From f74556693bca2ff61e3e0c103f90e1d552d795b6 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 22 Feb 2013 11:51:06 +0100 Subject: [PATCH] x86: honor ACPI indicating absence of CMOS RTC On such systems we can boot through EFI only. Signed-off-by: Jan Beulich Acked-by: Keir Fraser --- xen/arch/x86/time.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index 244b43e7f0..56bffdbe39 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -754,6 +754,9 @@ static unsigned long get_cmos_time(void) return res; } + if ( unlikely(acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC) ) + panic("System without CMOS RTC must be booted from EFI\n"); + spin_lock_irqsave(&rtc_lock, flags); /* read RTC exactly on falling edge of update flag */ -- 2.30.2