[coreboot] libpayload: add gettimeofday()

[Jordan Crouse]

Changes made - awaiting your ACK.

On 21/04/08 21:02 +0200, Uwe Hermann wrote:
> On Wed, Apr 16, 2008 at 05:44:45PM -0600, Jordan Crouse wrote:
> > libpayload:  Add gettimeofday() and friends
> > 
> > Add a gettimeofday() implementation - it works pretty well, but it
> > drifts a little bit so its not very suitable for keeping time.  It
> > works best to track changes in time over small periods of time.
> > 
> > Signed-off-by: Jordan Crouse <jordan.crouse at amd.com>
> > Index: libpayload/drivers/nvram.c
> > ===================================================================
> > --- libpayload.orig/drivers/nvram.c	2008-04-18 04:16:35.000000000 -0600
> > +++ libpayload/drivers/nvram.c	2008-04-18 04:20:20.000000000 -0600
> > @@ -93,3 +93,42 @@
> >  	outb(addr, rtc_port);
> >  	outb(val, rtc_port + 1);
> >  }
> > +
> > +/**
> > + * Return 1 if the NVRAM is currently updating
> > + */
> 
> ... "and zero otherwise."
> 
> Also, please add a "@return" item for doxygen.
> 
> 
> > +int nvram_updating(void)
> > +{
> > +       return (nvram_read(NVRAM_RTC_FREQ_SELECT) & NVRAM_RTC_UIP) ? 1 : 0;
> > +}
> > +
> > +/**
> > + * Get the current time and date from the RTC
> > + *
> > + * @param time A pointer to a broken-down time structure
> > + */
> > +void rtc_read_clock(struct tm *time)
> > +{
> > +	memset(time, 0, sizeof(*time));
> > +
> > +	while(nvram_updating());
> > +
> > +	time->tm_mon = bcd2dec(nvram_read(NVRAM_RTC_MONTH)) - 1;
> > +	time->tm_sec = bcd2dec(nvram_read(NVRAM_RTC_SECONDS));
> > +	time->tm_min = bcd2dec(nvram_read(NVRAM_RTC_MINUTES));
> > +	time->tm_mday = bcd2dec(nvram_read(NVRAM_RTC_DAY));
> > +	time->tm_hour = bcd2dec(nvram_read(NVRAM_RTC_HOURS));
> > +
> > +	/* Instead of finding the century register,
> > +	   we just make an assumption that if the year value is
> > +	   less then 80, then it is 2000+
> > +	*/
> 
> I'd add a FIXME or TODO here :)
> 
> 
> > +
> > +	time->tm_year = bcd2dec(nvram_read(NVRAM_RTC_YEAR));
> > +
> > +	if (time->tm_year < 80)
> > +		time->tm_year += 100;
> > +}
> > +
> > +
> > Index: libpayload/include/arch/rdtsc.h
> > ===================================================================
> > --- libpayload.orig/include/arch/rdtsc.h	2008-04-18 04:16:34.000000000 -0600
> > +++ libpayload/include/arch/rdtsc.h	2008-04-18 04:17:09.000000000 -0600
> > @@ -30,9 +30,9 @@
> >  #ifndef _ARCH_RDTSC_H
> >  #define _ARCH_RDTSC_H
> >  
> > -static inline unsigned long long rdtsc(void)
> > +static inline u64 rdtsc(void)
> >  {
> > -	unsigned long long val;
> > +	u64 val;
> 
> Yep.
> 
> Can the inline be removed as well or is it required here?
> 
> 
> > +static unsigned int day_of_year(int mon, int day, int year)
> > +{
> > +	static u8 mdays[12] = { 31, 28, 31, 30, 31, 30,
> > +				31, 31, 30, 31, 30, 31 };
> > +
> > +	int ret = 0, i;
> 
> Maybe this?
> 
> 	int i, ret = 0;
> 
> Looks a bit less confusing. Or only "int ret, i" and put the
> "ret = 0" in the for-loop:
> 
> 	for(i = 0, ret = 0; i < mon; i++)
> 
> 
> > +
> > +	f(r(i = 0; i < mon; i++) {
> > +		ret += mdays[i];
> > +		
> > +		if (i == 1 && (year % 4))
> > +			ret++;
> > +	}
> > +	
> > +	return (ret + day);
> > +}
> > +
> > +static void gtod_init(void)
> 
> Nonovious abbreviation, use gettimeofday_init() for better readability
> please. Ditto for other "gtod" occurences.
> 
> A test on real hardware is pending, I'll report back.
> 
> 
> Uwe.
> -- 
> http://www.hermann-uwe.de  | http://www.holsham-traders.de
> http://www.crazy-hacks.org | http://www.unmaintained-free-software.org
> 
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-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.