vPIT is used as a source of system timer by UEFI (e.g. OVMF).
This is ported from Bhyve, with a few changes:
- move to user space, using POSIX timer
- support timer mode 3
- improve the emulation of OUT and STATUS byte
- improve the emulation of counter behavior
- improve the emulation of CE update in periodic mode
- treat CR == 0 as 0x10000
Origin: FreeBSD
License: BSD-3-Clause
URL: https://svnweb.freebsd.org/
commit: 283291
Purpose: Adding vPIT support.
Maintained-by: External
Tracked-On: #1392
Signed-off-by: Peter Fang <peter.fang@intel.com>
Acked-by: Yin Fengwei <fengwei.yin@intel.com>
Some firmware (e.g. UEFI) uses RTC CMOS to fetch the system's memory
configuration. Put lowmem / highmem info in the designated area.
This is a port of Bhyve vRTC's user-space logic.
v1 -> v2:
* move KB/MB/GB to macros.h
* move nvram offset definitions to rtc.h
Tracked-On: #1390
Signed-off-by: Peter Fang <peter.fang@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
Peter Fang