1.. _rtc-virt-hld: 2 3RTC Virtualization 4################## 5 6This document describes the real-time clock (RTC) virtualization implementation 7in the ACRN Device Model. 8 9vRTC is a read-only RTC for the pre-launched VM, Service VM, and post-launched 10RTVM. It supports read/write (RW) for the CMOS address port 0x70 and read only 11(RO) for the CMOS data port 0x71. Reads to the CMOS RAM offsets are fetched from 12the CMOS hardware directly. Writes to the CMOS offsets are discarded. 13