src/vboot/screens.c - third_party/depthcharge - Git at Google

 /*
  * Copyright 2015 Google Inc.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * 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; either version 2 of
  * the License, or (at your option) any later version.
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
  */

 #include <libpayload.h>
 #include <vboot_api.h>
 #include <vboot/screens.h>
 #include "drivers/video/display.h"

 /*
  * This is the base used to specify the size and the coordinate of the image.
  * For example, height = 40 means 4.0% of the canvas (=drawing area) height.
  */
 #define VB_SCALE	1000
 #define VB_SCALE_HALF	(VB_SCALE / 2)	/* 50.0% */

 /* Height of the text image per line relative to the canvas size */
 #define VB_TEXT_HEIGHT	40		/* 4.0% */

 /* Indicate width or height is automatically set based on the other value */
 #define VB_SIZE_AUTO	0

 /* Height of the icons relative to the canvas size */
 #define VB_ICON_HEIGHT	160

 /* Vertical position and size of the dividers */
 #define VB_DIVIDER_WIDTH	800	/* 80.0% */
 #define VB_DIVIDER_V_OFFSET	160	/* 16.0% */

 #define RETURN_ON_ERROR(function_call) do {				\
 		VbError_t rv = (function_call);				\
 		if (rv)							\
 			return rv;					\
 	} while (0)

 static char initialized = 0;

 /*
  * Locale dependent images are stored using these locale strings as a directory
  * name. For example, language.bmp for English is named en/language.bmp in cbfs.
  */
 static const char * const locale_string[] = {
 	"en",
 };

 static VbError_t draw_image(const char *image_name,
 			    int32_t x, int32_t y, int32_t width, int32_t height,
 			    char pivot)
 {
 	uint8_t *image;
 	size_t size;
 	VbError_t rv = VBERROR_SUCCESS;

 	image = load_bitmap(image_name, &size);
 	if (!image)
 		return VBERROR_NO_IMAGE_PRESENT;

 	struct scale pos = {
 		.x = { .n = x, .d = VB_SCALE, },
 		.y = { .n = y, .d = VB_SCALE, },
 	};
 	struct scale dim = {
 		.x = { .n = width, .d = VB_SCALE, },
 		.y = { .n = height, .d = VB_SCALE, },
 	};

 	rv = draw_bitmap(image, size, &pos, pivot, &dim);
 	if (rv)
 		rv = VBERROR_UNKNOWN;
 	free(image);

 	return rv;
 }

 static int draw_image_locale(const char *image_name, uint32_t locale,
 			     int32_t x, int32_t y,
 			     int32_t width, int32_t height, char pivot)
 {
 	char str[256];
 	snprintf(str, sizeof(str), "locale/%s/%s",
 		 locale_string[locale], image_name);
 	return draw_image(str, x, y, width, height, pivot);
 }

 static int draw_icon(const char *image_name)
 {
 	return draw_image(image_name,
 			  VB_SCALE_HALF, VB_SCALE_HALF,
 			  VB_SIZE_AUTO, VB_ICON_HEIGHT,
 			  PIVOT_H_CENTER|PIVOT_V_BOTTOM);
 }

 static VbError_t vboot_draw_base_screen(uint32_t locale)
 {
 	const struct rgb_color white = { 0xff, 0xff, 0xff };

 	if (clear_screen(&white))
 		return VBERROR_UNKNOWN;
 	RETURN_ON_ERROR(draw_image("chrome_logo.bmp",
 			(VB_SCALE - VB_DIVIDER_WIDTH)/2,
 			/* '-10' to keep the logo lifted up from the divider */
 			VB_DIVIDER_V_OFFSET - 10,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_LEFT|PIVOT_V_BOTTOM));
 	/*
 	 * Language section is at the top right corner. The language text image
 	 * is placed in the middle using the center as a pivot. Then, arrows
 	 * are placed on each side using PIVOT_H_RIGHT and PIVOT_H_LEFT. This
 	 * way, we can keep the different language images all in the middle.
 	 *
 	 * TODO: Get the width of the projected image and use it to determine
 	 * horizontal positions relative to the right edge of the divider.
 	 */
 	RETURN_ON_ERROR(draw_image("arrow_left.bmp",
 			770, VB_DIVIDER_V_OFFSET, VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_RIGHT|PIVOT_V_BOTTOM));
 	RETURN_ON_ERROR(draw_image_locale("language.bmp", locale,
 			820, VB_DIVIDER_V_OFFSET, VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_BOTTOM));
 	RETURN_ON_ERROR(draw_image("arrow_right.bmp",
 			870, VB_DIVIDER_V_OFFSET, VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_LEFT|PIVOT_V_BOTTOM));
 	RETURN_ON_ERROR(draw_image("divider_top.bmp",
 			VB_SCALE_HALF, VB_DIVIDER_V_OFFSET,
 			VB_DIVIDER_WIDTH, VB_SIZE_AUTO,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	RETURN_ON_ERROR(draw_image("divider_btm.bmp",
 			VB_SCALE_HALF, VB_SCALE - VB_DIVIDER_V_OFFSET,
 			VB_DIVIDER_WIDTH, VB_SIZE_AUTO,
 			PIVOT_H_CENTER|PIVOT_V_BOTTOM));

 	/*
 	 * TODO: Draw the footer. The footer consists of URL and MODEL. Both
 	 * consist of a pair of text images. Thus, to place them horizontally in
 	 * the center, we need to get the width of the projected image.
 	 */

 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_blank(uint32_t locale)
 {
 	video_console_clear();
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_developer_warning(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_icon("VerificationOff.bmp"));
 	RETURN_ON_ERROR(draw_image_locale("verif_off.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	RETURN_ON_ERROR(draw_image_locale("devmode.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF + VB_TEXT_HEIGHT,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_recovery_remove(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_image_locale("remove.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF - VB_ICON_HEIGHT,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_BOTTOM));
 	RETURN_ON_ERROR(draw_image("RemoveDevices.bmp",
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_ICON_HEIGHT * 2,
 			PIVOT_H_CENTER|PIVOT_V_CENTER));
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_recovery_no_good(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_image_locale("yuck.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_BOTTOM));
 	/*
 	 * TODO: We need a mechanism to let boards customize these. For example,
 	 * some boards have only USB.
 	 */
 	RETURN_ON_ERROR(draw_image("BadSD.bmp",
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_ICON_HEIGHT,
 			PIVOT_H_RIGHT|PIVOT_V_TOP));
 	RETURN_ON_ERROR(draw_image("BadUSB.bmp",
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_ICON_HEIGHT,
 			PIVOT_H_LEFT|PIVOT_V_TOP));
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_recovery_insert(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_icon("Warning.bmp"));
 	RETURN_ON_ERROR(draw_image_locale("insert.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT * 2,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_recovery_to_dev(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_image_locale("todev.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT * 4,
 			PIVOT_H_CENTER|PIVOT_V_CENTER));
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_developer_to_norm(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_icon("VerificationOff.bmp"));
 	RETURN_ON_ERROR(draw_image_locale("verif_off.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	RETURN_ON_ERROR(draw_image_locale("tonorm.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF + VB_TEXT_HEIGHT,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT * 3,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_wait(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_image_locale("update.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT * 3,
 			PIVOT_H_CENTER|PIVOT_V_CENTER));
 	return VBERROR_SUCCESS;
 }

 static VbError_t vboot_draw_to_norm_confirmed(uint32_t locale)
 {
 	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
 	RETURN_ON_ERROR(draw_icon("VerificationOn.bmp"));
 	RETURN_ON_ERROR(draw_image_locale("verif_on.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	RETURN_ON_ERROR(draw_image_locale("reboot_erase.bmp", locale,
 			VB_SCALE_HALF, VB_SCALE_HALF + VB_TEXT_HEIGHT,
 			VB_SIZE_AUTO, VB_TEXT_HEIGHT,
 			PIVOT_H_CENTER|PIVOT_V_TOP));
 	return VBERROR_SUCCESS;
 }

 /* we may export this in the future for the board customization */
 struct vboot_screen_descriptor {
 	uint32_t id;				/* VB_SCREEN_* */
 	VbError_t (*draw)(uint32_t locale);	/* draw function */
 	const char *mesg;			/* fallback message */
 };

