctx->top_offset; i += BLOB_SIZE) {
+		if (rdev_readat(&ctx->region, buf, i, BLOB_SIZE) < 0) {
+			printk(BIOS_ERR, "failed to read nvdata\n");
+			return 1;
+		}
+		if (!memcmp(buf, empty_blob, BLOB_SIZE))
+			break;
+		offset = i;
+	}
+
+	/* reread the nvdata and write it to the cache */
+	if (rdev_readat(&ctx->region, ctx->cache, offset, BLOB_SIZE) < 0) {
+		printk(BIOS_ERR, "failed to read nvdata\n");
+		return 1;
+	}
+
+	ctx->blob_offset = offset;
+	ctx->initialized = 1;
+
+	return 0;
+}
+
+static void vbnv_is_erasable(void)
+{
+	/*
+	 * We check whether the region is aligned or not in advance to ensure
+	 * we can erase the region when it's all used up.
+	 *
+	 * The region offset & size are determined by fmap.dts yet the check can
+	 * be confidently done only by the spi flash driver. We use the same
+	 * check as the one used by spi_flash_cmd_erase, which happens to be
+	 * common to all the spi flash parts we support.
+	 *
+	 * TODO: Check by calling can_erase implemented by each spi flash driver
+	 */
+	struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash);
+
+	assert(!(region_device_offset(&ctx->region) % ctx->flash->sector_size));
+	assert(!(region_device_sz(&ctx->region) % ctx->flash->sector_size));
+}
+
+static int vbnv_flash_probe(void)
+{
+	struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash);
+
+	if (!ctx->flash) {
+		ctx->flash = spi_flash_probe(CONFIG_BOOT_MEDIA_SPI_BUS, 0);
+		if (!ctx->flash) {
+			printk(BIOS_ERR, "failed to probe spi flash\n");
+			return 1;
+		}
+		/*
+		 * Called here instead of init_vbnv to reduce impact on boot
+		 * speed.
+		 */
+		vbnv_is_erasable();
+	}
+
+	/*
+	 * Handle the case where spi_flash_probe returns a CAR_GLOBAL
+	 * in early execution on x86 but then later is moved to RAM.
+	 */
+	ctx->flash = car_get_var_ptr(ctx->flash);
+
+	return 0;
+}
+
+static int erase_nvram(void)
+{
+	struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash);
+
+	if (vbnv_flash_probe())
+		return 1;
+
+	if (ctx->flash->erase(ctx->flash, region_device_offset(&ctx->region),
+			      region_device_sz(&ctx->region))) {
+		printk(BIOS_ERR, "failed to erase nvram\n");
+		return 1;
+	}
+
+	printk(BIOS_INFO, "nvram is cleared\n");
+	return 0;
+}
+
+void read_vbnv_flash(uint8_t *vbnv_copy)
+{
+	struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash);
+
+	if (!ctx->initialized)
+		if (init_vbnv())
+			return;  /* error */
+
+	memcpy(vbnv_copy, ctx->cache, BLOB_SIZE);
+}
+
+void save_vbnv_flash(const uint8_t *vbnv_copy)
+{
+	struct vbnv_flash_ctx *ctx = car_get_var_ptr(&vbnv_flash);
+	int new_offset;
+	int i;
+
+	if (!ctx->initialized)
+		if (init_vbnv())
+			return;  /* error */
+
+	/* Bail out if there have been no changes. */
+	if (!memcmp(vbnv_copy, ctx->cache, BLOB_SIZE))
+		return;
+
+	new_offset = ctx->blob_offset;
+
+	/* See if we can overwrite the current blob with the new one */
+	for (i = 0; i < BLOB_SIZE; i++) {
+		if (!can_overwrite(ctx->cache[i], vbnv_copy[i])) {
+			/* unable to overwrite. need to use the next blob */
+			new_offset += BLOB_SIZE;
+			if (new_offset > ctx->top_offset) {
+				if (erase_nvram())
+					return;  /* error */
+				new_offset = 0;
+			}
+			break;
+		}
+	}
+
+	if (!vbnv_flash_probe() &&
+	    !ctx->flash->write(ctx->flash,
+			       region_device_offset(&ctx->region) + new_offset,
+			       BLOB_SIZE, vbnv_copy)) {
+		/* write was successful. safely move pointer forward */
+		ctx->blob_offset = new_offset;
+		memcpy(ctx->cache, vbnv_copy, BLOB_SIZE);
+	} else {
+		printk(BIOS_ERR, "failed to save nvdata\n");
+	}
+}
diff --git a/src/vboot/vbnv_layout.h b/src/vboot/vbnv_layout.h
new file mode 100644
index 0000000000..59acd0c354
--- /dev/null
+++ b/src/vboot/vbnv_layout.h
@@ -0,0 +1,47 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2015 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __VBOOT_VBNV_LAYOUT_H__
+#define __VBOOT_VBNV_LAYOUT_H__
+
+#define VBOOT_VBNV_BLOCK_SIZE 16	/* Size of NV storage block in bytes */
+
+/* Constants for NV storage.  We use this rather than structs and
+ * bitfields so the data format is consistent across platforms and
+ * compilers.
+ */
+#define HEADER_OFFSET                0
+#define HEADER_MASK                     0xC0
+#define HEADER_SIGNATURE                0x40
+#define HEADER_FIRMWARE_SETTINGS_RESET  0x20
+#define HEADER_KERNEL_SETTINGS_RESET    0x10
+
+#define BOOT_OFFSET                  1
+#define BOOT_DEBUG_RESET_MODE           0x80
+#define BOOT_DISABLE_DEV_REQUEST        0x40
+#define BOOT_OPROM_NEEDED               0x20
+#define BOOT_TRY_B_COUNT_MASK           0x0F
+
+#define RECOVERY_OFFSET              2
+#define LOCALIZATION_OFFSET          3
+
+#define DEV_FLAGS_OFFSET             4
+#define DEV_BOOT_USB_MASK               0x01
+#define DEV_BOOT_SIGNED_ONLY_MASK       0x02
+
+#define KERNEL_FIELD_OFFSET         11
+#define CRC_OFFSET                  15
+
+#endif /* __VBOOT_VBNV_LAYOUT_H__ */
diff --git a/src/vboot/vboot_common.c b/src/vboot/vboot_common.c
new file mode 100644
index 0000000000..319e0dedfc
--- /dev/null
+++ b/src/vboot/vboot_common.c
@@ -0,0 +1,110 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <boot/coreboot_tables.h>
+#include <boot_device.h>
+#include <cbmem.h>
+#include <console/cbmem_console.h>
+#include <console/console.h>
+#include <fmap.h>
+#include <reset.h>
+#include <rules.h>
+#include <stddef.h>
+#include <string.h>
+#include <vboot/vboot_common.h>
+
+int vboot_named_region_device(const char *name, struct region_device *rdev)
+{
+	return fmap_locate_area_as_rdev(name, rdev);
+}
+
+/* ========================== VBOOT HANDOFF APIs =========================== */
+int vboot_get_handoff_info(void **addr, uint32_t *size)
+{
+	/*
+	 * vboot_handoff is present only after cbmem comes online. If we are in
+	 * pre-ram stage, then bail out early.
+	 */
+	if (ENV_BOOTBLOCK ||
+	    (ENV_VERSTAGE && IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK)))
+		return -1;
+
+	struct vboot_handoff *vboot_handoff;
+	vboot_handoff = cbmem_find(CBMEM_ID_VBOOT_HANDOFF);
+
+	if (vboot_handoff == NULL)
+		return -1;
+
+	*addr = vboot_handoff;
+
+	if (size)
+		*size = sizeof(*vboot_handoff);
+	return 0;
+}
+
+static int vboot_get_handoff_flag(uint32_t flag)
+{
+	struct vboot_handoff *vbho;
+
+	/*
+	 * If vboot_handoff cannot be found, return default value of flag as 0.
+	 */
+	if (vboot_get_handoff_info((void **)&vbho, NULL))
+		return 0;
+
+	return !!(vbho->init_params.out_flags & flag);
+}
+
+int vboot_handoff_skip_display_init(void)
+{
+	return !vboot_get_handoff_flag(VB_INIT_OUT_ENABLE_DISPLAY);
+}
+
+int vboot_handoff_check_developer_flag(void)
+{
+	return vboot_get_handoff_flag(VB_INIT_OUT_ENABLE_DEVELOPER);
+}
+
+int vboot_handoff_check_recovery_flag(void)
+{
+	return vboot_get_handoff_flag(VB_INIT_OUT_ENABLE_RECOVERY);
+}
+
+int vboot_handoff_get_recovery_reason(void)
+{
+	struct vboot_handoff *vbho;
+	VbSharedDataHeader *sd;
+
+	if (vboot_get_handoff_info((void **)&vbho, NULL))
+		return 0;
+
+	sd = (VbSharedDataHeader *)vbho->shared_data;
+
+	return sd->recovery_reason;
+}
+
+/* ============================ VBOOT REBOOT ============================== */
+void __attribute__((weak)) vboot_platform_prepare_reboot(void)
+{
+}
+
+void vboot_reboot(void)
+{
+	if (IS_ENABLED(CONFIG_CONSOLE_CBMEM_DUMP_TO_UART))
+		cbmem_dump_console();
+	vboot_platform_prepare_reboot();
+	hard_reset();
+	die("failed to reboot");
+}
diff --git a/src/vboot/vboot_common.h b/src/vboot/vboot_common.h
new file mode 100644
index 0000000000..684a66b2e2
--- /dev/null
+++ b/src/vboot/vboot_common.h
@@ -0,0 +1,104 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __VBOOT_VBOOT_COMMON_H__
+#define __VBOOT_VBOOT_COMMON_H__
+
+#include <commonlib/region.h>
+#include <stdint.h>
+#include <vboot_api.h>
+#include <vboot_struct.h>
+
+/* Locate vboot area by name. Returns 0 on success and -1 on error. */
+int vboot_named_region_device(const char *name, struct region_device *rdev);
+
+/*
+ * Function to check if there is a request to enter recovery mode. Returns
+ * reason code if request to enter recovery mode is present, otherwise 0.
+ */
+int vboot_check_recovery_request(void);
+
+/* ========================== VBOOT HANDOFF APIs =========================== */
+/*
+ * The vboot_handoff structure contains the data to be consumed by downstream
+ * firmware after firmware selection has been completed. Namely it provides
+ * vboot shared data as well as the flags from VbInit.
