Subject: Re: proposal for changes to todr interface
To: Izumi Tsutsui <>
From: David Laight <>
List: tech-kern
Date: 09/06/2006 19:40:14
On Thu, Sep 07, 2006 at 02:13:40AM +0900, Izumi Tsutsui wrote:
> > Does the i8254 used e.g. in PCs have a DST flag? That should be
> > supported by the common infrastructure.
> Note i8254 is a interval timer chip, not a todclock chip.
> As you can see x86/isa/clock.c, tod is stored in mc146818
> compatible.

The register set for the RTC chip used in PCs does have a 'DST' flag.
Unfortunately windows (was win98 I was playing with) doesn't change
it when it 'warps' the system time at the start/end of summertime.
Neither do the BIOS clock setting functions include it.


David Laight: