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

 /* Copyright 2020 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.
  *
  * User interfaces for developer and recovery mode menus.
  */

 #include "2api.h"
 #include "2common.h"
 #include "2misc.h"
 #include "2nvstorage.h"
 #include "2return_codes.h"
 #include "2secdata.h"
 #include "2ui.h"
 #include "2ui_private.h"
 #include "vboot_api.h"  /* For VB_SHUTDOWN_REQUEST_POWER_BUTTON */
 #include "vboot_kernel.h"

 #define KEY_DELAY_MS 20  /* Delay between key scans in UI loops */

 /*****************************************************************************/
 /* Global variables */

 enum power_button_state power_button;
 int invalid_disk_last = -1;

 /*****************************************************************************/
 /* Utility functions */

 /**
  * Checks GBB flags against VbExIsShutdownRequested() shutdown request to
  * determine if a shutdown is required.
  *
  * @param ctx		Context pointer
  * @param key		Pressed key (VB_BUTTON_POWER_SHORT_PRESS)
  * @return true if a shutdown is required, or false otherwise.
  */
 int shutdown_required(struct vb2_context *ctx, uint32_t key)
 {
 	struct vb2_gbb_header *gbb = vb2_get_gbb(ctx);
 	uint32_t shutdown_request = VbExIsShutdownRequested();

 	/*
 	 * Ignore power button push until after we have seen it released.
 	 * This avoids shutting down immediately if the power button is still
 	 * being held on startup. After we've recognized a valid power button
 	 * push then don't report the event until after the button is released.
 	 */
 	if (shutdown_request & VB_SHUTDOWN_REQUEST_POWER_BUTTON) {
 		shutdown_request &= ~VB_SHUTDOWN_REQUEST_POWER_BUTTON;
 		if (power_button == POWER_BUTTON_RELEASED)
 			power_button = POWER_BUTTON_PRESSED;
 	} else {
 		if (power_button == POWER_BUTTON_PRESSED)
 			shutdown_request |= VB_SHUTDOWN_REQUEST_POWER_BUTTON;
 		power_button = POWER_BUTTON_RELEASED;
 	}

 	if (key == VB_BUTTON_POWER_SHORT_PRESS)
 		shutdown_request |= VB_SHUTDOWN_REQUEST_POWER_BUTTON;

 	/* If desired, ignore shutdown request due to lid closure. */
 	if (gbb->flags & VB2_GBB_FLAG_DISABLE_LID_SHUTDOWN)
 		shutdown_request &= ~VB_SHUTDOWN_REQUEST_LID_CLOSED;

 	/*
 	 * In detachables, disable shutdown due to power button.
 	 * It is used for menu selection instead.
 	 */
 	if (DETACHABLE)
 		shutdown_request &= ~VB_SHUTDOWN_REQUEST_POWER_BUTTON;

 	return !!shutdown_request;
 }

 /*****************************************************************************/
 /* Menu navigation actions */

 /**
  * Update selected_item, taking into account disabled indices (from
  * disabled_item_mask).  The selection does not wrap, meaning that we block
  * on the 0 or max index when we hit the top or bottom of the menu.
  */
 vb2_error_t menu_up_action(struct vb2_ui_context *ui)
 {
 	int item;

 	if (!DETACHABLE && ui->key == VB_BUTTON_VOL_UP_SHORT_PRESS)
 		return VB2_REQUEST_UI_CONTINUE;

 	item = ui->state.selected_item - 1;
 	while (item >= 0 &&
 	       ((1 << item) & ui->state.disabled_item_mask))
 		item--;
 	/* Only update if item is valid */
 	if (item >= 0)
 		ui->state.selected_item = item;

 	return VB2_REQUEST_UI_CONTINUE;
 }

 vb2_error_t menu_down_action(struct vb2_ui_context *ui)
 {
 	int item;

 	if (!DETACHABLE && ui->key == VB_BUTTON_VOL_DOWN_SHORT_PRESS)
 		return VB2_REQUEST_UI_CONTINUE;

 	item = ui->state.selected_item + 1;
 	while (item < ui->state.screen->num_items &&
 	       ((1 << item) & ui->state.disabled_item_mask))
 		item++;
 	/* Only update if item is valid */
 	if (item < ui->state.screen->num_items)
 		ui->state.selected_item = item;

 	return VB2_REQUEST_UI_CONTINUE;
 }

 /**
  * Navigate to the target screen of the current menu item selection.
  */
 vb2_error_t menu_select_action(struct vb2_ui_context *ui)
 {
 	const struct vb2_menu_item *menu_item;

