[U-Boot] [PATCH v4 01/13] Add generic, reusable menu code
Jason Hobbs
jason.hobbs at calxeda.com
Tue Aug 23 23:06:49 CEST 2011
This will be used first by the pxe code, but is intended to be
generic and reusable for other jobs in U-boot.
Signed-off-by: Jason Hobbs <jason.hobbs at calxeda.com>
---
changes in v2:
- new in v2
changes in v3:
- move timeout support to later patch
- fix NULL case bug in menu_item_key_match
- consistently use 'item_key' instead of 'key'
- move default/prompt logic into menu code
- consistently return int for error propagation
- change option setting functions to menu_create parameters
- add README.menu
changes in v4:
- change pxecfg to pxe in commit log
- improve the menu documentation
common/Makefile | 1 +
common/menu.c | 393 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
doc/README.menu | 119 +++++++++++++++++
include/menu.h | 30 ++++
4 files changed, 543 insertions(+), 0 deletions(-)
create mode 100644 common/menu.c
create mode 100644 doc/README.menu
create mode 100644 include/menu.h
diff --git a/common/Makefile b/common/Makefile
index d662468..ebe45b8 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -169,6 +169,7 @@ COBJS-$(CONFIG_CMD_KGDB) += kgdb.o kgdb_stubs.o
COBJS-$(CONFIG_KALLSYMS) += kallsyms.o
COBJS-$(CONFIG_LCD) += lcd.o
COBJS-$(CONFIG_LYNXKDI) += lynxkdi.o
+COBJS-$(CONFIG_MENU) += menu.o
COBJS-$(CONFIG_MODEM_SUPPORT) += modem.o
COBJS-$(CONFIG_UPDATE_TFTP) += update.o
COBJS-$(CONFIG_USB_KEYBOARD) += usb_kbd.o
diff --git a/common/menu.c b/common/menu.c
new file mode 100644
index 0000000..5643937
--- /dev/null
+++ b/common/menu.c
@@ -0,0 +1,393 @@
+/*
+ * Copyright 2010-2011 Calxeda, 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; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <errno.h>
+#include <linux/list.h>
+
+#include "menu.h"
+
+/*
+ * Internally, each item in a menu is represented by a struct menu_item.
+ *
+ * These items will be alloc'd and initialized by menu_item_add and destroyed
+ * by menu_item_destroy, and the consumer of the interface never sees that
+ * this struct is used at all.
+ */
+struct menu_item {
+ char *key;
+ void *data;
+ struct list_head list;
+};
+
+/*
+ * The menu is composed of a list of items along with settings and callbacks
+ * provided by the user. An incomplete definition of this struct is available
+ * in menu.h, but the full definition is here to prevent consumers from
+ * relying on its contents.
+ */
+struct menu {
+ struct menu_item *default_item;
+ char *title;
+ int prompt;
+ void (*item_data_print)(void *);
+ struct list_head items;
+};
+
+/*
+ * An iterator function for menu items. callback will be called for each item
+ * in m, with m, a pointer to the item, and extra being passed to callback. If
+ * callback returns a value other than NULL, iteration stops and the value
+ * return by callback is returned from menu_items_iter. This allows it to be
+ * used for search type operations. It is also safe for callback to remove the
+ * item from the list of items.
+ */
+static inline void *menu_items_iter(struct menu *m,
+ void *(*callback)(struct menu *, struct menu_item *, void *),
+ void *extra)
+{
+ struct list_head *pos, *n;
+ struct menu_item *item;
+ void *ret;
+
+ list_for_each_safe(pos, n, &m->items) {
+ item = list_entry(pos, struct menu_item, list);
+
+ ret = callback(m, item, extra);
+
+ if (ret)
+ return ret;
+ }
+
+ return NULL;
+}
+
+/*
+ * Print a menu_item. If the consumer provided an item_data_print function
+ * when creating the menu, call it with a pointer to the item's private data.
+ * Otherwise, print the key of the item.