 static const struct vboot_screen_descriptor vboot_screens[] = {
 	{
 		.id = VB_SCREEN_BLANK,
 		.draw = vboot_draw_blank,
 		.mesg = NULL,
 	},
 	{
 		.id = VB_SCREEN_DEVELOPER_WARNING,
 		.draw = vboot_draw_developer_warning,
 		.mesg = "OS verification is OFF\n"
 			"Press SPACE to re-enable.\n",
 	},
 	{
 		.id = VB_SCREEN_RECOVERY_REMOVE,
 		.draw = vboot_draw_recovery_remove,
 		.mesg = "Please remove all external devices to begin recovery\n",
 	},
 	{
 		.id = VB_SCREEN_RECOVERY_NO_GOOD,
 		.draw = vboot_draw_recovery_no_good,
 		.mesg = "The device you inserted does not contain Chrome OS.\n",
 	},
 	{
 		.id = VB_SCREEN_RECOVERY_INSERT,
 		.draw = vboot_draw_recovery_insert,
 		.mesg = "Chrome OS is missing or damaged.\n"
 			"Please insert a recovery USB stick or SD card.\n",
 	},
 	{
 		.id = VB_SCREEN_RECOVERY_TO_DEV,
 		.draw = vboot_draw_recovery_to_dev,
 		.mesg = "To turn OS verificaion OFF, press ENTER.\n"
 			"Your system will reboot and local data will be cleared.\n"
 			"To go back, press ESC.\n",
 	},
 	{
 		.id = VB_SCREEN_DEVELOPER_TO_NORM,
 		.draw = vboot_draw_developer_to_norm,
 		.mesg = "OS verification is OFF\n"
 			"Press ENTER to confirm you wish to turn OS verification on.\n"
 			"Your system will reboot and local data will be cleared.\n"
 			"To go back, press ESC.\n",
 	},
 	{
 		.id = VB_SCREEN_WAIT,
 		.draw = vboot_draw_wait,
 		.mesg = "Your system is applying a critical update.\n"
 			"Please do not turn off.\n",
 	},
 	{
 		.id = VB_SCREEN_TO_NORM_CONFIRMED,
 		.draw = vboot_draw_to_norm_confirmed,
 		.mesg = "OS verification is ON\n"
 			"Your system will reboot and local data will be cleared.\n",
 	},
 	{
 		.id = VB_SCREEN_OS_BROKEN,
 		.draw = NULL,
 		.mesg = "Chrome OS may be broken.\n"
 			"Remove media and initiate recovery.\n",
 	},
 };

 static const struct vboot_screen_descriptor *get_screen_descriptor(uint32_t id)
 {
 	int i;
 	for (i = 0; i < ARRAY_SIZE(vboot_screens); i++) {
 		if (vboot_screens[i].id == id)
 			return &vboot_screens[i];
 	}
 	return NULL;
 }

 static void print_fallback_message(const struct vboot_screen_descriptor *desc)
 {
 	const struct rgb_color white = { 0xff, 0xff, 0xff };
 	if (clear_screen(&white))
 		return;
 	if (desc->mesg) {
 		unsigned int rows, cols;
 		video_get_rows_cols(&rows, &cols);
 		video_console_set_cursor(0, rows/2);
 		video_printf(0, 15, VIDEO_PRINTF_ALIGN_CENTER, desc->mesg);
 	}
 }

 static VbError_t draw_screen(uint32_t screen_type, uint32_t locale)
 {
 	VbError_t rv = VBERROR_UNKNOWN;
 	const struct vboot_screen_descriptor *desc;

 	desc = get_screen_descriptor(screen_type);
 	if (!desc) {
 		printf("Not a valid screen type: 0x%x\n", screen_type);
 		return VBERROR_INVALID_SCREEN_INDEX;
 	}

 	/* if no drawing function is registered, fallback msg will be printed */
 	if (desc->draw)
 		rv = desc->draw(locale);
 	if (rv)
 		print_fallback_message(desc);

 	return rv;
 }

 static VbError_t vboot_init_display(void)
 {
 	if (display_init())
 		return VBERROR_UNKNOWN;

 	/* initialize video console */
 	video_init();
 	video_console_clear();
 	video_console_cursor_enable(0);
 	initialized = 1;

 	return VBERROR_SUCCESS;
 }

 int vboot_draw_screen(uint32_t screen)
 {
 	static uint32_t current_screen = VB_SCREEN_BLANK;
 	static uint32_t current_locale = 0;
 	/* TODO: Read locale from nvram */
 	uint32_t locale = 0;

 	printf("%s: screen=0x%x locale=%d\n", __func__, screen, locale);

 	if (!initialized) {
 		if (vboot_init_display())
 			return VBERROR_UNKNOWN;
 	}

 	if (locale > ARRAY_SIZE(locale_string)) {
 		printf("Invalid locale id = %d\n", locale);
 		return VBERROR_INVALID_PARAMETER;
 	}

 	/* If requested screen is the same as the current one, we're done. */
 	if (screen == current_screen && locale == current_locale)
 		return VBERROR_SUCCESS;