+ */
+struct vboot_handoff {
+	VbInitParams init_params;
+	uint32_t selected_firmware;
+	char shared_data[VB_SHARED_DATA_MIN_SIZE];
+} __attribute__((packed));
+
+/*
+ * vboot_get_handoff_info returns pointer to the vboot_handoff structure if
+ * available. vboot_handoff is available only after CBMEM comes online. If size
+ * is not NULL, size of the vboot_handoff structure is returned in it.
+ * Returns 0 on success and -1 on error.
+ */
+int vboot_get_handoff_info(void **addr, uint32_t *size);
+
+/*
+ * The following functions read vboot_handoff structure to obtain requested
+ * information. If vboot handoff is not available, 0 is returned by default.
+ * If vboot handoff is available:
+ * Returns 1 for flag if true
+ * Returns 0 for flag if false
+ * Returns value read for other fields
+ */
+int vboot_handoff_skip_display_init(void);
+int vboot_handoff_check_recovery_flag(void);
+int vboot_handoff_check_developer_flag(void);
+int vboot_handoff_get_recovery_reason(void);
+
+/* ============================ VBOOT REBOOT ============================== */
+/*
+ * vboot_reboot handles the reboot requests made by vboot_reference library. It
+ * allows the platform to run any preparation steps before the reboot and then
+ * does a hard reset.
+ */
+void vboot_reboot(void);
+
+/* Allow the platform to do any clean up work when vboot requests a reboot. */
+void vboot_platform_prepare_reboot(void);
+
+/* ============================ VBOOT RESUME ============================== */
+/*
+ * Save the provided hash digest to a secure location to check against in
+ * the resume path. Returns 0 on success, < 0 on error.
+ */
+int vboot_save_hash(void *digest, size_t digest_size);
+
+/*
+ * Retrieve the previously saved hash digest.  Returns 0 on success,
+ * < 0 on error.
+ */
+int vboot_retrieve_hash(void *digest, size_t digest_size);
+
+/*
+ * Determine if the platform is resuming from suspend. Returns 0 when
+ * not resuming, > 0 if resuming, and < 0 on error.
+ */
+int vboot_platform_is_resuming(void);
+
+/* ============================= VERSTAGE ================================== */
+/*
+ * Main logic for verified boot. verstage() is the stage entry point
+ * while the verstage_main() is just the core logic.
+ */
+void verstage_main(void);
+void verstage(void);
+void verstage_mainboard_init(void);
+
+#endif /* __VBOOT_VBOOT_COMMON_H__ */
diff --git a/src/vboot/vboot_handoff.c b/src/vboot/vboot_handoff.c
new file mode 100644
index 0000000000..b0bd04ca16
--- /dev/null
+++ b/src/vboot/vboot_handoff.c
@@ -0,0 +1,180 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/stages.h>
+#include <assert.h>
+#include <bootmode.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include <cbfs.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <console/vtxprintf.h>
+#include <fmap.h>
+#include <stdlib.h>
+#include <timestamp.h>
+#define NEED_VB20_INTERNALS  /* TODO: remove me! */
+#include <vb2_api.h>
+#include <vboot_struct.h>
+#include <vboot/vbnv.h>
+#include <vboot/misc.h>
+
+/**
+ * Sets vboot_handoff based on the information in vb2_shared_data
+ */
+static void fill_vboot_handoff(struct vboot_handoff *vboot_handoff,
+			       struct vb2_shared_data *vb2_sd)
+{
+	VbSharedDataHeader *vb_sd =
+		(VbSharedDataHeader *)vboot_handoff->shared_data;
+	uint32_t *oflags = &vboot_handoff->init_params.out_flags;
+
+	vb_sd->flags |= VBSD_BOOT_FIRMWARE_VBOOT2;
+
+	vboot_handoff->selected_firmware = vb2_sd->fw_slot;
+
+	vb_sd->firmware_index = vb2_sd->fw_slot;
+
+	vb_sd->magic = VB_SHARED_DATA_MAGIC;
+	vb_sd->struct_version = VB_SHARED_DATA_VERSION;
+	vb_sd->struct_size = sizeof(VbSharedDataHeader);
+	vb_sd->data_size = VB_SHARED_DATA_MIN_SIZE;
+	vb_sd->data_used = sizeof(VbSharedDataHeader);
+	vb_sd->fw_version_tpm = vb2_sd->fw_version_secdata;
+
+	if (get_write_protect_state())
+		vb_sd->flags |= VBSD_BOOT_FIRMWARE_WP_ENABLED;
+	if (get_sw_write_protect_state())
+		vb_sd->flags |= VBSD_BOOT_FIRMWARE_SW_WP_ENABLED;
+
+	if (vb2_sd->recovery_reason) {
+		vb_sd->firmware_index = 0xFF;
+		if (vb2_sd->flags & VB2_SD_FLAG_MANUAL_RECOVERY)
+			vb_sd->flags |= VBSD_BOOT_REC_SWITCH_ON;
+		*oflags |= VB_INIT_OUT_ENABLE_RECOVERY;
+		*oflags |= VB_INIT_OUT_CLEAR_RAM;
+		*oflags |= VB_INIT_OUT_ENABLE_DISPLAY;
+		*oflags |= VB_INIT_OUT_ENABLE_USB_STORAGE;
+	}
+	if (vb2_sd->flags & VB2_SD_DEV_MODE_ENABLED) {
+		*oflags |= VB_INIT_OUT_ENABLE_DEVELOPER;
+		*oflags |= VB_INIT_OUT_CLEAR_RAM;
+		*oflags |= VB_INIT_OUT_ENABLE_DISPLAY;
+		*oflags |= VB_INIT_OUT_ENABLE_USB_STORAGE;
+		vb_sd->flags |= VBSD_BOOT_DEV_SWITCH_ON;
+		vb_sd->flags |= VBSD_LF_DEV_SWITCH_ON;
+	}
+	/* TODO: Set these in depthcharge */
+	if (IS_ENABLED(CONFIG_VIRTUAL_DEV_SWITCH))
+		vb_sd->flags |= VBSD_HONOR_VIRT_DEV_SWITCH;
+	if (IS_ENABLED(CONFIG_EC_SOFTWARE_SYNC))
+		vb_sd->flags |= VBSD_EC_SOFTWARE_SYNC;
+	if (!IS_ENABLED(CONFIG_PHYSICAL_REC_SWITCH))
+		vb_sd->flags |= VBSD_BOOT_REC_SWITCH_VIRTUAL;
+	if (IS_ENABLED(CONFIG_VBOOT_EC_SLOW_UPDATE))
+		vb_sd->flags |= VBSD_EC_SLOW_UPDATE;
+	if (IS_ENABLED(CONFIG_VBOOT_OPROM_MATTERS)) {
+		vb_sd->flags |= VBSD_OPROM_MATTERS;
+		/*
+		 * Inform vboot if the display was enabled by dev/rec
+		 * mode or was requested by vboot kernel phase.
