[PATCH 1/3] efi_loader: add menu-driven boot device selection

[Heinrich Schuchardt]

On 2/10/22 08:05, Masahisa Kojima wrote:
> This patch enables the menu-driven boot device selection.
> User can select the Boot#### included in BootOrder variable.
>
> If user quits thie menu, or the selected Boot#### fails to boot,
> efi bootmgr continues to boot in accordance with BootOrder variable.
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
>   include/efi_loader.h         |   1 +
>   lib/efi_loader/Kconfig       |  10 +
>   lib/efi_loader/efi_bootmgr.c | 557 ++++++++++++++++++++++++++++++++++-
>   3 files changed, 565 insertions(+), 3 deletions(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index e390d323a9..2c45f42dca 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -278,6 +278,7 @@ extern const efi_guid_t efi_guid_loaded_image;
>   extern const efi_guid_t efi_guid_loaded_image_device_path;
>   extern const efi_guid_t efi_guid_device_path_to_text_protocol;
>   extern const efi_guid_t efi_simple_file_system_protocol_guid;
> +extern const efi_guid_t efi_system_partition_guid;
>   extern const efi_guid_t efi_file_info_guid;
>   /* GUID for file system information */
>   extern const efi_guid_t efi_file_system_info_guid;
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index e5e35fe51f..c8108f3164 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -39,6 +39,16 @@ config CMD_BOOTEFI_BOOTMGR
>   	  via UEFI variables Boot####, BootOrder, and BootNext. This enables the
>   	  'bootefi bootmgr' command.
>
> +config EFI_BOOT_MENU
> +	bool "UEFI Boot Menu driven boot device selection"
> +	default n
> +	help
> +	  Select this option if you want to enable the menu driven boot device
> +	  selection. This menu provides the functionality to select a boot
> +	  option to start, and allow users to edit Boot#### and BootOrder.
> +	  If this menu is enabled, CLI can be disabled if the system boots
> +	  via UEFI variable Boot#### and BootOrder.
> +
>   config EFI_SETUP_EARLY
>   	bool
>
> diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> index 8c04ecbdc8..013d868f23 100644
> --- a/lib/efi_loader/efi_bootmgr.c
> +++ b/lib/efi_loader/efi_bootmgr.c
> @@ -7,13 +7,17 @@
>
>   #define LOG_CATEGORY LOGC_EFI
>
> +#include <ansi.h>
>   #include <common.h>
>   #include <charset.h>
>   #include <log.h>
>   #include <malloc.h>
> +#include <menu.h>
> +#include <watchdog.h>
>   #include <efi_loader.h>
>   #include <efi_variable.h>
>   #include <asm/unaligned.h>
> +#include <linux/delay.h>
>
>   static const struct efi_boot_services *bs;
>   static const struct efi_runtime_services *rs;
> @@ -22,14 +26,538 @@ static const struct efi_runtime_services *rs;
>    * bootmgr implements the logic of trying to find a payload to boot
>    * based on the BootOrder + BootXXXX variables, and then loading it.
>    *
> - * TODO detecting a special key held (f9?) and displaying a boot menu
> - * like you would get on a PC would be clever.
> - *
>    * TODO if we had a way to write and persist variables after the OS
>    * has started, we'd also want to check OsIndications to see if we
>    * should do normal or recovery boot.
>    */
>
> +#define EFI_BOOTMGR_MENU_ENTRY_NUM_MAX 1024
> +
> +typedef efi_status_t (*efi_bootmenu_entry_func)(void *data, bool *exit);
> +
> +/**
> + * struct efi_bootmgr_menu_entry - menu entry structure
> + *
> + * @menu_index:		menu entry index
> + * @title:		title of entry
> + * @key:		unique key
> + * @bootmgr_menu:	pointer to the menu structure
> + * @next:		pointer to the next entry
> + * @func:		callback function to be called when this entry is selected
