Become superuser or assume an equivalent role.
Roles contain authorizations and privileged commands. For more information about roles, see Configuring RBAC (Task Map) in System Administration Guide: Security Services.
To set the default boot entry in the active GRUB menu, type:
# bootadm set-menu menu-entry
Maintains the GRUB menu. The location of the active GRUB menu is boot/grub/menu.lst. Applies to x86 bases systems only.
Specifies the GRUB menu entry to set as the default.
To verify default menu entry has been changed, type:
# bootadm list-menu
The new default menu entry should be displayed.
This example shows how to switch the default GRUB menu to one of the menu entries that is displayed in the previous example. The menu entry that is selected is The Linux, menu entry 2.
# bootadm set-menu default=2
For a description of the menu.lst file in each GRUB implementation, see x86: Supported GRUB Versions.