+		 */
+		if ((*oflags & VB_INIT_OUT_ENABLE_DISPLAY) ||
+		    vboot_wants_oprom()) {
+			vb_sd->flags |= VBSD_OPROM_LOADED;
+			*oflags |= VB_INIT_OUT_ENABLE_DISPLAY;
+		}
+	}
+
+	/* In vboot1, VBSD_FWB_TRIED is
+	 * set only if B is booted as explicitly requested. Therefore, if B is
+	 * booted because A was found bad, the flag should not be set. It's
+	 * better not to touch it if we can only ambiguously control it. */
+	/* if (vb2_sd->fw_slot)
+		vb_sd->flags |= VBSD_FWB_TRIED; */
+
+	/* copy kernel subkey if it's found */
+	if (vb2_sd->workbuf_preamble_size) {
+		struct vb2_fw_preamble *fp;
+		uintptr_t dst, src;
+		printk(BIOS_INFO, "Copying FW preamble\n");
+		fp = (struct vb2_fw_preamble *)((uintptr_t)vb2_sd +
+				vb2_sd->workbuf_preamble_offset);
+		src = (uintptr_t)&fp->kernel_subkey +
+				fp->kernel_subkey.key_offset;
+		dst = (uintptr_t)vb_sd + sizeof(VbSharedDataHeader);
+		assert(dst + fp->kernel_subkey.key_size <=
+		       (uintptr_t)vboot_handoff + sizeof(*vboot_handoff));
+		memcpy((void *)dst, (void *)src,
+		       fp->kernel_subkey.key_size);
+		vb_sd->data_used += fp->kernel_subkey.key_size;
+		vb_sd->kernel_subkey.key_offset =
+				dst - (uintptr_t)&vb_sd->kernel_subkey;
+		vb_sd->kernel_subkey.key_size = fp->kernel_subkey.key_size;
+		vb_sd->kernel_subkey.algorithm = fp->kernel_subkey.algorithm;
+		vb_sd->kernel_subkey.key_version =
+				fp->kernel_subkey.key_version;
+	}
+
+	vb_sd->recovery_reason = vb2_sd->recovery_reason;
+}
+
+void vboot_fill_handoff(void)
+{
+	struct vboot_handoff *vh;
+	struct vb2_shared_data *sd;
+
+	sd = vb2_get_shared_data();
+	sd->workbuf_hash_offset = 0;
+	sd->workbuf_hash_size = 0;
+
+	printk(BIOS_INFO, "creating vboot_handoff structure\n");
+	vh = cbmem_add(CBMEM_ID_VBOOT_HANDOFF, sizeof(*vh));
+	if (vh == NULL)
+		/* we don't need to failover gracefully here because this
+		 * shouldn't happen with the image that has passed QA. */
+		die("failed to allocate vboot_handoff structure\n");
+
+	memset(vh, 0, sizeof(*vh));
+
+	/* needed until we finish transtion to vboot2 for kernel verification */
+	fill_vboot_handoff(vh, sd);
+
+	/*
+	 * The recovery mode switch is cleared (typically backed by EC) here
+	 * to allow multiple queries to get_recovery_mode_switch() and have
+	 * them return consistent results during the verified boot path as well
+	 * as dram initialization. x86 systems ignore the saved dram settings
+	 * in the recovery path in order to start from a clean slate. Therefore
+	 * clear the state here since this function is called when memory
+	 * is known to be up.
+	 */
+	clear_recovery_mode_switch();
+}
+
+/*
+ * For platforms that employ VBOOT_DYNAMIC_WORK_BUFFER, the vboot
+ * verification doesn't happen until after cbmem is brought online.
+ * Therefore, the vboot results would not be initialized so don't
+ * automatically add results when cbmem comes online.
