The first menu item (usually item 0) in the Main menu allows you to set a default menu item in the Main menu that will be automatically selected when E2B boots.
You can also set a timeout in seconds, so that it will auto-run.
This menu entry is determined by the standard E2B file \_ISO\MAINMENU\$$$SetDefaultMenu.mnu which is usually always enumerated first by E2B, and so appears as the first menu item 0.
Auto-run any payload file
If you have a payload file that is in another menu folder, then you can create a .mnu file for it and place the .mnu file in the \_ISO\MAINMENU folder.
e.g. If you have \_ISO\LINUX\Ubuntu.iso which you want to automatically run, create a .mnu file. I suggest using a name that begins with $$ so that it's menu number does not change if you add more payload files - this way it will always be menu item 1 ($$$SetDefaultMenu.mnu is menu item 0):
title Ubuntu\n For default selection
If you want the menu entry in the Main menu to be 'invisible' (so that there will be a blank line in the menu), do not specify any text for the title and do not add the 'boot' line...
title \n Ubuntu.iso will auto-boot
For other .mnu examples, such as for a Windows Installer ISO, see the \_ISO\docs\Sample mnu Files folder.
Note: If using a Virtual Machine, setting a Main menu default will not work unless the VM has full write access to the USB drive. Using RMPrepUSB+QEMU (F11) or VBox+VMUB will work. Using VMWare+Plop or QEMU_MENU_TEST (run as admin).cmd, etc. will not work correctly.
Remove the 'Set default menu entry and timeout' menu item
To prevent the user from using the ' set default' menu, it can be removed from the Main menu using a setting in the \_ISO\MyE2B.cfg file:
You can preset the default menu entry and timeout values (instructions are also in the Sample_MyE2B.cfg file):
Create a new \_ISO\menu_defaults.txt file (this example sets the 2nd menu item as the default with a 10 second timeout)
# set the default entry and timeout (debug 0 prevents menu item number at top right from being displayed)
Suppress the countdown message
You can remove the user countdown timeout message (see screenshot below) shown by grub4dos if you use the 'patchme' grub4dos batch file included with E2B. This patches the grub4dos code on the USB drive.
See \_ISO\docs\PatchMe_ReadMe.txt for instructions.
Setting defaults for sub-menus
It is possible to make a small .mnu file which selects a default sub-menu entry for each sub-menu.
In this way you can configure E2B to automatically boot to any menu entry in any sub-menu.
You can set a timeout for each sub-menu too. This trick uses a .mnu file which MUST be enumerated first in each sub-folder and therefore should have a name which is enumerated first, such as $$$$Default.mnu.
For example, suppose you want the LINUX sub-menu to always select the 4th menu item when the LINUX sub-menu is loaded, and you want the WINPE sub-menu to select the 2nd item with a timeout of 10 seconds when it is selected:
If you set the Main menu default to run the WINPE sub-menu entry with a timeout (e.g. 3 seconds), then E2B will boot first to the Main menu and then to the WINPE sub-menu and then run the 2nd entry in that menu after 10 seconds. Note however, that if you add any more payload files, it could affect the menu numbering!