 	/* If the screen is blank, turn off the backlight; else turn it on. */
 	backlight_update(VB_SCREEN_BLANK == screen ? 0 : 1);

 	/* TODO: draw only locale dependent part if current_screen == screen */
 	RETURN_ON_ERROR(draw_screen(screen, locale));

 	current_screen = screen;
 	current_locale = locale;

 	return VBERROR_SUCCESS;
 }
	/*
	* Copyright 2015 Google Inc.
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* 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; either version 2 of
	* the License, or (at your option) any later version.
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*/

	#include <libpayload.h>
	#include <vboot_api.h>
	#include <vboot/screens.h>
	#include "drivers/video/display.h"

	/*
	* This is the base used to specify the size and the coordinate of the image.
	* For example, height = 40 means 4.0% of the canvas (=drawing area) height.
	*/
	#define VB_SCALE 1000
	#define VB_SCALE_HALF (VB_SCALE / 2) /* 50.0% */

	/* Height of the text image per line relative to the canvas size */
	#define VB_TEXT_HEIGHT 40 /* 4.0% */

	/* Indicate width or height is automatically set based on the other value */
	#define VB_SIZE_AUTO 0

	/* Height of the icons relative to the canvas size */
	#define VB_ICON_HEIGHT 160

	/* Vertical position and size of the dividers */
	#define VB_DIVIDER_WIDTH 800 /* 80.0% */
	#define VB_DIVIDER_V_OFFSET 160 /* 16.0% */

	#define RETURN_ON_ERROR(function_call) do { \
	VbError_t rv = (function_call); \
	if (rv) \
	return rv; \
	} while (0)

	static char initialized = 0;

	/*
	* Locale dependent images are stored using these locale strings as a directory
	* name. For example, language.bmp for English is named en/language.bmp in cbfs.
	*/
	static const char * const locale_string[] = {
	"en",
	};

	static VbError_t draw_image(const char *image_name,
	int32_t x, int32_t y, int32_t width, int32_t height,
	char pivot)
	{
	uint8_t *image;
	size_t size;
	VbError_t rv = VBERROR_SUCCESS;

	image = load_bitmap(image_name, &size);
	if (!image)
	return VBERROR_NO_IMAGE_PRESENT;

	struct scale pos = {
	.x = { .n = x, .d = VB_SCALE, },
	.y = { .n = y, .d = VB_SCALE, },
	};
	struct scale dim = {
	.x = { .n = width, .d = VB_SCALE, },
	.y = { .n = height, .d = VB_SCALE, },
	};

	rv = draw_bitmap(image, size, &pos, pivot, &dim);
	if (rv)
	rv = VBERROR_UNKNOWN;
	free(image);

	return rv;
	}

	static int draw_image_locale(const char *image_name, uint32_t locale,
	int32_t x, int32_t y,
	int32_t width, int32_t height, char pivot)
	{
	char str[256];
	snprintf(str, sizeof(str), "locale/%s/%s",
	locale_string[locale], image_name);
	return draw_image(str, x, y, width, height, pivot);
	}

	static int draw_icon(const char *image_name)
	{
	return draw_image(image_name,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_ICON_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_BOTTOM);
	}

	static VbError_t vboot_draw_base_screen(uint32_t locale)
	{
	const struct rgb_color white = { 0xff, 0xff, 0xff };

	if (clear_screen(&white))
	return VBERROR_UNKNOWN;
	RETURN_ON_ERROR(draw_image("chrome_logo.bmp",
	(VB_SCALE - VB_DIVIDER_WIDTH)/2,
	/* '-10' to keep the logo lifted up from the divider */
	VB_DIVIDER_V_OFFSET - 10,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_LEFT\|PIVOT_V_BOTTOM));
	/*
	* Language section is at the top right corner. The language text image
	* is placed in the middle using the center as a pivot. Then, arrows
	* are placed on each side using PIVOT_H_RIGHT and PIVOT_H_LEFT. This
	* way, we can keep the different language images all in the middle.
	*
	* TODO: Get the width of the projected image and use it to determine
	* horizontal positions relative to the right edge of the divider.
	*/
	RETURN_ON_ERROR(draw_image("arrow_left.bmp",
	770, VB_DIVIDER_V_OFFSET, VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_RIGHT\|PIVOT_V_BOTTOM));
	RETURN_ON_ERROR(draw_image_locale("language.bmp", locale,
	820, VB_DIVIDER_V_OFFSET, VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_BOTTOM));
	RETURN_ON_ERROR(draw_image("arrow_right.bmp",
	870, VB_DIVIDER_V_OFFSET, VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_LEFT\|PIVOT_V_BOTTOM));
	RETURN_ON_ERROR(draw_image("divider_top.bmp",
	VB_SCALE_HALF, VB_DIVIDER_V_OFFSET,
	VB_DIVIDER_WIDTH, VB_SIZE_AUTO,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	RETURN_ON_ERROR(draw_image("divider_btm.bmp",
	VB_SCALE_HALF, VB_SCALE - VB_DIVIDER_V_OFFSET,
	VB_DIVIDER_WIDTH, VB_SIZE_AUTO,
	PIVOT_H_CENTER\|PIVOT_V_BOTTOM));