> + * @data:		data to be passed to the callback function
> + */
> +struct efi_bootmgr_menu_entry {
> +	u32 menu_index;
> +	u16 *title;
> +	char key[6];
> +	struct efi_bootmgr_menu *bootmgr_menu;
> +	struct efi_bootmgr_menu_entry *next;
> +	efi_bootmenu_entry_func func;
> +	void *data;
> +};
> +
> +/**
> + * struct efi_bootmgr_menuy - bootmgr menu structure
> + *
> + * @delay:	delay for autoboot
> + * @active:	active menu entry index
> + * @count:	total count of menu entry
> + * @autoboot:	flag to enable autoboot
> + * @first:	pointer to the first menu entry
> + */
> +struct efi_bootmgr_menu {
> +	int delay;
> +	int active;
> +	int count;
> +	bool autoboot;
> +	struct efi_bootmgr_menu_entry *first;
> +};
> +
> +enum efi_bootmgr_menu_key {
> +	KEY_NONE = 0,
> +	KEY_UP,
> +	KEY_DOWN,
> +	KEY_SELECT,
> +	KEY_QUIT,
> +};
> +
> +struct efi_bootmgr_menu_item {
> +	u16 *title;
> +	efi_bootmenu_entry_func func;
> +	void *data;
> +};
> +
> +struct efi_bootmgr_boot_selection_data {
> +	u16 bootorder_index;
> +	void *load_option;
> +	int *selected;
> +};
> +
> +static efi_status_t efi_bootmgr_process_boot_selected(void *data, bool *exit);
> +static efi_status_t efi_bootmgr_process_boot_selection(void *data, bool *exit);
> +
> +static struct efi_bootmgr_menu_item bootmgr_menu_items[] = {
> +	{u"Boot Manager", efi_bootmgr_process_boot_selection},
> +	{u"Quit", NULL},
> +};
> +
> +static void efi_bootmgr_menu_print_entry(void *data)
> +{
> +	struct efi_bootmgr_menu_entry *entry = data;
> +	int reverse = (entry->bootmgr_menu->active == entry->menu_index);
> +
> +	/* TODO: support scroll or page for many entries */
> +
> +	/*
> +	 * Move cursor to line where the entry will be drown (entry->count)
> +	 * First 3 lines contain bootmgr menu header + one empty line
> +	 * For the last "Quit" entry, add one empty line
> +	 */
> +	if (entry->menu_index == (entry->bootmgr_menu->count - 1))
> +		printf(ANSI_CURSOR_POSITION, entry->menu_index + 5, 1);
> +	else
> +		printf(ANSI_CURSOR_POSITION, entry->menu_index + 4, 1);
> +
> +	puts("     ");
> +
> +	if (reverse)
> +		puts(ANSI_COLOR_REVERSE);
> +
> +	printf("%ls", entry->title);
> +
> +	if (reverse)
> +		puts(ANSI_COLOR_RESET);
> +}
> +
> +static void efi_bootmgr_menu_display_statusline(struct menu *m)
> +{
> +	struct efi_bootmgr_menu_entry *entry;
> +	struct efi_bootmgr_menu *bootmgr_menu;
> +
> +	if (menu_default_choice(m, (void *)&entry) < 0)
> +		return;
> +
> +	bootmgr_menu = entry->bootmgr_menu;
> +
> +	printf(ANSI_CURSOR_POSITION, 1, 1);
> +	puts(ANSI_CLEAR_LINE);
> +	printf(ANSI_CURSOR_POSITION, 2, 1);
> +	puts("  *** U-Boot EFI Boot Manager ***");
> +	puts(ANSI_CLEAR_LINE_TO_END);
> +	printf(ANSI_CURSOR_POSITION, 3, 1);
> +	puts(ANSI_CLEAR_LINE);
> +
> +	/* First 3 lines are bootmgr_menu header + 2 empty lines between entries */
> +	printf(ANSI_CURSOR_POSITION, bootmgr_menu->count + 5, 1);
> +	puts(ANSI_CLEAR_LINE);
> +	printf(ANSI_CURSOR_POSITION, bootmgr_menu->count + 6, 1);
> +	puts("  Press UP/DOWN to move, ENTER to select, ESC/CTRL+C to quit");
> +	puts(ANSI_CLEAR_LINE_TO_END);
> +	printf(ANSI_CURSOR_POSITION, bootmgr_menu->count + 7, 1);
> +	puts(ANSI_CLEAR_LINE);
> +}
> +
> +static void efi_bootmgr_menu_autoboot_loop(struct efi_bootmgr_menu *bootmgr_menu,
> +					   enum efi_bootmgr_menu_key *key, int *esc)
> +{
> +	int i, c;
> +
> +	if (bootmgr_menu->delay > 0) {
> +		printf(ANSI_CURSOR_POSITION, bootmgr_menu->count + 5, 1);
> +		printf("  Hit any key to stop autoboot: %2d ", bootmgr_menu->delay);
> +	}
> +
> +	while (bootmgr_menu->delay > 0) {
> +		for (i = 0; i < 100; ++i) {