+ */
+#if !IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER)
+static void vb2_fill_handoff_cbmem(int unused)
+{
+	vboot_fill_handoff();
+}
+ROMSTAGE_CBMEM_INIT_HOOK(vb2_fill_handoff_cbmem)
+#endif
diff --git a/src/vboot/vboot_loader.c b/src/vboot/vboot_loader.c
new file mode 100644
index 0000000000..7395fd7d92
--- /dev/null
+++ b/src/vboot/vboot_loader.c
@@ -0,0 +1,159 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/early_variables.h>
+#include <cbfs.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <rmodule.h>
+#include <rules.h>
+#include <string.h>
+#include <vboot/misc.h>
+#include <vboot/symbols.h>
+#include <vboot/vboot_common.h>
+
+/* The stage loading code is compiled and entered from multiple stages. The
+ * helper functions below attempt to provide more clarity on when certain
+ * code should be called. */
+
+static int verification_should_run(void)
+{
+	if (ENV_VERSTAGE && IS_ENABLED(CONFIG_SEPARATE_VERSTAGE))
+		return 1;
+
+	if (!IS_ENABLED(CONFIG_SEPARATE_VERSTAGE)) {
+		if (ENV_ROMSTAGE &&
+		    IS_ENABLED(CONFIG_VBOOT_STARTS_IN_ROMSTAGE))
+			return 1;
+		if (ENV_BOOTBLOCK &&
+		    IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK))
+			return 1;
+	}
+
+	return 0;
+}
+
+static int verstage_should_load(void)
+{
+	if (!IS_ENABLED(CONFIG_SEPARATE_VERSTAGE))
+		return 0;
+
+	if (ENV_ROMSTAGE && IS_ENABLED(CONFIG_VBOOT_STARTS_IN_ROMSTAGE))
+		return 1;
+
+	if (ENV_BOOTBLOCK && IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK))
+		return 1;
+
+	return 0;
+}
+
+static int vboot_executed CAR_GLOBAL;
+
+int vb2_logic_executed(void)
+{
+	/* If this stage is supposed to run the vboot logic ensure it has been
+	 * executed. */
+	if (verification_should_run() && car_get_var(vboot_executed))
+		return 1;
+
+	/* If this stage is supposed to load verstage and verstage is returning
+	 * back to the calling stage check that it has been executed. */
+	if (verstage_should_load() && IS_ENABLED(CONFIG_RETURN_FROM_VERSTAGE))
+		if (car_get_var(vboot_executed))
+			return 1;
+
+	/* Handle all other stages post vboot execution. */
+	if (!ENV_BOOTBLOCK) {
+		if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK))
+			return 1;
+		if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_ROMSTAGE) &&
+				!ENV_ROMSTAGE)
+			return 1;
+	}
+
+	return 0;
+}
+
+static void vboot_prepare(void)
+{
+	if (verification_should_run()) {
+		verstage_main();
+		car_set_var(vboot_executed, 1);
+		vb2_save_recovery_reason_vbnv();
+	} else if (verstage_should_load()) {
+		struct cbfsf file;
+		struct prog verstage =
+			PROG_INIT(PROG_VERSTAGE,
+				CONFIG_CBFS_PREFIX "/verstage");
+
+		printk(BIOS_DEBUG, "VBOOT: Loading verstage.\n");
+
+		/* load verstage from RO */
+		if (cbfs_boot_locate(&file, prog_name(&verstage), NULL))
+			die("failed to load verstage");
+
+		cbfs_file_data(prog_rdev(&verstage), &file);
+
+		if (cbfs_prog_stage_load(&verstage))
+			die("failed to load verstage");
+
+		/* verify and select a slot */
+		prog_run(&verstage);
+
+		/* This is not actually possible to hit this condition at
+		 * runtime, but this provides a hint to the compiler for dead
+		 * code elimination below. */
+		if (!IS_ENABLED(CONFIG_RETURN_FROM_VERSTAGE))
+			return;
+
+		car_set_var(vboot_executed, 1);
+	}
+
+	/*
+	 * Fill in vboot cbmem objects before moving to ramstage so all
+	 * downstream users have access to vboot results. This path only
+	 * applies to platforms employing VBOOT_DYNAMIC_WORK_BUFFER because
+	 * cbmem comes online prior to vboot verification taking place. For
+	 * other platforms the vboot cbmem objects are initialized when
+	 * cbmem comes online.
+	 */
+	if (ENV_ROMSTAGE && IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER)) {
+		vb2_store_selected_region();
+		vboot_fill_handoff();
+	}
+}
+
+static int vboot_locate(struct cbfs_props *props)
+{
+	struct region selected_region;
+
+	/* Don't honor vboot results until the vboot logic has run. */
+	if (!vb2_logic_executed())
+		return -1;
+
+	if (vb2_get_selected_region(&selected_region))
+		return -1;
+
+	props->offset = region_offset(&selected_region);
+	props->size = region_sz(&selected_region);
+
+	return 0;
+}
+
+const struct cbfs_locator vboot_locator = {
+	.name = "VBOOT",
+	.prepare = vboot_prepare,
+	.locate = vboot_locate,
+};
diff --git a/src/vboot/vboot_logic.c b/src/vboot/vboot_logic.c
new file mode 100644
index 0000000000..bc6ab48191
--- /dev/null
+++ b/src/vboot/vboot_logic.c
@@ -0,0 +1,415 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <antirollback.h>
+#include <arch/exception.h>
+#include <assert.h>
+#include <bootmode.h>
+#include <console/console.h>
+#include <console/vtxprintf.h>
+#include <delay.h>
+#include <string.h>
+#include <timestamp.h>
+#include <vb2_api.h>
+#include <vboot/misc.h>
+#include <vboot/vbnv.h>
+
+/* The max hash size to expect is for SHA512. */
+#define VBOOT_MAX_HASH_SIZE VB2_SHA512_DIGEST_SIZE
+
+#define TODO_BLOCK_SIZE 1024
+
+static int is_slot_a(struct vb2_context *ctx)
+{
+	return !(ctx->flags & VB2_CONTEXT_FW_SLOT_B);
+}
+
+/* exports */
+
+void vb2ex_printf(const char *func, const char *fmt, ...)
+{
+	va_list args;
+
+	printk(BIOS_INFO, "VB2:%s() ", func);
+	va_start(args, fmt);
+	do_printk_va_list(BIOS_INFO, fmt, args);
+	va_end(args);
+
+	return;
+}
+
+int vb2ex_tpm_clear_owner(struct vb2_context *ctx)
+{
+	uint32_t rv;
+	printk(BIOS_INFO, "Clearing TPM owner\n");
+	rv = tpm_clear_and_reenable();
+	if (rv)
+		return VB2_ERROR_EX_TPM_CLEAR_OWNER;
+	return VB2_SUCCESS;
+}
+
+int vb2ex_read_resource(struct vb2_context *ctx,
+			enum vb2_resource_index index,
+			uint32_t offset,
+			void *buf,
+			uint32_t size)
+{
+	struct region_device rdev;
+	const char *name;
+
+	switch (index) {
+	case VB2_RES_GBB:
+		name = "GBB";
+		break;
+	case VB2_RES_FW_VBLOCK:
+		if (is_slot_a(ctx))
+			name = "VBLOCK_A";
+		else
+			name = "VBLOCK_B";
+		break;
+	default:
+		return VB2_ERROR_EX_READ_RESOURCE_INDEX;
+	}
+
+	if (vboot_named_region_device(name, &rdev))
+		return VB2_ERROR_EX_READ_RESOURCE_SIZE;
+
+	if (rdev_readat(&rdev, buf, offset, size) != size)
+		return VB2_ERROR_EX_READ_RESOURCE_SIZE;
+
+	return VB2_SUCCESS;
+}
+
+/* No-op stubs that can be overridden by SoCs with hardware crypto support. */
+__attribute__((weak))
+int vb2ex_hwcrypto_digest_init(enum vb2_hash_algorithm hash_alg,
+			       uint32_t data_size)
+{
+	return VB2_ERROR_EX_HWCRYPTO_UNSUPPORTED;
+}
+
+__attribute__((weak))
+int vb2ex_hwcrypto_digest_extend(const uint8_t *buf, uint32_t size)
+{
+	BUG();	/* Should never get called if init() returned an error. */
+	return VB2_ERROR_UNKNOWN;
+}
+
+__attribute__((weak))
+int vb2ex_hwcrypto_digest_finalize(uint8_t *digest, uint32_t digest_size)
+{
+	BUG();	/* Should never get called if init() returned an error. */
+	return VB2_ERROR_UNKNOWN;
+}
+
+static int handle_digest_result(void *slot_hash, size_t slot_hash_sz)
+{
+	int is_resume;
+
+	/*
+	 * Nothing to do since resuming on the platform doesn't require
+	 * vboot verification again.
+	 */
+	if (!IS_ENABLED(CONFIG_RESUME_PATH_SAME_AS_BOOT))
+		return 0;
+
+	/*
+	 * Assume that if vboot doesn't start in bootblock verified
+	 * RW memory init code is not employed. i.e. memory init code
+	 * lives in RO CBFS.
+	 */
+	if (!IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK))
+		return 0;
+
+	is_resume = vboot_platform_is_resuming();
+
+	if (is_resume > 0) {
+		uint8_t saved_hash[VBOOT_MAX_HASH_SIZE];
+		const size_t saved_hash_sz = sizeof(saved_hash);
+
+		assert(slot_hash_sz == saved_hash_sz);
+
+		printk(BIOS_DEBUG, "Platform is resuming.\n");
+
+		if (vboot_retrieve_hash(saved_hash, saved_hash_sz)) {
+			printk(BIOS_ERR, "Couldn't retrieve saved hash.\n");
+			return -1;
+		}
+
+		if (memcmp(saved_hash, slot_hash, slot_hash_sz)) {
+			printk(BIOS_ERR, "Hash mismatch on resume.\n");
+			return -1;
+		}
+	} else if (is_resume < 0)
+		printk(BIOS_ERR, "Unable to determine if platform resuming.\n");
+
+	printk(BIOS_DEBUG, "Saving vboot hash.\n");
+
+	/* Always save the hash for the current boot. */
+	if (vboot_save_hash(slot_hash, slot_hash_sz)) {
+		printk(BIOS_ERR, "Error saving vboot hash.\n");
+		/* Though this is an error don't report it up since it could
+		 * lead to a reboot loop. The consequence of this is that
+		 * we will most likely fail resuming because of EC issues or
+		 * the hash digest not matching. */
+		return 0;
+	}
+
+	return 0;
+}
+
+static int hash_body(struct vb2_context *ctx, struct region_device *fw_main)
+{
+	uint64_t load_ts;
+	uint32_t expected_size;
+	uint8_t block[TODO_BLOCK_SIZE];
+	uint8_t hash_digest[VBOOT_MAX_HASH_SIZE];
+	const size_t hash_digest_sz = sizeof(hash_digest);
+	size_t block_size = sizeof(block);
+	size_t offset;
+	int rv;
+
+	/* Clear the full digest so that any hash digests less than the
+	 * max have trailing zeros. */
+	memset(hash_digest, 0, hash_digest_sz);
+
+	/*
+	 * Since loading the firmware and calculating its hash is intertwined,
+	 * we use this little trick to measure them separately and pretend it
+	 * was first loaded and then hashed in one piece with the timestamps.