	/*
	* TODO: Draw the footer. The footer consists of URL and MODEL. Both
	* consist of a pair of text images. Thus, to place them horizontally in
	* the center, we need to get the width of the projected image.
	*/

	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_blank(uint32_t locale)
	{
	video_console_clear();
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_developer_warning(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_icon("VerificationOff.bmp"));
	RETURN_ON_ERROR(draw_image_locale("verif_off.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	RETURN_ON_ERROR(draw_image_locale("devmode.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF + VB_TEXT_HEIGHT,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_recovery_remove(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_image_locale("remove.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF - VB_ICON_HEIGHT,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_BOTTOM));
	RETURN_ON_ERROR(draw_image("RemoveDevices.bmp",
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_ICON_HEIGHT * 2,
	PIVOT_H_CENTER\|PIVOT_V_CENTER));
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_recovery_no_good(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_image_locale("yuck.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_BOTTOM));
	/*
	* TODO: We need a mechanism to let boards customize these. For example,
	* some boards have only USB.
	*/
	RETURN_ON_ERROR(draw_image("BadSD.bmp",
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_ICON_HEIGHT,
	PIVOT_H_RIGHT\|PIVOT_V_TOP));
	RETURN_ON_ERROR(draw_image("BadUSB.bmp",
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_ICON_HEIGHT,
	PIVOT_H_LEFT\|PIVOT_V_TOP));
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_recovery_insert(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_icon("Warning.bmp"));
	RETURN_ON_ERROR(draw_image_locale("insert.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT * 2,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_recovery_to_dev(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_image_locale("todev.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT * 4,
	PIVOT_H_CENTER\|PIVOT_V_CENTER));
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_developer_to_norm(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_icon("VerificationOff.bmp"));
	RETURN_ON_ERROR(draw_image_locale("verif_off.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	RETURN_ON_ERROR(draw_image_locale("tonorm.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF + VB_TEXT_HEIGHT,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT * 3,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_wait(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_image_locale("update.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT * 3,
	PIVOT_H_CENTER\|PIVOT_V_CENTER));
	return VBERROR_SUCCESS;
	}

	static VbError_t vboot_draw_to_norm_confirmed(uint32_t locale)
	{
	RETURN_ON_ERROR(vboot_draw_base_screen(locale));
	RETURN_ON_ERROR(draw_icon("VerificationOn.bmp"));
	RETURN_ON_ERROR(draw_image_locale("verif_on.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	RETURN_ON_ERROR(draw_image_locale("reboot_erase.bmp", locale,
	VB_SCALE_HALF, VB_SCALE_HALF + VB_TEXT_HEIGHT,
	VB_SIZE_AUTO, VB_TEXT_HEIGHT,
	PIVOT_H_CENTER\|PIVOT_V_TOP));
	return VBERROR_SUCCESS;
	}

	/* we may export this in the future for the board customization */
	struct vboot_screen_descriptor {
	uint32_t id; /* VB_SCREEN_* */
	VbError_t (draw)(uint32_t locale); / draw function */
	const char mesg; / fallback message */
	};

