Date: Sun, 23 Jul 2017 21:28:00 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r321400 - head/sys/kern Message-ID: <201707232128.v6NLS0Gs016213@repo.freebsd.org>
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Author: ian Date: Sun Jul 23 21:28:00 2017 New Revision: 321400 URL: https://svnweb.freebsd.org/changeset/base/321400 Log: Add common code to support realtime clocks that store year without century. Most realtime clocks store the year as 2 BCD digits. Some add a century bit to extend the range another hundred years. Every clock driver has its own code to determine the century and pass a full year value to clock_ct_to_ts(). Now clock drivers can just convert BCD to bin and store the result in the clocktime struct and let the common code figure out the century. Clocks with a century bit can just add 100 to year if the century bit is on. Modified: head/sys/kern/subr_clock.c Modified: head/sys/kern/subr_clock.c ============================================================================== --- head/sys/kern/subr_clock.c Sun Jul 23 20:41:58 2017 (r321399) +++ head/sys/kern/subr_clock.c Sun Jul 23 21:28:00 2017 (r321400) @@ -142,18 +142,27 @@ clock_ct_to_ts(struct clocktime *ct, struct timespec * { int i, year, days; - year = ct->year; - if (ct_debug) { printf("ct_to_ts("); print_ct(ct); printf(")"); } + /* + * Many realtime clocks store the year as 2-digit BCD; pivot on 70 to + * determine century. Some clocks have a "century bit" and drivers do + * year += 100, so interpret values between 70-199 as relative to 1900. + */ + year = ct->year; + if (year < 70) + year += 2000; + else if (year < 200) + year += 1900; + /* Sanity checks. */ if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || ct->day > days_in_month(year, ct->mon) || - ct->hour > 23 || ct->min > 59 || ct->sec > 59 || + ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 || (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ if (ct_debug) printf(" = EINVAL\n");
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