[SeaBIOS] [PATCH]: enable USE_PLATFORM_CLOCK bit in FADT flags

Marcelo Tosatti mtosatti at redhat.com
Fri Jul 20 12:24:27 CEST 2012


On Fri, Jul 20, 2012 at 07:49:03AM +0300, Gleb Natapov wrote:
> On Thu, Jul 19, 2012 at 08:44:07PM -0400, Kevin O'Connor wrote:
> > On Tue, Jul 17, 2012 at 02:18:00PM -0300, Marcelo Tosatti wrote:
> > > 
> > > Enable bit 15 (USE_PLATFORM_CLOCK) of FADT flags field so that
> > > older Windows guests do not make use of the TSC for timestamping. 
> > 
> > I fixed up and committed this patch.  But after I committed it, I
> > realized it reverted Gleb's "Drop FIX_RTC flag from FADT" patch
> > (c7be281b).  Gleb, if you can you confirm c7be281b is still valid I'll
> > put it back in.
> > 
> It also reverts 20fcf9b.

20fcf9b = addition of RTC_S4 (bit 7). 

The patch i sent to add bit 15 does not touch that:

-    /* WBINVD + PROC_C1 + SLP_BUTTON + RTC_S4 */
-    fadt->flags = cpu_to_le32((1 << 0) | (1 << 2) | (1 << 5) | (1 << 7));
+    /* WBINVD + PROC_C1 + SLP_BUTTON + RTC_S4 + USE_PLATFORM_CLOCK */
+    fadt->flags = cpu_to_le32((1 << 0) | (1 << 2) | (1 << 5) | (1 << 7) |
+                              (1 << 15));

> They are both still valid. Marcelo what source
> tree the patch was against?

commit 12c991e1da182a0e6e2028f130ded512102c8842
Author: Ian Campbell <ian.campbell at citrix.com>
Date:   Thu Jun 28 11:08:33 2012 +0100




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