+ */
+static inline void *menu_item_print(struct menu *m,
+ struct menu_item *item,
+ void *extra)
+{
+ if (!m->item_data_print)
+ printf("%s\n", item->key);
+ else
+ m->item_data_print(item->data);
+
+ return NULL;
+}
+
+/*
+ * Free the memory used by a menu item. This includes the memory used by its
+ * key.
+ */
+static inline void *menu_item_destroy(struct menu *m,
+ struct menu_item *item,
+ void *extra)
+{
+ if (item->key)
+ free(item->key);
+
+ free(item);
+
+ return NULL;
+}
+
+/*
+ * Display a menu so the user can make a choice of an item. First display its
+ * title, if any, and then each item in the menu.
+ */
+static inline void menu_display(struct menu *m)
+{
+ if (m->title)
+ printf("%s:\n", m->title);
+
+ menu_items_iter(m, menu_item_print, NULL);
+}
+
+/*
+ * Check if an item's key matches a provided string, pointed to by extra. If
+ * extra is NULL, an item with a NULL key will match. Otherwise, the item's
+ * key has to match according to strcmp.
+ *
+ * This is called via menu_items_iter, so it returns a pointer to the item if
+ * the key matches, and returns NULL otherwise.
+ */
+static inline void *menu_item_key_match(struct menu *m,
+ struct menu_item *item, void *extra)
+{
+ char *item_key = extra;
+
+ if (!item_key || !item->key) {
+ if (item_key == item->key)
+ return item;
+
+ return NULL;
+ }
+
+ if (strcmp(item->key, item_key) == 0)
+ return item;
+
+ return NULL;
+}
+
+/*
+ * Find the first item with a key matching item_key, if any exists.
+ */
+static inline struct menu_item *menu_item_by_key(struct menu *m,
+ char *item_key)
+{
+ return menu_items_iter(m, menu_item_key_match, item_key);
+}
+
+/*
+ * Checks whether or not the default menu item should be used without
+ * prompting for a user choice. If the menu is set to always prompt, return
+ * 0. Otherwise, return 1 to indicate we should use the default menu item.
+ */
+static inline int menu_use_default(struct menu *m)
+{
+ return !m->prompt;
+}
+
+/*
+ * Set *choice to point to the default item's data, if any default item was
+ * set, and returns 1. If no default item was set, returns -ENOENT.
+ */
+static inline int menu_default_choice(struct menu *m, void **choice)
+{
+ if (m->default_item) {
+ *choice = m->default_item->data;
+ return 1;
+ }
+
+ return -ENOENT;
+}
+
+/*
+ * Displays the menu and asks the user to choose an item. *choice will point
+ * to the private data of the item the user chooses. The user makes a choice
+ * by inputting a string matching the key of an item. Invalid choices will
+ * cause the user to be prompted again, repeatedly, until the user makes a
+ * valid choice. The user can exit the menu without making a choice via ^c.
+ *
+ * Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
+ */
+static inline int menu_interactive_choice(struct menu *m, void **choice)
+{
+ char cbuf[CONFIG_SYS_CBSIZE];
+ struct menu_item *choice_item = NULL;
+ int readret;
+
+ while (!choice_item) {
+ cbuf[0] = '\0';
+
+ menu_display(m);
+
+ readret = readline_into_buffer("Enter choice: ", cbuf);
+
+ if (readret >= 0) {
+ choice_item = menu_item_by_key(m, cbuf);
+
+ if (!choice_item)
+ printf("%s not found\n", cbuf);
+ } else {
+ printf("^C\n");
+ return -EINTR;
+ }
+ }
+
+ *choice = choice_item->data;
+
+ return 1;
+}
+
+/*
+ * menu_default_set() - Sets the default choice for the menu. This is safe to
+ * call more than once on a menu.
+ *
+ * m - Points to a menu created by menu_create().
+ *
+ * item_key - Points to a string that, when compared using strcmp, matches the
+ * key for an existing item in the menu.