Should the keyboard buffer be drained before asking the question?

> +			if (!tstc()) {
> +				WATCHDOG_RESET();
> +				mdelay(10);
> +				continue;
> +			}
> +
> +			bootmgr_menu->delay = -1;
> +			c = getchar();
> +
> +			switch (c) {
> +			case '\e':
> +				*esc = 1;
> +				*key = KEY_NONE;
> +				break;
> +			case '\r':
> +				*key = KEY_SELECT;
> +				break;
> +			case 0x3: /* ^C */
> +				*key = KEY_QUIT;
> +				break;
> +			default:
> +				*key = KEY_NONE;
> +				break;
> +			}
> +

Don't duplicate bootmenu_autoboot_loop(). Instead move it to a library
function.


> +			break;
> +		}
> +
> +		if (bootmgr_menu->delay < 0)
> +			break;
> +
> +		--bootmgr_menu->delay;
> +		printf("\b\b\b%2d ", bootmgr_menu->delay);
> +	}
> +
> +	printf(ANSI_CURSOR_POSITION, bootmgr_menu->count + 5, 1);
> +	puts(ANSI_CLEAR_LINE);
> +
> +	if (bootmgr_menu->delay == 0)
> +		*key = KEY_QUIT;
> +}
> +
> +static void efi_bootmgr_menu_loop(struct efi_bootmgr_menu *bootmgr_menu,
> +				  enum efi_bootmgr_menu_key *key, int *esc)
> +{

Don't create duplicate code. Just reuse bootmenu_autoboot_loop().