 	if (!DETACHABLE && ui->key == VB_BUTTON_POWER_SHORT_PRESS)
 		return VB2_REQUEST_UI_CONTINUE;

 	if (ui->state.screen->num_items == 0)
 		return VB2_REQUEST_UI_CONTINUE;

 	menu_item = &ui->state.screen->items[ui->state.selected_item];

 	if (menu_item->action) {
 		VB2_DEBUG("Menu item <%s> run action\n", menu_item->text);
 		return menu_item->action(ui);
 	} else if (menu_item->target) {
 		VB2_DEBUG("Menu item <%s> to target screen %#x\n",
 			  menu_item->text, menu_item->target);
 		return change_screen(ui, menu_item->target);
 	}

 	VB2_DEBUG("Menu item <%s> no action or target screen\n",
 		  menu_item->text);
 	return VB2_REQUEST_UI_CONTINUE;
 }

 /**
  * Return back to the previous screen.
  */
 vb2_error_t vb2_ui_back_action(struct vb2_ui_context *ui)
 {
 	/* TODO(kitching): Return to previous screen instead of root screen. */
 	return change_screen(ui, ui->root_screen->id);
 }

 /**
  * Context-dependent keyboard shortcut Ctrl+D.
  *
  * - Manual recovery mode: Change to dev mode transition screen.
  * - Developer mode: Boot from internal disk (TODO).
  */
 vb2_error_t ctrl_d_action(struct vb2_ui_context *ui)
 {
 	if (vb2_allow_recovery(ui->ctx))
 		return change_screen(ui, VB2_SCREEN_RECOVERY_TO_DEV);
 	return VB2_REQUEST_UI_CONTINUE;
 }

 /*****************************************************************************/
 /* Action lookup tables */

 static struct input_action action_table[] = {
 	{ VB_KEY_UP,				menu_up_action },
 	{ VB_KEY_DOWN,				menu_down_action },
 	{ VB_KEY_ENTER,  			menu_select_action },
 	{ VB_BUTTON_VOL_UP_SHORT_PRESS, 	menu_up_action },
 	{ VB_BUTTON_VOL_DOWN_SHORT_PRESS, 	menu_down_action },
 	{ VB_BUTTON_POWER_SHORT_PRESS, 		menu_select_action },
 	{ VB_KEY_ESC, 			 	vb2_ui_back_action },
 	{ VB_KEY_CTRL('D'),		 	ctrl_d_action },
 	{ ' ',				 	vb2_ui_recovery_to_dev_action },
 };

 vb2_error_t (*input_action_lookup(int key))(struct vb2_ui_context *ui)
 {
 	int i;
 	for (i = 0; i < ARRAY_SIZE(action_table); i++)
 		if (action_table[i].key == key)
 			return action_table[i].action;
 	return NULL;
 }

 /*****************************************************************************/
 /* Core UI functions */

 vb2_error_t change_screen(struct vb2_ui_context *ui, enum vb2_screen id)
 {
 	const struct vb2_screen_info *new_screen_info = vb2_get_screen_info(id);

 	if (new_screen_info == NULL) {
 		VB2_DEBUG("ERROR: Screen entry %#x not found; ignoring\n", id);
 		return VB2_REQUEST_UI_CONTINUE;
 	}

 	memset(&ui->state, 0, sizeof(ui->state));
 	ui->state.screen = new_screen_info;

 	if (ui->state.screen->init)
 		return ui->state.screen->init(ui);

 	return VB2_REQUEST_UI_CONTINUE;
 }

 vb2_error_t ui_loop(struct vb2_context *ctx, enum vb2_screen root_screen_id,
 		    vb2_error_t (*global_action)(struct vb2_ui_context *ui))
 {
 	struct vb2_ui_context ui;
 	struct vb2_screen_state prev_state;
 	uint32_t key_flags;
 	vb2_error_t (*action)(struct vb2_ui_context *ui);
 	vb2_error_t rv;

 	memset(&ui, 0, sizeof(ui));
 	ui.ctx = ctx;
 	ui.root_screen = vb2_get_screen_info(root_screen_id);
 	if (ui.root_screen == NULL)
 		VB2_DIE("Root screen not found.\n");
 	rv = change_screen(&ui, ui.root_screen->id);
 	if (rv != VB2_REQUEST_UI_CONTINUE)
 		return rv;
 	memset(&prev_state, 0, sizeof(prev_state));

 	while (1) {
 		/* Draw if there are state changes. */
 		if (memcmp(&prev_state, &ui.state, sizeof(ui.state))) {
 			memcpy(&prev_state, &ui.state, sizeof(ui.state));