	static const struct vboot_screen_descriptor vboot_screens[] = {
	{
	.id = VB_SCREEN_BLANK,
	.draw = vboot_draw_blank,
	.mesg = NULL,
	},
	{
	.id = VB_SCREEN_DEVELOPER_WARNING,
	.draw = vboot_draw_developer_warning,
	.mesg = "OS verification is OFF\n"
	"Press SPACE to re-enable.\n",
	},
	{
	.id = VB_SCREEN_RECOVERY_REMOVE,
	.draw = vboot_draw_recovery_remove,
	.mesg = "Please remove all external devices to begin recovery\n",
	},
	{
	.id = VB_SCREEN_RECOVERY_NO_GOOD,
	.draw = vboot_draw_recovery_no_good,
	.mesg = "The device you inserted does not contain Chrome OS.\n",
	},
	{
	.id = VB_SCREEN_RECOVERY_INSERT,
	.draw = vboot_draw_recovery_insert,
	.mesg = "Chrome OS is missing or damaged.\n"
	"Please insert a recovery USB stick or SD card.\n",
	},
	{
	.id = VB_SCREEN_RECOVERY_TO_DEV,
	.draw = vboot_draw_recovery_to_dev,
	.mesg = "To turn OS verificaion OFF, press ENTER.\n"
	"Your system will reboot and local data will be cleared.\n"
	"To go back, press ESC.\n",
	},
	{
	.id = VB_SCREEN_DEVELOPER_TO_NORM,
	.draw = vboot_draw_developer_to_norm,
	.mesg = "OS verification is OFF\n"
	"Press ENTER to confirm you wish to turn OS verification on.\n"
	"Your system will reboot and local data will be cleared.\n"
	"To go back, press ESC.\n",
	},
	{
	.id = VB_SCREEN_WAIT,
	.draw = vboot_draw_wait,
	.mesg = "Your system is applying a critical update.\n"
	"Please do not turn off.\n",
	},
	{
	.id = VB_SCREEN_TO_NORM_CONFIRMED,
	.draw = vboot_draw_to_norm_confirmed,
	.mesg = "OS verification is ON\n"
	"Your system will reboot and local data will be cleared.\n",
	},
	{
	.id = VB_SCREEN_OS_BROKEN,
	.draw = NULL,
	.mesg = "Chrome OS may be broken.\n"
	"Remove media and initiate recovery.\n",
	},
	};

	static const struct vboot_screen_descriptor *get_screen_descriptor(uint32_t id)
	{
	int i;
	for (i = 0; i < ARRAY_SIZE(vboot_screens); i++) {
	if (vboot_screens[i].id == id)
	return &vboot_screens[i];
	}
	return NULL;
	}

	static void print_fallback_message(const struct vboot_screen_descriptor *desc)
	{
	const struct rgb_color white = { 0xff, 0xff, 0xff };
	if (clear_screen(&white))
	return;
	if (desc->mesg) {
	unsigned int rows, cols;
	video_get_rows_cols(&rows, &cols);
	video_console_set_cursor(0, rows/2);
	video_printf(0, 15, VIDEO_PRINTF_ALIGN_CENTER, desc->mesg);
	}
	}

	static VbError_t draw_screen(uint32_t screen_type, uint32_t locale)
	{
	VbError_t rv = VBERROR_UNKNOWN;
	const struct vboot_screen_descriptor *desc;

	desc = get_screen_descriptor(screen_type);
	if (!desc) {
	printf("Not a valid screen type: 0x%x\n", screen_type);
	return VBERROR_INVALID_SCREEN_INDEX;
	}

	/* if no drawing function is registered, fallback msg will be printed */
	if (desc->draw)
	rv = desc->draw(locale);
	if (rv)
	print_fallback_message(desc);

	return rv;
	}

	static VbError_t vboot_init_display(void)
	{
	if (display_init())
	return VBERROR_UNKNOWN;

	/* initialize video console */
	video_init();
	video_console_clear();
	video_console_cursor_enable(0);
	initialized = 1;

	return VBERROR_SUCCESS;
	}

	int vboot_draw_screen(uint32_t screen)
	{
	static uint32_t current_screen = VB_SCREEN_BLANK;
	static uint32_t current_locale = 0;
	/* TODO: Read locale from nvram */
	uint32_t locale = 0;

	printf("%s: screen=0x%x locale=%d\n", __func__, screen, locale);

	if (!initialized) {
	if (vboot_init_display())
	return VBERROR_UNKNOWN;
	}

	if (locale > ARRAY_SIZE(locale_string)) {
	printf("Invalid locale id = %d\n", locale);
	return VBERROR_INVALID_PARAMETER;
	}

	/* If requested screen is the same as the current one, we're done. */
	if (screen == current_screen && locale == current_locale)
	return VBERROR_SUCCESS;

	/* If the screen is blank, turn off the backlight; else turn it on. */
	backlight_update(VB_SCREEN_BLANK == screen ? 0 : 1);

	/* TODO: draw only locale dependent part if current_screen == screen */
	RETURN_ON_ERROR(draw_screen(screen, locale));

	current_screen = screen;
	current_locale = locale;

	return VBERROR_SUCCESS;
	}