enhanced RTC and SMP on PowerMac

enhanced RTC and SMP on PowerMac

[Naoki Takebayashi]

Is enhanced RTC supposed to work on PowerMac?  When I compile with
CONFIG_RTC, the kernel doesn't boot up and dies when it hits the following
line:

   /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
   CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);

in the function, __initfunc(int rtc_init(void)), in
linux/drivers/char/rtc.c.

I'm using 2.2.14 on PowerSurge board (UMAX S900).

I was looking at the linux/arch/ppc/kernel/pmac_time.c and prep_time.c.
And I noticed, that PReP machine uses CMOS_WRITE to access RTC, but
PowerMac uses cuda to access RTC instead of CMOS_WRITE.  So I'm guessing
that enhanced RTC doesn't work on the PowerMacs, right now.


Naoki Takebayashi     <ntakebay@bio.indiana.edu>
--- Dept. of Biology, Indiana University, Jordan Hall 142
--- 1001 E. Third St. Bloomington, IN 47405-3700 USA


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Re: enhanced RTC and SMP on PowerMac

[Joseph Garcia]

Naoki Takebayashi wrote:
> 
> Is enhanced RTC supposed to work on PowerMac?  When I compile with
> CONFIG_RTC, the kernel doesn't boot up and dies when it hits the following
> line:
> 
>    /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
>    CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);

I have the same problem.  I dont think it should work.  (CMOS on a ppc?)

I have noticed that the 'clock' program seems to access the rtc.  Assuming it
is, it may have the code we want to put in the kernel.

-- 
Joseph P. Garcia      jpgarcia@execpc.com      jpgarcia@lidar.ssec.wisc.edu
CS Undergraduate                      Student Employee - Systems Programmer
University of Wisconsin - Madison                            UW Lidar Group

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Re: enhanced RTC and SMP on PowerMac

[Charles E. Leiserson, Jr.]

> > Is enhanced RTC supposed to work on PowerMac?  When I compile with
> > CONFIG_RTC, the kernel doesn't boot up and dies when it hits the following
> > line:
> > 
> >    /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
> >    CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);
> 
> I have the same problem.  I dont think it should work.  (CMOS on a ppc?)
> 
> I have noticed that the 'clock' program seems to access the rtc.  Assuming it
> is, it may have the code we want to put in the kernel.

Don't use the RTC option.  That's only for x86.  Also, SMP appears to be broken on 2.2.14.


					- Ricky


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Re: enhanced RTC and SMP on PowerMac

[Geert Uytterhoeven]

On Wed, 5 Jan 2000, Naoki Takebayashi wrote:
> Is enhanced RTC supposed to work on PowerMac?  When I compile with
> CONFIG_RTC, the kernel doesn't boot up and dies when it hits the following
> line:
> 
>    /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
>    CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);
> 
> in the function, __initfunc(int rtc_init(void)), in
> linux/drivers/char/rtc.c.
> 
> I'm using 2.2.14 on PowerSurge board (UMAX S900).
> 
> I was looking at the linux/arch/ppc/kernel/pmac_time.c and prep_time.c.
> And I noticed, that PReP machine uses CMOS_WRITE to access RTC, but
> PowerMac uses cuda to access RTC instead of CMOS_WRITE.  So I'm guessing
> that enhanced RTC doesn't work on the PowerMacs, right now.

To use enhanced RTC (/dev/rtc) on anything without a PC RTC, you have to write
a specific driver for your hardware first.

Gr{oetje,eeting}s,
--
Geert Uytterhoeven -- Linux/{m68k~Amiga,PPC~CHRP} -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds


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