> +	int c;
> +
> +	if (*esc == 1) {
> +		if (tstc()) {
> +			c = getchar();
> +		} else {
> +			WATCHDOG_RESET();
> +			mdelay(10);
> +			if (tstc())
> +				c = getchar();
> +			else
> +				c = '\e';
> +		}
> +	} else {
> +		while (!tstc()) {
> +			WATCHDOG_RESET();
> +			mdelay(10);
> +		}
> +		c = getchar();
> +	}
> +
> +	switch (*esc) {
> +	case 0:
> +		/* First char of ANSI escape sequence '\e' */
> +		if (c == '\e') {
> +			*esc = 1;
> +			*key = KEY_NONE;
> +		}
> +		break;
> +	case 1:
> +		/* Second char of ANSI '[' */
> +		if (c == '[') {
> +			*esc = 2;
> +			*key = KEY_NONE;
> +		} else {
> +		/* Alone ESC key was pressed */
> +			*key = KEY_QUIT;
> +			*esc = (c == '\e') ? 1 : 0;
> +		}
> +		break;
> +	case 2:
> +	case 3:
> +		/* Third char of ANSI (number '1') - optional */
> +		if (*esc == 2 && c == '1') {
> +			*esc = 3;
> +			*key = KEY_NONE;
> +			break;
> +		}
> +
> +		*esc = 0;
> +
> +		/* ANSI 'A' - key up was pressed */
> +		if (c == 'A')
> +			*key = KEY_UP;
> +		/* ANSI 'B' - key down was pressed */
> +		else if (c == 'B')
> +			*key = KEY_DOWN;
> +		/* other key was pressed */
> +		else
> +			*key = KEY_NONE;
> +
> +		break;
> +	}
> +
> +	/* enter key was pressed */
> +	if (c == '\r')
> +		*key = KEY_SELECT;
> +
> +	/* ^C was pressed */
> +	if (c == 0x3)
> +		*key = KEY_QUIT;
> +}
> +
> +static char *efi_bootmgr_menu_choice_entry(void *data)
> +{
> +	int i;
> +	int esc = 0;
> +	struct efi_bootmgr_menu_entry *iter;
> +	enum efi_bootmgr_menu_key key = KEY_NONE;
> +	struct efi_bootmgr_menu *bootmgr_menu = data;
> +
> +	while (1) {
> +		if (bootmgr_menu->delay >= 0 && bootmgr_menu->autoboot) {
> +			/* Autoboot was not stopped */
> +			efi_bootmgr_menu_autoboot_loop(bootmgr_menu, &key, &esc);
> +		} else {
> +			/* Some key was pressed, so autoboot was stopped */
> +			efi_bootmgr_menu_loop(bootmgr_menu, &key, &esc);
> +		}
> +
> +		switch (key) {
> +		case KEY_UP:
> +			if (bootmgr_menu->active > 0)
> +				--bootmgr_menu->active;
> +			/* no menu key selected, regenerate menu */
> +			return NULL;

