readme

Windows上的精简Linux系统

          Text User Interface using comboot
          ---------------------------------

This is a menu system written by Murali Krishnan Ganapathy and ported
from OpenWatcom to gcc by HPA.

To configure the menus, you need to set up a menu configuration file
to have the menu items you desire, then build the menu system using
make.  You can use either simple.c or complex.c as a starting point
for your own menu configuration file; then add the name with a .com
extension to the MENUS list in the Makefile.

The resulting code runs both under DOS as well as SYSLINUX. A trivial
memory allocation routine is implemented, to reduce the memory footprint 
of this utility.

Menu Features currently supported are:
* menu items, 
* submenus, 
* disabled items,
* checkboxes,
* invisible items (useful for dynamic menus), and
* Radio menus

The keys used are:

* Arrow Keys, PgUp, PgDn, Home, End Keys
* Space to switch state of a checkbox
* Enter to choose the item
* Escape to exit from it
* Shortcut keys

Features
--------
This is a general purpose menu system implemented using only BIOS calls, 
so it can be executed in a COMBOOT environment as well. It is highly
customizable. Some features include:

* Status line
    Display any help information associated with each menu item.
* Window
    Specify a window within which the menu system draws all its menu's.
    It is upto the user to ensure that the menu's fit within the window.
* Positioning submenus
    By default, each submenu is positioned just below the corresponding 
    entry of the parent menu. However, the user may position each menu
    at a specific location of his choice. This is useful, when the menu's
    have lots of options.
* Registering handlers for each menu item 
    This is mainly used for checkboxes and radiomenu's, where a selection may
    result in disabling other menu items/checkboxes 
* Global Handler
    This is called every time the menu is redrawn. The user can display
    additional information (usually outside the window where the menu is 
    being displayed). See the complex.c for an example, where the global
    handler is used to display the choices made so far.
* Shortcut Keys
    With each item one can register a shortcut key from [A-Za-z0-9]. 
    Pressing a key within that range, will take you to the next item
    with that shortcut key (so you can have multiple items with the
    same shortcut key). The default shortcut key for each item, is 
    the lower case version of the first char of the item in the range 
    [A-Za-z0-9].
* Escape Keys
    Each item entry can have a substring enclosed in < and >. This part
    is highlighted. Can be used to highlight the shortcut keys. By default
    if an item has a <, then the first char inside < and > in the range
    [A-Za-z0-9] is converted to lower case and set as the shortcut key.
* Ontimeout handler
    The user can register an ontimeout handler, which gets called if 
    no key has been pressed for a user specific amount of time (default 5 min).
    For an example see the complex.c file.

Credits
-------
* The Watcom developers and Peter Anvin for figuring out an OS 
  independent startup code.

- Murali ([e-mail])