How can the command used by SystemRescueCD to find and boot existing operating systems be executed manually?

SystemRescueCD has the option to locate existing operating systems on a system and give you the option to boot one of your choice. It lists them in the boot options as findroot. Is there a command to do the same after it boots to the command line? The system I used takes too long time to boot SystemRescueCD choice menu and by the time I get to the screen the regular prompt is showing. Can the command which locates the existing OS and presents the menu on which one to boot be run from the command line?