[v6,4/6] bootmenu: add removable media entries

diff --git a/cmd/bootmenu.c b/cmd/bootmenu.c
index 4b846332b0..911086c97e 100644
--- a/cmd/bootmenu.c
+++ b/cmd/bootmenu.c
@@ -234,6 +234,89 @@  static int prepare_bootmenu_entry(struct bootmenu_data *menu,
 	return 1;
 }
 
+/**
+ * prepare_media_device_entry() - generate the media device entries
+ *
+ * This function enumerates all devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
+ * and generate the bootmenu entries.
+ * This function also provide the BOOT#### variable maintenance for
+ * the media device entries.
+ *   - Automatically create the BOOT#### variable for the newly detected device,
+ *     this BOOT#### variable is distinguished by the special GUID
+ *     stored in the EFI_LOAD_OPTION.optional_data
+ *   - If the device is not attached to the system, the associated BOOT#### variable
+ *     is automatically deleted.
+ *
+ * Return:	status code
+ */
+static efi_status_t prepare_media_device_entry(void)
+{
+	u32 i;
+	efi_status_t ret;
+	efi_uintn_t count;
+	efi_handle_t *volume_handles = NULL;
+	struct efi_bootmenu_media_boot_option *opt = NULL;
+
+	ret = efi_locate_handle_buffer_int(BY_PROTOCOL, &efi_simple_file_system_protocol_guid,
+					   NULL, &count, (efi_handle_t **)&volume_handles);
+	if (ret != EFI_SUCCESS)
+		return ret;
+
+	opt = calloc(count, sizeof(struct efi_bootmenu_media_boot_option));
+	if (!opt)
+		goto out;
+
+	/* enumerate all devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL */
+	ret = efi_bootmenu_enumerate_boot_option(opt, volume_handles, count);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	/*
+	 * System hardware configuration may vary depending on the user setup.
+	 * The boot option is automatically added by the bootmenu.
+	 * If the device is not attached to the system, the boot option needs
+	 * to be deleted.
+	 */
+	ret = efi_bootmenu_delete_invalid_boot_option(opt, count);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	/* add non-existent boot option */
+	for (i = 0; i < count; i++) {
+		u32 boot_index;
+		u16 var_name[9];
+
+		if (!opt[i].exist) {
+			ret = efi_bootmenu_get_unused_bootoption(var_name, sizeof(var_name),
+								 &boot_index);
+			if (ret != EFI_SUCCESS)
+				goto out;
+
+			ret = efi_set_variable_int(var_name, &efi_global_variable_guid,
+						   EFI_VARIABLE_NON_VOLATILE |
+						   EFI_VARIABLE_BOOTSERVICE_ACCESS |
+						   EFI_VARIABLE_RUNTIME_ACCESS,
+						   opt[i].size, opt[i].lo, false);
+			if (ret != EFI_SUCCESS)
+				goto out;
+
+			ret = efi_bootmenu_append_bootorder(boot_index);
+			if (ret != EFI_SUCCESS)
+				goto out;
+		}
+	}
+
+out:
+	if (opt) {
+		for (i = 0; i < count; i++)
+			free(opt[i].lo);
+	}
+	free(opt);
+	efi_free_pool(volume_handles);
+
+	return ret;
+}
+
 /**
  * prepare_uefi_bootorder_entry() - generate the uefi bootmenu entries
  *
@@ -326,6 +409,7 @@  static int prepare_uefi_bootorder_entry(struct bootmenu_data *menu,
 static struct bootmenu_data *bootmenu_create(int delay)
 {
 	int ret;
+	efi_status_t efi_ret;
 	unsigned short int i = 0;
 	struct bootmenu_data *menu;
 	struct bootmenu_entry *iter = NULL;
@@ -349,6 +433,16 @@  static struct bootmenu_data *bootmenu_create(int delay)
 		goto cleanup;
 
 	if (IS_ENABLED(CONFIG_CMD_BOOTEFI_BOOTMGR) && IS_ENABLED(CONFIG_AUTOBOOT_MENU_SHOW)) {
+		if (i < MAX_DYNAMIC_ENTRY) {
+			/*
+			 * UEFI specification requires booting from removal media using
+			 * a architecture-specific default image name such as BOOTAA64.EFI.
+			 */
+			efi_ret = prepare_media_device_entry();
+			if (efi_ret != EFI_SUCCESS && efi_ret != EFI_NOT_FOUND)
+				goto cleanup;
+		}
+
 		if (i < MAX_DYNAMIC_ENTRY) {
 			ret = prepare_uefi_bootorder_entry(menu, &iter, &i);
 			if (ret < 0 && ret != -ENOENT)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 49f326e585..48485e8da9 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -252,6 +252,9 @@  extern const struct efi_hii_string_protocol efi_hii_string;
 
 uint16_t *efi_dp_str(struct efi_device_path *dp);
 