+ *
+ * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
+ * key matching item_key is found.
+ */
+int menu_default_set(struct menu *m, char *item_key)
+{
+ struct menu_item *item;
+
+ if (!m)
+ return -EINVAL;
+
+ item = menu_item_by_key(m, item_key);
+
+ if (!item)
+ return -ENOENT;
+
+ m->default_item = item;
+
+ return 1;
+}
+
+/*
+ * menu_get_choice() - Returns the user's selected menu entry, or the default
+ * if the menu is set to not prompt. This is safe to call more than once.
+ *
+ * m - Points to a menu created by menu_create().
+ *
+ * choice - Points to a location that will store a pointer to the selected
+ * menu item. If no item is selected or there is an error, no value will be
+ * written at the location it points to.
+ *
+ * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
+ * default has been set and the menu is set to not prompt, or -EINTR if the
+ * user exits the menu via ^c.
+ */
+int menu_get_choice(struct menu *m, void **choice)
+{
+ if (!m || !choice)
+ return -EINVAL;
+
+ if (menu_use_default(m))
+ return menu_default_choice(m, choice);
+
+ return menu_interactive_choice(m, choice);
+}
+
+/*
+ * menu_item_add() - Adds or replaces a menu item. Note that this replaces the
+ * data of an item if it already exists, but doesn't change the order of the
+ * item.
+ *
+ * m - Points to a menu created by menu_create().
+ *
+ * item_key - Points to a string that will uniquely identify the item. The
+ * string will be copied to internal storage, and is safe to discard after
+ * passing to menu_item_add.
+ *
+ * item_data - An opaque pointer associated with an item. It is never
+ * dereferenced internally, but will be passed to the item_data_print, and
+ * will be returned from menu_get_choice if the menu item is selected.
+ *
+ * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
+ * insufficient memory to add the menu item.
+ */
+int menu_item_add(struct menu *m, char *item_key, void *item_data)
+{
+ struct menu_item *item;
+
+ if (!m)
+ return -EINVAL;
+
+ item = menu_item_by_key(m, item_key);
+
+ if (item) {
+ item->data = item_data;
+ return 1;
+ }
+
+ item = malloc(sizeof *item);
+ if (!item)
+ return -ENOMEM;
+
+ item->key = strdup(item_key);
+
+ if (!item->key) {
+ free(item);
+ return -ENOMEM;
+ }
+
+ item->data = item_data;
+
+ list_add_tail(&item->list, &m->items);
+
+ return 1;
+}
+
+/*
+ * menu_create() - Creates a menu handle with default settings
+ *
+ * title - If not NULL, points to a string that will be displayed before the
+ * list of menu items. It will be copied to internal storage, and is safe to
+ * discard after passing to menu_create().
+ *
+ * prompt - If 0, don't ask for user input.
+ *
+ * item_data_print - If not NULL, will be called for each item when the menu
+ * is displayed, with the pointer to the item's data passed as the argument.
+ * If NULL, each item's key will be printed instead. Since an item's key is
+ * what must be entered to select an item, the item_data_print function should
+ * make it obvious what the key for each entry is.
+ *
+ * Returns a pointer to the menu if successful, or NULL if there is
+ * insufficient memory available to create the menu.
+ */
+struct menu *menu_create(char *title, int prompt,
+ void (*item_data_print)(void *))
+{
+ struct menu *m;
+
+ m = malloc(sizeof *m);
+
+ if (!m)
+ return NULL;
+
+ m->default_item = NULL;
+ m->prompt = prompt;
+ m->item_data_print = item_data_print;
+
+ if (title) {
+ m->title = strdup(title);
+ if (!m->title) {
+ free(m);
+ return NULL;
+ }
+ } else
+ m->title = NULL;
+
+
+ INIT_LIST_HEAD(&m->items);
+
+ return m;
+}
+
+/*
+ * menu_destroy() - frees the memory used by a menu and its items.
+ *
+ * m - Points to a menu created by menu_create().
