Greetings, if the init is what I think it is ( setting bit 5 in RTC index 0x0a, the divider), it should be the same for all RTC. The part that tends to differ is the PnP stuff. The index accesses from port 0x70-71 tend to stick to standards.
G'day, sjames On 10 Dec 2002, Eric W. Biederman wrote: > Kevin Hester <[EMAIL PROTECTED]> writes: > > > Hi all, > > > > First I'd like to describe a problem I've encountered: > > > > I have a virgin motherboard that has never been powered up before. i.e. this > > board was not manufactured elsewhere and a 'standard' BIOS has never been > > used on it. > > > > When booting this board I discovered an interesting problem: the boot would > > hang when the "hwclock" tool was invoked by /etc/rcS.d/<some script that > > reads the rtc>. > > > > The underlying problem is that this common linux utility is reading the RTC > > via the standard IO ports 70-71. Within this RTC window all of the dallas > > semiconductor RTC clones use a few bits in register 0x0a to enable the clock > > when power is down. The default values of these bits do not enable the clock > > - presumably to avoid draining the battery until the boards are first placed > > into production. > > > > I've modified my version of linuxbios to ensure that these bits are set to > > enable the RTC updates. My question is, where is the best place to make this > > change? > > Assuming your RTC hardware is in your southbridge: > src/southbridge/<manufacturer>/<chipset>/rtc.c or something like that. > > It is my experience that only for reading the real time clock is > a real time clock a real time clock. The control functions which are > handled rarely tend to be specific to an individual implementation. Though > there are generally similarities within a family of implementations. > > > 1) In some non linuxbios component (i.e. some little app run at boot time) > > > > 2) In linuxbios, but restricted to my mainboard. > > > > 3) In linuxbios, but in 'common' code that applies to all intel boards. > > In linuxbios common code that applies to your southbridge. > For now it will probably work best to have that code called from your mainboard, > and others who need it can call that code as well.\ > > > I'm in favor of option 3, but I thought I'd ask first. I think this problem > > would apply to any board. The reason we haven't seen it before is that most > > folks are running linux bios on boards that once had a standard bios. The > > standard bios has already 'activated' the RTC updates. > > I suspect being the second BIOS on the boards has certainly had something to > do with it. But given how much chips vary this may simply be an oddity of > your particular variation of the board. > > > What do you think? > > Until I see proof that this feature was in the original motorola mc146818 > real time clock, and has been in all implementations there after, I > don't want the code to apply all boards indescrimanently. > > Eric > > _______________________________________________ > Linuxbios mailing list > [EMAIL PROTECTED] > http://www.clustermatic.org/mailman/listinfo/linuxbios > -- -------------------------steven james, director of research, linux labs ... ........ ..... .... 230 peachtree st nw ste 701 the original linux labs atlanta.ga.us 30303 -since 1995 http://www.linuxlabs.com office 404.577.7747 fax 404.577.7743 ----------------------------------------------------------------------- _______________________________________________ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