+	 * (This split won't make sense with memory-mapped media like on x86.)
+	 */
+	load_ts = timestamp_get();
+	timestamp_add(TS_START_HASH_BODY, load_ts);
+
+	expected_size = region_device_sz(fw_main);
+	offset = 0;
+
+	/* Start the body hash */
+	rv = vb2api_init_hash(ctx, VB2_HASH_TAG_FW_BODY, &expected_size);
+	if (rv)
+		return rv;
+
+	/*
+	 * Honor vboot's RW slot size. The expected size is pulled out of
+	 * the preamble and obtained through vb2api_init_hash() above. By
+	 * creating sub region the RW slot portion of the boot media is
+	 * limited.
+	 */
+	if (rdev_chain(fw_main, fw_main, 0, expected_size)) {
+		printk(BIOS_ERR, "Unable to restrict CBFS size.\n");
+		return VB2_ERROR_UNKNOWN;
+	}
+
+	/* Extend over the body */
+	while (expected_size) {
+		uint64_t temp_ts;
+		if (block_size > expected_size)
+			block_size = expected_size;
+
+		temp_ts = timestamp_get();
+		if (rdev_readat(fw_main, block, offset, block_size) < 0)
+			return VB2_ERROR_UNKNOWN;
+		load_ts += timestamp_get() - temp_ts;
+
+		rv = vb2api_extend_hash(ctx, block, block_size);
+		if (rv)
+			return rv;
+
+		expected_size -= block_size;
+		offset += block_size;
+	}
+
+	timestamp_add(TS_DONE_LOADING, load_ts);
+	timestamp_add_now(TS_DONE_HASHING);
+
+	/* Check the result (with RSA signature verification) */
+	rv = vb2api_check_hash_get_digest(ctx, hash_digest, hash_digest_sz);
+	if (rv)
+		return rv;
+
+	timestamp_add_now(TS_END_HASH_BODY);
+
+	if (handle_digest_result(hash_digest, hash_digest_sz))
+		return VB2_ERROR_UNKNOWN;
+
+	return VB2_SUCCESS;
+}
+
+static int locate_firmware(struct vb2_context *ctx,
+				struct region_device *fw_main)
+{
+	const char *name;
+
+	if (is_slot_a(ctx))
+		name = "FW_MAIN_A";
+	else
+		name = "FW_MAIN_B";
+
+	return vboot_named_region_device(name, fw_main);
+}
+
+/**
+ * Save non-volatile and/or secure data if needed.
+ */
+static void save_if_needed(struct vb2_context *ctx)
+{
+	if (ctx->flags & VB2_CONTEXT_NVDATA_CHANGED) {
+		printk(BIOS_INFO, "Saving nvdata\n");
+		save_vbnv(ctx->nvdata);
+		ctx->flags &= ~VB2_CONTEXT_NVDATA_CHANGED;
+	}
+	if (ctx->flags & VB2_CONTEXT_SECDATA_CHANGED) {
+		printk(BIOS_INFO, "Saving secdata\n");
+		antirollback_write_space_firmware(ctx);
+		ctx->flags &= ~VB2_CONTEXT_SECDATA_CHANGED;
+	}
+}
+
+static uint32_t extend_pcrs(struct vb2_context *ctx)
+{
+	return tpm_extend_pcr(ctx, 0, BOOT_MODE_PCR) ||
+	       tpm_extend_pcr(ctx, 1, HWID_DIGEST_PCR);
+}
+
+/**
+ * Verify and select the firmware in the RW image
+ *
+ * TODO: Avoid loading a stage twice (once in hash_body & again in load_stage).
+ * when per-stage verification is ready.
