New command bootmenu: ANSI terminal boot menu support

The "bootmenu" command uses U-Boot menu interfaces and provides
a simple mechanism for creating menus with several boot items.
When running this command the menu will be assembled as defined
by a set of environment variables which contain a title and
command key-value pairs. The "Up" and "Down" keys are used for
navigation through the items. Current active menu item is
highlighted and can be selected using the "Enter" key.

The command interprets and generates various ANSI escape
sequencies, so for proper menu rendering and item selection
the used terminal should support them.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
[agust: various fixes and documentation updates]
Signed-off-by: Anatolij Gustschin <agust@denx.de>

1 files changed, 115 insertions, 0 deletions

diff --git a/doc/README.bootmenu b/doc/README.bootmenu
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+/*
+ * (C) Copyright 2011-2012 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * 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
+ */
+
+ANSI terminal bootmenu command
+
+The "bootmenu" command uses U-Boot menu interfaces and provides
+a simple mechanism for creating menus with different boot items.
+The cursor keys "Up" and "Down" are used for navigation through
+the items. Current active menu item is highlighted and can be
+selected using the "Enter" key. The selection of the highlighted
+menu entry invokes an U-Boot command (or a list of commands)
+associated with this menu entry.
+
+The "bootmenu" command interprets ANSI escape sequencies, so
+an ANSI terminal is required for proper menu rendering and item
+selection.
+
+The assembling of the menu is done via a set of environment variables
+"bootmenu_<num>" and "bootmenu_delay", i.e.:
+
+  bootmenu_delay=<delay>
+  bootmenu_<num>="<title>=<commands>"
+
+  <delay> is the autoboot delay in seconds, after which the first
+  menu entry will be selected automatically
+
+  <num> is the boot menu entry number, starting from zero
+
+  <title> is the text of the menu entry shown on the console
+  or on the boot screen
+
+  <commands> are commands which will be executed when a menu
+  entry is selected
+
+  (title and commands are separated by first appearance of '='
+   character in the environment variable)
+
+First (optional) argument of the "bootmenu" command is a delay specifier
+and it overrides the delay value defined by "bootmenu_delay" environment
+variable. If the environment variable "bootmenu_delay" is not set or if
+the argument of the "bootmenu" command is not specified, the default delay
+will be CONFIG_BOOTDELAY. If delay is 0, no menu entries will be shown on
+the console (or on the screen) and the command of the first menu entry will
+be called immediately. If delay is less then 0, bootmenu will be shown and
+autoboot will be disabled.
+
+Bootmenu always adds menu entry "U-Boot console" at the end of all menu
+entries specified by environment variables. When selecting this entry
+the bootmenu terminates and the usual U-Boot command prompt is presented
+to the user.
+
+Example environment:
+
+  setenv bootmenu_0 Boot 1. kernel=bootm 0x82000000  # Set first menu entry
+  setenv bootmenu_1 Boot 2. kernel=bootm 0x83000000  # Set second menu entry
+  setenv bootmenu_2 Reset board=reset                # Set third menu entry
+  setenv bootmenu_3 U-Boot boot order=boot           # Set fourth menu entry
+  bootmenu 20        # Run bootmenu with autoboot delay 20s
+
+
+The above example will be rendered as below
+(without decorating rectangle):
+
+┌──────────────────────────────────────────┐
+│                                          │
+│  *** U-Boot Boot Menu ***                │
+│                                          │
+│     Boot 1. kernel                       │
+│     Boot 2. kernel                       │
+│     Reset board                          │
+│     U-Boot boot order                    │
+│     U-Boot console                       │
+│                                          │
+│  Hit any key to stop autoboot: 20        │
+│  Press UP/DOWN to move, ENTER to select  │
+│                                          │
+└──────────────────────────────────────────┘
+
+Selected menu entry will be highlighted - it will have inverted
+background and text colors.
+
+To enable the "bootmenu" command add following definitions to the
+board config file:
+
+  #define CONFIG_CMD_BOOTMENU
+  #define CONFIG_MENU
+
+To run the bootmenu at startup add these additional definitions:
+
+  #define CONFIG_AUTOBOOT_KEYED
+  #define CONFIG_BOOTDELAY 30
+  #define CONFIG_MENU_SHOW
+
+When you intend to use the bootmenu on color frame buffer console,
+make sure to additionally define CONFIG_CFB_CONSOLE_ANSI in the
+board config file.