doc: move README.bootmenu to HTML doc

Convert README.bootmenu to reStructured text and move it to
usage/bootmenu.rst.

Adjust the text concerning configuration settings as these now are managed
via Kconfig.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Pali Rohár <pali@kernel.org>
diff --git a/doc/README.bootmenu b/doc/README.bootmenu
deleted file mode 100644
index 9ff89f2..0000000
--- a/doc/README.bootmenu
+++ /dev/null
@@ -1,98 +0,0 @@
-SPDX-License-Identifier: GPL-2.0+
-/*
- * (C) Copyright 2011-2012 Pali Rohár <pali@kernel.org>
- */
-
-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_AUTOBOOT_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.
diff --git a/doc/usage/bootmenu.rst b/doc/usage/bootmenu.rst
new file mode 100644
index 0000000..1f094ad
--- /dev/null
+++ b/doc/usage/bootmenu.rst
@@ -0,0 +1,95 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. (C) Copyright 2011-2012 Pali Rohár <pali@kernel.org>
+
+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 the first appearance of a '='
+character in the value of the environment variable.
+
+The 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::
+
+    *** 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
+
+The selected menu entry will be highlighted - it will have inverted
+background and text colors.
+
+The "bootmenu" cammand is enabled by::
+
+    CONFIG_CMD_BOOTMENU=y
+
+To run the bootmenu at startup add these additional settings::
+
+    CONFIG_AUTOBOOT_KEYED=y
+    CONFIG_BOOTDELAY=30
+    CONFIG_AUTOBOOT_MENU_SHOW=y
+
+When you intend to use the bootmenu on a color frame buffer console,
+make sure to additionally define::
+
+    CONFIG_CFB_CONSOLE_ANSI=y
diff --git a/doc/usage/index.rst b/doc/usage/index.rst
index 063e970..d0f5a9f 100644
--- a/doc/usage/index.rst
+++ b/doc/usage/index.rst
@@ -11,4 +11,5 @@
 .. toctree::
    :maxdepth: 1
 
+   bootmenu
    pstore