 			VB2_DEBUG("<%s> menu item <%s>\n",
 				  ui.state.screen->name,
 				  ui.state.screen->num_items ?
 				  ui.state.screen->items[
 				  ui.state.selected_item].text : "null");

 			vb2ex_display_ui(ui.state.screen->id, ui.locale_id,
 					 ui.state.selected_item,
 					 ui.state.disabled_item_mask);
 		}

 		/* Run screen action. */
 		if (ui.state.screen->action) {
 			rv = ui.state.screen->action(&ui);
 			if (rv != VB2_REQUEST_UI_CONTINUE)
 				return rv;
 		}

 		/* Grab new keyboard input. */
 		ui.key = VbExKeyboardReadWithFlags(&key_flags);
 		ui.key_trusted = !!(key_flags & VB_KEY_FLAG_TRUSTED_KEYBOARD);

 		/* Check for shutdown request. */
 		if (shutdown_required(ctx, ui.key)) {
 			VB2_DEBUG("Shutdown required!\n");
 			return VB2_REQUEST_SHUTDOWN;
 		}

 		/* Run input action function if found. */
 		action = input_action_lookup(ui.key);
 		if (action) {
 			rv = action(&ui);
 			if (rv != VB2_REQUEST_UI_CONTINUE)
 				return rv;
 		} else if (ui.key) {
 			VB2_DEBUG("Pressed key %#x, trusted? %d\n",
 				  ui.key, ui.key_trusted);
 		}

 		/* Reset keyboard input. */
 		ui.key = 0;
 		ui.key_trusted = 0;

 		/* Run global action function if available. */
 		if (global_action) {
 			rv = global_action(&ui);
 			if (rv != VB2_REQUEST_UI_CONTINUE)
 				return rv;
 		}

 		/* Delay. */
 		VbExSleepMs(KEY_DELAY_MS);
 	}

 	return VB2_SUCCESS;
 }

 /*****************************************************************************/
 /* Developer mode */

 vb2_error_t vb2_developer_menu(struct vb2_context *ctx)
 {
 	enum vb2_dev_default_boot default_boot;

 	/* If dev mode was disabled, loop forever. */
 	if (!vb2_dev_boot_allowed(ctx))
 		while (1);

 	/* Boot from the default option. */
 	default_boot = vb2_get_dev_boot_target(ctx);

 	/* Boot legacy does not return on success */
 	if (default_boot == VB2_DEV_DEFAULT_BOOT_LEGACY &&
 	    vb2_dev_boot_legacy_allowed(ctx) &&
 	    VbExLegacy(VB_ALTFW_DEFAULT) == VB2_SUCCESS)
 		return VB2_SUCCESS;

 	if (default_boot == VB2_DEV_DEFAULT_BOOT_USB &&
 	    vb2_dev_boot_usb_allowed(ctx) &&
 	    VbTryLoadKernel(ctx, VB_DISK_FLAG_REMOVABLE) == VB2_SUCCESS)
 		return VB2_SUCCESS;

 	return VbTryLoadKernel(ctx, VB_DISK_FLAG_FIXED);
 }

 /*****************************************************************************/
 /* Broken recovery */

 vb2_error_t vb2_broken_recovery_menu(struct vb2_context *ctx)
 {
 	return ui_loop(ctx, VB2_SCREEN_RECOVERY_BROKEN, NULL);
 }

 /*****************************************************************************/
 /* Manual recovery */

 vb2_error_t vb2_manual_recovery_menu(struct vb2_context *ctx)
 {
 	return ui_loop(ctx, VB2_SCREEN_RECOVERY_SELECT, try_recovery_action);
 }

 vb2_error_t try_recovery_action(struct vb2_ui_context *ui)
 {
 	int invalid_disk;
 	vb2_error_t rv = VbTryLoadKernel(ui->ctx, VB_DISK_FLAG_REMOVABLE);

 	if (rv == VB2_SUCCESS)
 		return rv;

 	/* If disk validity state changed, switch to appropriate screen. */
 	invalid_disk = rv != VB2_ERROR_LK_NO_DISK_FOUND;
 	if (invalid_disk_last != invalid_disk) {
 		invalid_disk_last = invalid_disk;
 		return change_screen(ui, invalid_disk ?
 				     VB2_SCREEN_RECOVERY_INVALID :
 				     VB2_SCREEN_RECOVERY_SELECT);
 	}

 	return VB2_REQUEST_UI_CONTINUE;
 }
	/* Copyright 2020 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.
	*
	* User interfaces for developer and recovery mode menus.
	*/

	#include "2api.h"
	#include "2common.h"
	#include "2misc.h"
	#include "2nvstorage.h"
	#include "2return_codes.h"
	#include "2secdata.h"
	#include "2ui.h"
	#include "2ui_private.h"
	#include "vboot_api.h" /* For VB_SHUTDOWN_REQUEST_POWER_BUTTON */
	#include "vboot_kernel.h"

	#define KEY_DELAY_MS 20 /* Delay between key scans in UI loops */

	/*****************************************************************************/
	/* Global variables */

	enum power_button_state power_button;
	int invalid_disk_last = -1;

	/*****************************************************************************/
	/* Utility functions */

	/**
	* Checks GBB flags against VbExIsShutdownRequested() shutdown request to
	* determine if a shutdown is required.
	*
	* @param ctx Context pointer
	* @param key Pressed key (VB_BUTTON_POWER_SHORT_PRESS)
	* @return true if a shutdown is required, or false otherwise.
	*/
	int shutdown_required(struct vb2_context *ctx, uint32_t key)
	{
	struct vb2_gbb_header *gbb = vb2_get_gbb(ctx);
	uint32_t shutdown_request = VbExIsShutdownRequested();

	/*
	* Ignore power button push until after we have seen it released.
	* This avoids shutting down immediately if the power button is still
	* being held on startup. After we've recognized a valid power button
	* push then don't report the event until after the button is released.
	*/
	if (shutdown_request & VB_SHUTDOWN_REQUEST_POWER_BUTTON) {
	shutdown_request &= ~VB_SHUTDOWN_REQUEST_POWER_BUTTON;
	if (power_button == POWER_BUTTON_RELEASED)
	power_button = POWER_BUTTON_PRESSED;
	} else {
	if (power_button == POWER_BUTTON_PRESSED)
	shutdown_request \|= VB_SHUTDOWN_REQUEST_POWER_BUTTON;
	power_button = POWER_BUTTON_RELEASED;
	}

	if (key == VB_BUTTON_POWER_SHORT_PRESS)
	shutdown_request \|= VB_SHUTDOWN_REQUEST_POWER_BUTTON;

	/* If desired, ignore shutdown request due to lid closure. */
	if (gbb->flags & VB2_GBB_FLAG_DISABLE_LID_SHUTDOWN)
	shutdown_request &= ~VB_SHUTDOWN_REQUEST_LID_CLOSED;

	/*
	* In detachables, disable shutdown due to power button.
	* It is used for menu selection instead.
	*/
	if (DETACHABLE)
	shutdown_request &= ~VB_SHUTDOWN_REQUEST_POWER_BUTTON;

	return !!shutdown_request;
	}

	/*****************************************************************************/
	/* Menu navigation actions */

	/**
	* Update selected_item, taking into account disabled indices (from
	* disabled_item_mask). The selection does not wrap, meaning that we block
	* on the 0 or max index when we hit the top or bottom of the menu.
	*/
	vb2_error_t menu_up_action(struct vb2_ui_context *ui)
	{
	int item;

	if (!DETACHABLE && ui->key == VB_BUTTON_VOL_UP_SHORT_PRESS)
	return VB2_REQUEST_UI_CONTINUE;

	item = ui->state.selected_item - 1;
	while (item >= 0 &&
	((1 << item) & ui->state.disabled_item_mask))
	item--;
	/* Only update if item is valid */
	if (item >= 0)
	ui->state.selected_item = item;

	return VB2_REQUEST_UI_CONTINUE;
	}

	vb2_error_t menu_down_action(struct vb2_ui_context *ui)
	{
	int item;

	if (!DETACHABLE && ui->key == VB_BUTTON_VOL_DOWN_SHORT_PRESS)
	return VB2_REQUEST_UI_CONTINUE;

	item = ui->state.selected_item + 1;
	while (item < ui->state.screen->num_items &&
	((1 << item) & ui->state.disabled_item_mask))
	item++;
	/* Only update if item is valid */
	if (item < ui->state.screen->num_items)
	ui->state.selected_item = item;