+/* GUID for the auto generated boot menu entry */
+extern const efi_guid_t efi_guid_bootmenu_auto_generated;
+
 /* GUID of the U-Boot root node */
 extern const efi_guid_t efi_u_boot_guid;
 #ifdef CONFIG_SANDBOX
@@ -934,6 +937,22 @@  struct efi_signature_store {
 struct x509_certificate;
 struct pkcs7_message;
 
+/**
+ * struct efi_bootmenu_media_boot_option - boot option for (removable) media device
+ *
+ * This structure is used to enumerate possible boot option
+ *
+ * @lo:		Serialized load option data
+ * @size:	Size of serialized load option data
+ * @exist:	Flag to indicate the load option already exists
+ *		in Non-volatile load option
+ */
+struct efi_bootmenu_media_boot_option {
+	void *lo;
+	efi_uintn_t size;
+	bool exist;
+};
+
 bool efi_signature_lookup_digest(struct efi_image_regions *regs,
 				 struct efi_signature_store *db,
 				 bool dbx);
@@ -1082,6 +1101,10 @@  efi_status_t efi_console_get_u16_string
 efi_status_t efi_bootmenu_get_unused_bootoption(u16 *buf,
 						efi_uintn_t buf_size, u32 *index);
 efi_status_t efi_bootmenu_append_bootorder(u16 index);
+efi_status_t efi_bootmenu_enumerate_boot_option(struct efi_bootmenu_media_boot_option *opt,
+						efi_handle_t *volume_handles, efi_status_t count);
+efi_status_t efi_bootmenu_delete_invalid_boot_option(struct efi_bootmenu_media_boot_option *opt,
+						     efi_status_t count);
 
 efi_status_t efi_disk_get_device_name(struct efi_block_io *this, char *buf, int size);
 
diff --git a/lib/efi_loader/efi_bootmenu_maintenance.c b/lib/efi_loader/efi_bootmenu_maintenance.c
index be67fca95f..58f2999c61 100644
--- a/lib/efi_loader/efi_bootmenu_maintenance.c
+++ b/lib/efi_loader/efi_bootmenu_maintenance.c
@@ -26,6 +26,13 @@  static struct efi_simple_text_output_protocol *cout;
 #define EFI_BOOTMENU_BOOT_NAME_MAX 32
 #define EFI_BOOT_ORDER_MAX_SIZE_IN_DECIMAL 6
 
+#define EFI_BOOTMENU_AUTO_GENERATED_ENTRY_GUID \
+	EFI_GUID(0x38c1acc1, 0x9fc0, 0x41f0, \
+		 0xb9, 0x01, 0xfa, 0x74, 0xd6, 0xd6, 0xe4, 0xde)
+
+const efi_guid_t efi_guid_bootmenu_auto_generated =
+		EFI_BOOTMENU_AUTO_GENERATED_ENTRY_GUID;
+
 typedef efi_status_t (*efi_bootmenu_entry_func)(void *data, bool *exit);
 