Don't duplicate what we already have in cmd/bootmenu.c

Best regards

Heinrich

> +		case KEY_DOWN:
> +			if (bootmgr_menu->active < bootmgr_menu->count - 1)
> +				++bootmgr_menu->active;
> +			/* no menu key selected, regenerate menu */
> +			return NULL;
> +		case KEY_SELECT:
> +			iter = bootmgr_menu->first;
> +			for (i = 0; i < bootmgr_menu->active; ++i)
> +				iter = iter->next;
> +			return iter->key;
> +		case KEY_QUIT:
> +			/* Quit by choosing the last entry */
> +			iter = bootmgr_menu->first;
> +			while (iter->next)
> +				iter = iter->next;
> +			return iter->key;
> +		default:
> +			break;
> +		}
> +	}
> +
> +	/* never happens */
> +	debug("bootmgr menu: this should not happen");
> +	return NULL;
> +}
> +
> +static void efi_bootmgr_menu_destroy(struct efi_bootmgr_menu *bootmgr_menu)
> +{
> +	struct efi_bootmgr_menu_entry *next;
> +	struct efi_bootmgr_menu_entry *iter = bootmgr_menu->first;
> +
> +	while (iter) {
> +		next = iter->next;
> +		free(iter);
> +		iter = next;
> +	}
> +	free(bootmgr_menu);
> +}
> +
> +/**
> + * efi_bootmgr_process_common() - main handler for uefi bootmgr menu
> + *
> + * Construct the structures required to show the menu, then handle
> + * the user input intracting with u-boot menu functions.
> + *
> + * @items:	pointer to the structure of each menu entry
> + * @count:	the number of menu entry
> + * @autoboot:	flag to enable autoboot
> + * Return:	status code
> + */
> +static efi_status_t efi_bootmgr_process_common(struct efi_bootmgr_menu_item *items,
> +					       int count, bool autoboot)
> +{
> +	u32 i;
> +	bool exit = false;
> +	efi_status_t ret;
> +	struct menu *menu;
> +	void *choice = NULL;
> +	struct efi_bootmgr_menu_entry *entry;
> +	struct efi_bootmgr_menu *bootmgr_menu;
> +	struct efi_bootmgr_menu_entry *iter = NULL;
> +
> +	if (count > EFI_BOOTMGR_MENU_ENTRY_NUM_MAX)
> +		return EFI_OUT_OF_RESOURCES;
> +
> +	bootmgr_menu = calloc(1, sizeof(struct efi_bootmgr_menu));
> +	if (!bootmgr_menu)
> +		return EFI_OUT_OF_RESOURCES;
> +
> +	bootmgr_menu->delay = 20; /* TODO: get from u-boot variable */
> +	bootmgr_menu->active = 0;
> +	bootmgr_menu->autoboot = autoboot;
> +	bootmgr_menu->first = NULL;
> +
> +	for (i = 0; i < count; i++) {
> +		entry = calloc(1, sizeof(struct efi_bootmgr_menu_entry));
> +		if (!entry) {
> +			ret = EFI_LOAD_ERROR;
> +			goto out;
> +		}
> +
> +		entry->menu_index = i;
> +		entry->title = items->title;
> +		snprintf(entry->key, sizeof(entry->key), "%04X", i);
> +		entry->bootmgr_menu = bootmgr_menu;
> +		entry->func = items->func;
> +		entry->data = items->data;
> +		entry->next = NULL;
> +
> +		if (!iter)
> +			bootmgr_menu->first = entry;
> +		else
> +			iter->next = entry;
> +
> +		iter = entry;
> +		items++;
> +	}
> +	bootmgr_menu->count = count;
> +
> +	menu = menu_create(NULL, bootmgr_menu->delay, 1, efi_bootmgr_menu_display_statusline,
> +			   efi_bootmgr_menu_print_entry, efi_bootmgr_menu_choice_entry,
> +			   bootmgr_menu);
> +	if (!menu) {
> +		ret = EFI_INVALID_PARAMETER;
> +		goto out;
> +	}
> +
> +	for (entry = bootmgr_menu->first; entry; entry = entry->next) {
> +		if (!menu_item_add(menu, entry->key, entry)) {
> +			ret = EFI_INVALID_PARAMETER;
> +			goto out;
> +		}
> +	}
> +
> +	menu_default_set(menu, bootmgr_menu->first->key);
> +
> +	while (!exit) {
> +		puts(ANSI_CURSOR_HIDE);
> +		puts(ANSI_CLEAR_CONSOLE);
> +		printf(ANSI_CURSOR_POSITION, 1, 1);
> +
> +		if (menu_get_choice(menu, &choice)) {
> +			entry = choice;
> +			if (entry->func)
> +				ret = entry->func(entry->data, &exit);
> +
> +			/* last entry "Quit" is selected, exit this menu */
> +			if (entry->menu_index == (entry->bootmgr_menu->count - 1)) {
> +				ret = EFI_ABORTED;
> +				break;
> +			}
> +		}
> +	}
> +
> +out:
> +	menu_destroy(menu);
> +	efi_bootmgr_menu_destroy(bootmgr_menu);
> +
> +	puts(ANSI_CURSOR_HIDE);
> +	puts(ANSI_CLEAR_CONSOLE);
> +	printf(ANSI_CURSOR_POSITION, 1, 1);
> +
> +	return ret;
> +}
> +
> +static efi_status_t efi_bootmgr_show_boot_selection(u16 *bootorder, efi_uintn_t count,
> +						    int *selected)
> +{
> +	u32 i;
> +	efi_status_t ret;
> +	efi_uintn_t size;
> +	void *load_option;
> +	struct efi_load_option lo;
> +	u16 varname[] = u"Boot####";
> +	struct efi_bootmgr_menu_item *menu_item, *iter;
> +
> +	menu_item = calloc(count + 1, sizeof(struct efi_bootmgr_menu_item));
> +	if (!menu_item) {
> +		ret = EFI_OUT_OF_RESOURCES;
> +		goto out;
> +	}
> +
> +	iter = menu_item;
> +	for (i = 0; i < count; i++) {
> +		efi_create_indexed_name(varname, sizeof(varname),
> +					"Boot", bootorder[i]);
> +		load_option = efi_get_var(varname, &efi_global_variable_guid, &size);
> +		if (!load_option)
> +			continue;
> +
> +		ret = efi_deserialize_load_option(&lo, load_option, &size);
> +		if (ret != EFI_SUCCESS) {
> +			log_warning("Invalid load option for %ls\n", varname);
> +			free(load_option);
> +			continue;
> +		}
> +
> +		if (lo.attributes & LOAD_OPTION_ACTIVE) {
> +			struct efi_bootmgr_boot_selection_data *info;
> +
> +			info = calloc(1, sizeof(struct efi_bootmgr_boot_selection_data));
> +			if (!info) {
> +				ret = EFI_OUT_OF_RESOURCES;
> +				goto out;
> +			}
> +
> +			info->bootorder_index = i;
> +			info->load_option = load_option;
> +			info->selected = selected;
> +			iter->title = lo.label;
> +			iter->func = efi_bootmgr_process_boot_selected;
> +			iter->data = info;
> +			iter++;
> +		}
> +	}
> +
> +	/* add "Quit" entry */
> +	iter->title = u"Quit";
> +	iter->func = NULL;
> +	iter->data = NULL;
> +	count += 1;
> +
> +	ret = efi_bootmgr_process_common(menu_item, count, false);
> +
> +out:
> +	iter = menu_item;
> +	for (i = 0; i < count - 1; i++, iter++) {
> +		free(((struct efi_bootmgr_boot_selection_data *)iter->data)->load_option);
> +		free(iter->data);
> +	}
> +
> +	free(menu_item);
> +
> +	return ret;
> +}
> +
> +static efi_status_t efi_bootmgr_process_boot_selected(void *data, bool *exit)
> +{
> +	struct efi_bootmgr_boot_selection_data *info = data;
> +
> +	*exit = true;
> +
> +	if (info)
> +		*info->selected = info->bootorder_index;
> +
> +	return EFI_SUCCESS;
> +}
> +
> +static efi_status_t efi_bootmgr_process_boot_selection(void *data, bool *exit)
> +{
> +	u16 *bootorder;
> +	efi_status_t ret;
> +	efi_uintn_t num, size;
> +
> +	bootorder = efi_get_var(L"BootOrder", &efi_global_variable_guid, &size);
> +	if (!bootorder)
> +		return EFI_NOT_FOUND;
> +
> +	num = size / sizeof(u16);
> +	ret = efi_bootmgr_show_boot_selection(bootorder, num, data);
> +	if (ret == EFI_SUCCESS)
> +		*exit =  true;
> +
> +	free(bootorder);
> +
> +	return ret;
> +}
> +
>   /**
>    * try_load_entry() - try to load image for boot option
>    *
> @@ -177,6 +705,29 @@ efi_status_t efi_bootmgr_load(efi_handle_t *handle, void **load_options)
>   		}
>   	}
>
> +	if (IS_ENABLED(CONFIG_EFI_BOOT_MENU)) {
> +		int selected;
> +
> +		bootmgr_menu_items[0].data = &selected;
> +		ret = efi_bootmgr_process_common(bootmgr_menu_items,
> +						 ARRAY_SIZE(bootmgr_menu_items),
> +						 true);
> +		if (ret == EFI_SUCCESS) {
> +			/* bootorder may be updated in the bootmgr menu */
> +			bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &size);
> +			if (!bootorder) {
> +				log_info("BootOrder not defined\n");
> +				goto error;
> +			}
> +			ret = try_load_entry(bootorder[selected], handle, load_options);
> +			if (ret == EFI_SUCCESS)
> +				return ret;
> +
> +			log_err("Failed to start the selected entry(Boot%04X)\n",
> +				bootorder[selected]);
> +		}
> +	}
> +
>   	/* BootOrder */
>   	bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &size);
>   	if (!bootorder) {