jˈuːfi pɹəvˈaɪdz bˈækwɚd kəmpˌæɾəbˈɪlᵻɾi wɪð lˈɛɡəsi sˈɪstəmz baɪ ɹɪzˈɜːvɪŋ ðə fˈɜːst blˈɑːk sˈɛktɚ ʌvðə pɑːɹtˈɪʃən fɔːɹ kəmpˌæɾəbˈɪlᵻɾi kˈoʊd, ɪfˈɛktɪvli kɹiːˈeɪɾɪŋ ɐ lˈɛɡəsi bˈuːt sˈɛktɚ.
UEFI provides backward compatibility with legacy systems by reserving the first block (sector) of the partition for compatibility code, effectively creating a legacy boot sector.