 /**
@@ -1142,3 +1149,134 @@  efi_status_t efi_bootmenu_show_maintenance_menu(void)
 					  ARRAY_SIZE(maintenance_menu_items),
 					  -1);
 }
+
+efi_status_t efi_bootmenu_enumerate_boot_option(struct efi_bootmenu_media_boot_option *opt,
+						efi_handle_t *volume_handles, efi_status_t count)
+{
+	u32 i;
+	struct efi_handler *handler;
+	efi_status_t ret = EFI_SUCCESS;
+
+	for (i = 0; i < count; i++) {
+		char *optional_data;
+		u16 *dev_name, *p;
+		struct efi_load_option lo;
+		struct efi_block_io *block_io;
+		char buf[BOOTMENU_DEVICE_NAME_MAX];
+		struct efi_device_path *device_path;
+
+		ret = efi_search_protocol(volume_handles[i], &efi_guid_device_path, &handler);
+		if (ret != EFI_SUCCESS)
+			continue;
+		ret = efi_protocol_open(handler, (void **)&device_path,
+					efi_root, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+		if (ret != EFI_SUCCESS)
+			continue;
+
+		ret = efi_search_protocol(volume_handles[i], &efi_block_io_guid, &handler);
+		if (ret != EFI_SUCCESS)
+			continue;
+		ret = efi_protocol_open(handler, (void **)&block_io,
+					efi_root, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+		if (ret != EFI_SUCCESS)
+			continue;
+
+		efi_disk_get_device_name(block_io, buf, BOOTMENU_DEVICE_NAME_MAX);
+		dev_name = calloc(1, (strlen(buf) + 1) * sizeof(u16));
+		if (!dev_name) {
+			ret = EFI_OUT_OF_RESOURCES;
+			goto out;
+		}
+		p = dev_name;
+		utf8_utf16_strncpy(&p, buf, strlen(buf));
+
+		lo.label = dev_name;
+		lo.attributes = LOAD_OPTION_ACTIVE;
+		lo.file_path = device_path;
+		lo.file_path_length = efi_dp_size(device_path) + sizeof(END);
+		/*
+		 * Set the dedicated guid to optional_data, it is used to identify
+		 * the boot option that automatically generated by the bootmenu.
+		 * efi_serialize_load_option() expects optional_data is null-terminated
+		 * utf8 string, so set the "1234567" string to allocate enough space
+		 * to store guid, instead of realloc the load_option.
+		 */
+		lo.optional_data = "1234567";
+		opt[i].size = efi_serialize_load_option(&lo, (u8 **)&opt[i].lo);
+		if (!opt[i].size) {
+			ret = EFI_OUT_OF_RESOURCES;
+			free(dev_name);
+			goto out;
+		}
+		/* set the guid */
+		optional_data = (char *)opt[i].lo + (opt[i].size - u16_strsize(u"1234567"));
+		memcpy(optional_data, &efi_guid_bootmenu_auto_generated, sizeof(efi_guid_t));
+		free(dev_name);
+	}
+
+out:
+	return ret;
+}
+
+efi_status_t efi_bootmenu_delete_invalid_boot_option(struct efi_bootmenu_media_boot_option *opt,
+						     efi_status_t count)
+{
+	u16 *bootorder;
+	u32 i, j;
+	efi_status_t ret;
+	efi_uintn_t num, size, bootorder_size;
+	void *load_option;
+	struct efi_load_option lo;
+	u16 varname[] = u"Boot####";
+
+	bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &bootorder_size);
+	if (!bootorder)
+		return EFI_SUCCESS; /* BootOrder is not defined, nothing to do */
+
+	num = bootorder_size / sizeof(u16);
+	for (i = 0; i < num;) {
+		efi_uintn_t tmp;
+
+		efi_create_indexed_name(varname, sizeof(varname),
+					"Boot", bootorder[i]);
+		load_option = efi_get_var(varname, &efi_global_variable_guid, &size);
+		if (!load_option)
+			goto next;
+
+		tmp = size;
+		ret = efi_deserialize_load_option(&lo, load_option, &size);
+		if (ret != EFI_SUCCESS)
+			goto next;
+
+		if (size >= sizeof(efi_guid_bootmenu_auto_generated)) {
+			if (guidcmp(lo.optional_data, &efi_guid_bootmenu_auto_generated) == 0) {
+				for (j = 0; j < count; j++) {
+					if (opt[j].size == tmp &&
+					    memcmp(opt[j].lo, load_option, tmp) == 0) {
+						opt[j].exist = true;
+						break;
+					}
+				}
+
+				if (j == count) {
+					ret = delete_boot_option(bootorder, i, bootorder_size);
+					if (ret != EFI_SUCCESS) {
+						free(load_option);
+						goto out;
+					}
+
+					num--;
+					bootorder_size -= sizeof(u16);
+					free(load_option);
+					continue;
+				}
+			}
+		}
+next:
+		free(load_option);
+		i++;
+	}
+
+out:
+	return ret;
+}
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 631a25d76e..ca2fbd26ce 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -146,6 +146,10 @@  static efi_status_t try_load_entry(u16 n, efi_handle_t *handle,
 	}
 
 	/* Set load options */
+	if (size >= sizeof(efi_guid_t) &&
+	    !guidcmp(lo.optional_data, &efi_guid_bootmenu_auto_generated))
+		size = 0;
+
 	if (size) {
 		*load_options = malloc(size);
 		if (!*load_options) {