Date: Sat, 11 Jul 1998 08:41:51 +1000 (EST) From: peter.jeremyp@alcatel.com.au To: FreeBSD-gnats-submit@FreeBSD.ORG Subject: kern/7242: Clarification of comments in RTC header Message-ID: <199807102241.IAA15123@vk2pj.alcatel.com.au>
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>Number: 7242 >Category: kern >Synopsis: Clarification of comments in RTC header >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: change-request >Submitter-Id: current-users >Arrival-Date: Fri Jul 10 15:50:02 PDT 1998 >Last-Modified: >Originator: Peter Jeremy >Organization: >Release: FreeBSD 2.2.5-RELEASE i386 >Environment: Any FreeBSD 2.x (and maybe 3.x) >Description: The comments in sys/i386/isa/rtc.h are less clear than they could be. Adding the following reduces the requirement to refer to the MC146818 data sheet to determine the code behaviour. >How-To-Repeat: Look at the source and patch below. >Fix: The following is a patch to 2.2.5-RELEASE or 2.2.6-RELEASE which will clarify a number of comments. diff -ur 2.2.6/sys/i386/isa/rtc.h 2.2.5/sys/i386/isa/rtc.h --- 2.2.6/sys/i386/isa/rtc.h Tue Oct 10 01:00:39 1995 +++ 2.2.5/sys/i386/isa/rtc.h Sat Jan 17 19:26:14 1998 @@ -40,14 +40,8 @@ #ifndef _I386_ISA_RTC_H_ #define _I386_ISA_RTC_H_ 1 /* - * RTC Register locations + * MC146818 RTC Register locations */ #define RTC_SEC 0x00 /* seconds */ @@ -57,8 +57,9 @@ #define RTC_STATUSA 0x0a /* status register A */ #define RTCSA_TUP 0x80 /* time update, don't look now */ +#define RTCSA_RESET 0x70 /* reset divider */ #define RTCSA_DIVIDER 0x20 /* divider correct for 32768 Hz */ -#define RTCSA_8192 0x03 +#define RTCSA_8192 0x03 /* 8192 Hz interrupt */ #define RTCSA_4096 0x04 #define RTCSA_2048 0x05 #define RTCSA_1024 0x06 /* default for profiling */ @@ -70,17 +71,17 @@ #define RTCSA_NOPROF RTCSA_128 #define RTC_NOPROFRATE 128 #define RTCSA_64 0x0a -#define RTCSA_32 0x0b +#define RTCSA_32 0x0b /* 32Hz interrupt */ #define RTC_STATUSB 0x0b /* status register B */ -#define RTCSB_DST 0x01 /* Daylight Savings Time enable */ +#define RTCSB_DST 0x01 /* USA Daylight Savings Time enable */ #define RTCSB_24HR 0x02 /* 0 = 12 hours, 1 = 24 hours */ #define RTCSB_BCD 0x04 /* 0 = BCD, 1 = Binary coded time */ #define RTCSB_SQWE 0x08 /* 1 = output sqare wave at SQW pin */ #define RTCSB_UINTR 0x10 /* 1 = enable update-ended interrupt */ #define RTCSB_AINTR 0x20 /* 1 = enable alarm interrupt */ #define RTCSB_PINTR 0x40 /* 1 = enable periodic clock interrupt */ -#define RTCSB_HALT 0x80 /* stop clock updates */ +#define RTCSB_HALT 0x80 /* 1 = stop clock updates */ #define RTC_INTR 0x0c /* status register C (R) interrupt source */ #define RTCIR_UPDATE 0x10 /* update intr */ @@ -89,8 +90,9 @@ #define RTCIR_INT 0x80 /* interrupt output signal */ #define RTC_STATUSD 0x0d /* status register D (R) Lost Power */ -#define RTCSD_PWR 0x80 /* clock lost power */ +#define RTCSD_PWR 0x80 /* 0 = clock lost power */ +/* everything below here is CMOS RAM */ #define RTC_DIAG 0x0e /* status register E - bios diagnostic */ #define RTCDG_BITS "\020\010clock_battery\007ROM_cksum\006config_unit\005memory_size\004fixed_disk\003invalid_time" >Audit-Trail: >Unformatted: To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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