Noun
English Wikipedia has an article on:bootupWikipedia
bootup (plural bootups)
(computing) The process of booting up.
During early bootup, the RAID is implemented by the firmware and, once the operating system has been more completely loaded, the drivers take over control. Source: Internet
The Model 4 is also capable of running all Model III software when a Model III operating system disk is detected and loaded during bootup, with a 64×16 video mode and Model III ROMs mapped from address zero. Source: Internet