+ *
+ * Returns 1 if successful, or -EINVAL if m is NULL.
+ */
+int menu_destroy(struct menu *m)
+{
+ if (!m)
+ return -EINVAL;
+
+ menu_items_iter(m, menu_item_destroy, NULL);
+
+ if (m->title)
+ free(m->title);
+
+ free(m);
+
+ return 1;
+}
diff --git a/doc/README.menu b/doc/README.menu
new file mode 100644
index 0000000..f55eb80
--- /dev/null
+++ b/doc/README.menu
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2010-2011 Calxeda, 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; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+U-boot provides a set of interfaces for creating and using simple, text
+based menus. Menus are displayed as lists of labeled entries on the
+console, and an entry can be selected by entering its label.
+
+To use the menu code, enable CONFIG_MENU, and include "menu.h" where
+the interfaces should be available.
+
+Menus are composed of items. Each item has a key used to identify it in
+the menu, and an opaque pointer to data controlled by the consumer.
+
+Interfaces
+----------
+#include "menu.h"
+
+/*
+ * Consumers of the menu interfaces will use a struct menu * as the
+ * handle for a menu. struct menu is only fully defined in menu.c,
+ * preventing consumers of the menu interfaces from accessing its
+ * contents directly.
+ */
+struct menu;
+
+/*
+ * NOTE: See comments in common/menu.c for more detailed documentation on
+ * these interfaces.
+ */
+
+/*
+ * menu_create() - Creates a menu handle with default settings
+ */
+struct menu *menu_create(char *title, int prompt,
+ void (*item_data_print)(void *));
+
+/*
+ * menu_item_add() - Adds or replaces a menu item
+ */
+int menu_item_add(struct menu *m, char *item_key, void *item_data);
+
+/*
+ * menu_default_set() - Sets the default choice for the menu
+ */
+int menu_default_set(struct menu *m, char *item_key);
+
+/*
+ * menu_get_choice() - Returns the user's selected menu entry, or the
+ * default if the menu is set to not prompt.
+ */
+int menu_get_choice(struct menu *m, void **choice);
+
+/*
+ * menu_destroy() - frees the memory used by a menu and its items.
+ */
+int menu_destroy(struct menu *m);
+
+
+Example Code
+------------
+This example creates a menu that always prompts, and allows the user
+to pick from a list of tools. The item key and data are the same.
+
+#include "menu.h"
+
+char *tools[] = {
+ "Hammer",
+ "Screwdriver",
+ "Nail gun",
+ NULL
+};
+
+char *pick_a_tool(void)
+{
+ struct menu *m;
+ int i;
+ char *tool = NULL;
+
+ m = menu_create("Tools", 1, NULL);
+
+ for(i = 0; tools[i]; i++) {
+ if (menu_item_add(m, tools[i], tools[i]) != 1) {
+ printf("failed to add item!");
+ menu_destroy(m);
+ return NULL;
+ }
+ }
+
+ if (menu_get_choice(m, (void **)&tool) != 1)
+ printf("Problem picking tool!\n");
+
+ menu_destroy(m);
+
+ return tool;
+}
+
+void caller(void)
+{
+ char *tool = pick_a_tool();
+
+ if (tool) {
+ printf("picked a tool: %s\n", tool);
+ use_tool(tool);
+ }
+}
diff --git a/include/menu.h b/include/menu.h
new file mode 100644
index 0000000..d47e1a0
--- /dev/null
+++ b/include/menu.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2010-2011 Calxeda, 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; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __MENU_H__
+#define __MENU_H__
+
+struct menu;
+
+struct menu *menu_create(char *title, int prompt,
+ void (*item_data_print)(void *));
+int menu_default_set(struct menu *m, char *item_key);
+int menu_get_choice(struct menu *m, void **choice);
+int menu_item_add(struct menu *m, char *item_key, void *item_data);
+int menu_destroy(struct menu *m);
+
+#endif /* __MENU_H__ */
--
1.7.0.4
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