	return VB2_REQUEST_UI_CONTINUE;
	}

	/**
	* Navigate to the target screen of the current menu item selection.
	*/
	vb2_error_t menu_select_action(struct vb2_ui_context *ui)
	{
	const struct vb2_menu_item *menu_item;

	if (!DETACHABLE && ui->key == VB_BUTTON_POWER_SHORT_PRESS)
	return VB2_REQUEST_UI_CONTINUE;

	if (ui->state.screen->num_items == 0)
	return VB2_REQUEST_UI_CONTINUE;

	menu_item = &ui->state.screen->items[ui->state.selected_item];

	if (menu_item->action) {
	VB2_DEBUG("Menu item <%s> run action\n", menu_item->text);
	return menu_item->action(ui);
	} else if (menu_item->target) {
	VB2_DEBUG("Menu item <%s> to target screen %#x\n",
	menu_item->text, menu_item->target);
	return change_screen(ui, menu_item->target);
	}

	VB2_DEBUG("Menu item <%s> no action or target screen\n",
	menu_item->text);
	return VB2_REQUEST_UI_CONTINUE;
	}

	/**
	* Return back to the previous screen.
	*/
	vb2_error_t vb2_ui_back_action(struct vb2_ui_context *ui)
	{
	/* TODO(kitching): Return to previous screen instead of root screen. */
	return change_screen(ui, ui->root_screen->id);
	}

	/**
	* Context-dependent keyboard shortcut Ctrl+D.
	*
	* - Manual recovery mode: Change to dev mode transition screen.
	* - Developer mode: Boot from internal disk (TODO).
	*/
	vb2_error_t ctrl_d_action(struct vb2_ui_context *ui)
	{
	if (vb2_allow_recovery(ui->ctx))
	return change_screen(ui, VB2_SCREEN_RECOVERY_TO_DEV);
	return VB2_REQUEST_UI_CONTINUE;
	}

	/*****************************************************************************/
	/* Action lookup tables */

	static struct input_action action_table[] = {
	{ VB_KEY_UP, menu_up_action },
	{ VB_KEY_DOWN, menu_down_action },
	{ VB_KEY_ENTER, menu_select_action },
	{ VB_BUTTON_VOL_UP_SHORT_PRESS, menu_up_action },
	{ VB_BUTTON_VOL_DOWN_SHORT_PRESS, menu_down_action },
	{ VB_BUTTON_POWER_SHORT_PRESS, menu_select_action },
	{ VB_KEY_ESC, vb2_ui_back_action },
	{ VB_KEY_CTRL('D'), ctrl_d_action },
	{ ' ', vb2_ui_recovery_to_dev_action },
	};

	vb2_error_t (input_action_lookup(int key))(struct vb2_ui_context ui)
	{
	int i;
	for (i = 0; i < ARRAY_SIZE(action_table); i++)
	if (action_table[i].key == key)
	return action_table[i].action;
	return NULL;
	}

	/*****************************************************************************/
	/* Core UI functions */

	vb2_error_t change_screen(struct vb2_ui_context *ui, enum vb2_screen id)
	{
	const struct vb2_screen_info *new_screen_info = vb2_get_screen_info(id);

	if (new_screen_info == NULL) {
	VB2_DEBUG("ERROR: Screen entry %#x not found; ignoring\n", id);
	return VB2_REQUEST_UI_CONTINUE;
	}

	memset(&ui->state, 0, sizeof(ui->state));
	ui->state.screen = new_screen_info;

	if (ui->state.screen->init)
	return ui->state.screen->init(ui);

	return VB2_REQUEST_UI_CONTINUE;
	}

	vb2_error_t ui_loop(struct vb2_context *ctx, enum vb2_screen root_screen_id,
	vb2_error_t (global_action)(struct vb2_ui_context ui))
	{
	struct vb2_ui_context ui;
	struct vb2_screen_state prev_state;
	uint32_t key_flags;
	vb2_error_t (action)(struct vb2_ui_context ui);
	vb2_error_t rv;

	memset(&ui, 0, sizeof(ui));
	ui.ctx = ctx;
	ui.root_screen = vb2_get_screen_info(root_screen_id);
	if (ui.root_screen == NULL)
	VB2_DIE("Root screen not found.\n");
	rv = change_screen(&ui, ui.root_screen->id);
	if (rv != VB2_REQUEST_UI_CONTINUE)
	return rv;
	memset(&prev_state, 0, sizeof(prev_state));

	while (1) {
	/* Draw if there are state changes. */
	if (memcmp(&prev_state, &ui.state, sizeof(ui.state))) {
	memcpy(&prev_state, &ui.state, sizeof(ui.state));