+ */
+void verstage_main(void)
+{
+	struct vb2_context ctx;
+	struct region_device fw_main;
+	int rv;
+
+	timestamp_add_now(TS_START_VBOOT);
+
+	/* Set up context and work buffer */
+	vb2_init_work_context(&ctx);
+
+	/* Read nvdata from a non-volatile storage. */
+	read_vbnv(ctx.nvdata);
+
+	/* Set S3 resume flag if vboot should behave differently when selecting
+	 * which slot to boot.  This is only relevant to vboot if the platform
+	 * does verification of memory init and thus must ensure it resumes with
+	 * the same slot that it booted from. */
+	if (IS_ENABLED(CONFIG_RESUME_PATH_SAME_AS_BOOT) &&
+	    IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK) &&
+	    vboot_platform_is_resuming())
+		ctx.flags |= VB2_CONTEXT_S3_RESUME;
+
+	/* Read secdata from TPM. Initialize TPM if secdata not found. We don't
+	 * check the return value here because vb2api_fw_phase1 will catch
+	 * invalid secdata and tell us what to do (=reboot). */
+	timestamp_add_now(TS_START_TPMINIT);
+	antirollback_read_space_firmware(&ctx);
+	timestamp_add_now(TS_END_TPMINIT);
+
+	if (!IS_ENABLED(CONFIG_VIRTUAL_DEV_SWITCH) &&
+	    get_developer_mode_switch())
+		ctx.flags |= VB2_CONTEXT_FORCE_DEVELOPER_MODE;
+
+	if (get_recovery_mode_switch()) {
+		ctx.flags |= VB2_CONTEXT_FORCE_RECOVERY_MODE;
+		if (IS_ENABLED(CONFIG_VBOOT_DISABLE_DEV_ON_RECOVERY))
+			ctx.flags |= VB2_DISABLE_DEVELOPER_MODE;
+	}
+
+	if (IS_ENABLED(CONFIG_WIPEOUT_SUPPORTED) && get_wipeout_mode_switch())
+		ctx.flags |= VB2_CONTEXT_FORCE_WIPEOUT_MODE;
+
+	if (IS_ENABLED(CONFIG_LID_SWITCH) && !get_lid_switch())
+		ctx.flags |= VB2_CONTEXT_NOFAIL_BOOT;
+
+	/* Do early init (set up secdata and NVRAM, load GBB) */
+	printk(BIOS_INFO, "Phase 1\n");
+	rv = vb2api_fw_phase1(&ctx);
+
+	if (rv) {
+		/*
+		 * If vb2api_fw_phase1 fails, check for return value.
+		 * If it is set to VB2_ERROR_API_PHASE1_RECOVERY, then continue
+		 * into recovery mode.
+		 * For any other error code, save context if needed and reboot.
+		 */
+		if (rv == VB2_ERROR_API_PHASE1_RECOVERY) {
+			printk(BIOS_INFO, "Recovery requested (%x)\n", rv);
+			save_if_needed(&ctx);
+			extend_pcrs(&ctx);	/* ignore failures */
+			timestamp_add_now(TS_END_VBOOT);
+			return;
+		}
+
+		printk(BIOS_INFO, "Reboot reqested (%x)\n", rv);
+		save_if_needed(&ctx);
+		vboot_reboot();
+	}
+
+	/* Determine which firmware slot to boot (based on NVRAM) */
+	printk(BIOS_INFO, "Phase 2\n");
+	rv = vb2api_fw_phase2(&ctx);
+	if (rv) {
+		printk(BIOS_INFO, "Reboot requested (%x)\n", rv);
+		save_if_needed(&ctx);
+		vboot_reboot();
+	}
+
+	/* Try that slot (verify its keyblock and preamble) */
+	printk(BIOS_INFO, "Phase 3\n");
+	timestamp_add_now(TS_START_VERIFY_SLOT);
+	rv = vb2api_fw_phase3(&ctx);
+	timestamp_add_now(TS_END_VERIFY_SLOT);
+	if (rv) {
+		printk(BIOS_INFO, "Reboot requested (%x)\n", rv);
+		save_if_needed(&ctx);
+		vboot_reboot();
+	}
+
+	printk(BIOS_INFO, "Phase 4\n");
+	rv = locate_firmware(&ctx, &fw_main);
+	if (rv)
+		die("Failed to read FMAP to locate firmware");
+
+	rv = hash_body(&ctx, &fw_main);
+	save_if_needed(&ctx);
+	if (rv) {
+		printk(BIOS_INFO, "Reboot requested (%x)\n", rv);
+		vboot_reboot();
+	}
+
+	rv = extend_pcrs(&ctx);
+	if (rv) {
+		printk(BIOS_WARNING, "Failed to extend TPM PCRs (%#x)\n", rv);
+		vb2api_fail(&ctx, VB2_RECOVERY_RO_TPM_U_ERROR, rv);
+		save_if_needed(&ctx);
+		vboot_reboot();
+	}
+
+	/* Lock TPM */
+	rv = antirollback_lock_space_firmware();
+	if (rv) {
+		printk(BIOS_INFO, "Failed to lock TPM (%x)\n", rv);
+		vb2api_fail(&ctx, VB2_RECOVERY_RO_TPM_L_ERROR, 0);
+		save_if_needed(&ctx);
+		vboot_reboot();
+	}
+
+	printk(BIOS_INFO, "Slot %c is selected\n", is_slot_a(&ctx) ? 'A' : 'B');
+	vb2_set_selected_region(region_device_region(&fw_main));
+	timestamp_add_now(TS_END_VBOOT);
+}
diff --git a/src/vboot/verstage.c b/src/vboot/verstage.c
new file mode 100644
index 0000000000..0ec9ca6d27
--- /dev/null
+++ b/src/vboot/verstage.c
@@ -0,0 +1,44 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/exception.h>
+#include <arch/hlt.h>
+#include <console/console.h>
+#include <program_loading.h>
+#include <vboot/vboot_common.h>
+
+void __attribute__((weak)) verstage_mainboard_init(void)
+{
+	/* Default empty implementation. */
+}
+
+void verstage(void)
+{
+	console_init();
+	exception_init();
+	verstage_mainboard_init();
+
+	if (IS_ENABLED(CONFIG_RETURN_FROM_VERSTAGE)) {
+		verstage_main();
+	} else {
+		run_romstage();
+		hlt();
+	}
+}
+
+#if !IS_ENABLED(CONFIG_CHIPSET_PROVIDES_VERSTAGE_MAIN_SYMBOL)
+/* This is for boards that rely on main() for an entry point of a stage. */
+void main(void) __attribute__((alias ("verstage")));
+#endif