	VB2_DEBUG("<%s> menu item <%s>\n",
	ui.state.screen->name,
	ui.state.screen->num_items ?
	ui.state.screen->items[
	ui.state.selected_item].text : "null");

	vb2ex_display_ui(ui.state.screen->id, ui.locale_id,
	ui.state.selected_item,
	ui.state.disabled_item_mask);
	}

	/* Run screen action. */
	if (ui.state.screen->action) {
	rv = ui.state.screen->action(&ui);
	if (rv != VB2_REQUEST_UI_CONTINUE)
	return rv;
	}

	/* Grab new keyboard input. */
	ui.key = VbExKeyboardReadWithFlags(&key_flags);
	ui.key_trusted = !!(key_flags & VB_KEY_FLAG_TRUSTED_KEYBOARD);

	/* Check for shutdown request. */
	if (shutdown_required(ctx, ui.key)) {
	VB2_DEBUG("Shutdown required!\n");
	return VB2_REQUEST_SHUTDOWN;
	}

	/* Run input action function if found. */
	action = input_action_lookup(ui.key);
	if (action) {
	rv = action(&ui);
	if (rv != VB2_REQUEST_UI_CONTINUE)
	return rv;
	} else if (ui.key) {
	VB2_DEBUG("Pressed key %#x, trusted? %d\n",
	ui.key, ui.key_trusted);
	}

	/* Reset keyboard input. */
	ui.key = 0;
	ui.key_trusted = 0;

	/* Run global action function if available. */
	if (global_action) {
	rv = global_action(&ui);
	if (rv != VB2_REQUEST_UI_CONTINUE)
	return rv;
	}

	/* Delay. */
	VbExSleepMs(KEY_DELAY_MS);
	}

	return VB2_SUCCESS;
	}

	/*****************************************************************************/
	/* Developer mode */

	vb2_error_t vb2_developer_menu(struct vb2_context *ctx)
	{
	enum vb2_dev_default_boot default_boot;

	/* If dev mode was disabled, loop forever. */
	if (!vb2_dev_boot_allowed(ctx))
	while (1);

	/* Boot from the default option. */
	default_boot = vb2_get_dev_boot_target(ctx);

	/* Boot legacy does not return on success */
	if (default_boot == VB2_DEV_DEFAULT_BOOT_LEGACY &&
	vb2_dev_boot_legacy_allowed(ctx) &&
	VbExLegacy(VB_ALTFW_DEFAULT) == VB2_SUCCESS)
	return VB2_SUCCESS;

	if (default_boot == VB2_DEV_DEFAULT_BOOT_USB &&
	vb2_dev_boot_usb_allowed(ctx) &&
	VbTryLoadKernel(ctx, VB_DISK_FLAG_REMOVABLE) == VB2_SUCCESS)
	return VB2_SUCCESS;

	return VbTryLoadKernel(ctx, VB_DISK_FLAG_FIXED);
	}

	/*****************************************************************************/
	/* Broken recovery */

	vb2_error_t vb2_broken_recovery_menu(struct vb2_context *ctx)
	{
	return ui_loop(ctx, VB2_SCREEN_RECOVERY_BROKEN, NULL);
	}

	/*****************************************************************************/
	/* Manual recovery */

	vb2_error_t vb2_manual_recovery_menu(struct vb2_context *ctx)
	{
	return ui_loop(ctx, VB2_SCREEN_RECOVERY_SELECT, try_recovery_action);
	}

	vb2_error_t try_recovery_action(struct vb2_ui_context *ui)
	{
	int invalid_disk;
	vb2_error_t rv = VbTryLoadKernel(ui->ctx, VB_DISK_FLAG_REMOVABLE);

	if (rv == VB2_SUCCESS)
	return rv;

	/* If disk validity state changed, switch to appropriate screen. */
	invalid_disk = rv != VB2_ERROR_LK_NO_DISK_FOUND;
	if (invalid_disk_last != invalid_disk) {
	invalid_disk_last = invalid_disk;
	return change_screen(ui, invalid_disk ?
	VB2_SCREEN_RECOVERY_INVALID :
	VB2_SCREEN_RECOVERY_SELECT);
	}

	return VB2_REQUEST_UI_CONTINUE;
	}