cmos.c File Reference

x86: the PC's real time clock, in the CMOS: the date and time, which the kernel reads to set its clock at boot (arch_time_get()). More...

#include <core/system.h>
#include <core/types.h>
#include <cpu/io.h>

Go to the source code of this file.

Data Structures
struct	cmos_rtc
	The real time clock's date and time, as it keeps them. More...

Macros
#define	RTC_SEC   0x00
#define	RTC_MIN   0x02
#define	RTC_HRS   0x04
#define	RTC_WD   0x06
#define	RTC_DOM   0x07
#define	RTC_MON   0x08
#define	RTC_YR   0x09
#define	RTC_SA   0x0A
#define	RTC_SB   0x0B
#define	RTC_UIP   0x80
#define	RTC_24H   0x02
#define	RTC_BIN   0x04
#define	RTC_PM   0x80

Functions
static uint8_t	cmos_reg_read (uint8_t reg)
	Reads a CMOS register.
static uint8_t	bcd_to_bin (uint8_t bcd)
	Converts a BCD byte to binary.
static int	cmos_time (struct cmos_rtc *rtc)
	Reads the real time clock's date and time, in binary and in 24-hour time.
int	arch_time_get (struct timespec *ts)
	Reads the date and time from the real time clock.
int	x86_cmos_setup (struct ioaddr *ioaddr)
	Sets where the CMOS's ports are.

Variables
static struct ioaddr	cmos

Detailed Description

x86: the PC's real time clock, in the CMOS: the date and time, which the kernel reads to set its clock at boot (arch_time_get()).

The year is taken to be in the 2000s (the century register isn't read).

Definition in file cmos.c.

Macro Definition Documentation

RTC_24H

#define RTC_24H   0x02

Definition at line 22 of file cmos.c.

Referenced by cmos_time().

RTC_BIN

#define RTC_BIN   0x04

Definition at line 23 of file cmos.c.

Referenced by cmos_time().

RTC_DOM

#define RTC_DOM   0x07

Definition at line 15 of file cmos.c.

Referenced by cmos_time().

RTC_HRS

#define RTC_HRS   0x04

Definition at line 13 of file cmos.c.

Referenced by cmos_time().

RTC_MIN

#define RTC_MIN   0x02

Definition at line 12 of file cmos.c.

Referenced by cmos_time().

RTC_MON

#define RTC_MON   0x08

Definition at line 16 of file cmos.c.

Referenced by cmos_time().

RTC_PM

#define RTC_PM   0x80

Definition at line 24 of file cmos.c.

Referenced by cmos_time().

RTC_SA

#define RTC_SA   0x0A

Definition at line 18 of file cmos.c.

Referenced by cmos_time().

RTC_SB

#define RTC_SB   0x0B

Definition at line 19 of file cmos.c.

Referenced by cmos_time().

RTC_SEC

#define RTC_SEC   0x00

Definition at line 11 of file cmos.c.

Referenced by cmos_time().

RTC_UIP

#define RTC_UIP   0x80

Definition at line 21 of file cmos.c.

Referenced by cmos_time().

RTC_WD

#define RTC_WD   0x06

Definition at line 14 of file cmos.c.

Referenced by cmos_time().

RTC_YR

#define RTC_YR   0x09

Definition at line 17 of file cmos.c.

Referenced by cmos_time().

Function Documentation

arch_time_get()

int arch_time_get

(

struct timespec *

ts

)

Reads the date and time from the real time clock.

Parameters

ts	set to the time since the epoch, to the second (tv_nsec is 0)

Returns

0

Definition at line 100 of file cmos.c.

References arch_time_get(), cmos_time(), cmos_rtc::hrs, cmos_rtc::mday, cmos_rtc::min, cmos_rtc::mon, cmos_rtc::sec, timespec::tv_nsec, timespec::tv_sec, and cmos_rtc::yr.

bcd_to_bin()

uint8_t bcd_to_bin ( uint8_t bcd )

inlinestatic

Converts a BCD byte to binary.

Definition at line 48 of file cmos.c.

References bcd_to_bin().

Referenced by bcd_to_bin(), and cmos_time().

cmos_reg_read()

uint8_t cmos_reg_read ( uint8_t reg )

static

Reads a CMOS register.

Bit 7 of the index port disables NMIs while it is set, so it is left clear: setting it would mask them from then on.

Definition at line 30 of file cmos.c.

References cmos, cmos_reg_read(), io_in8(), and io_out8().

Referenced by cmos_reg_read(), and cmos_time().

cmos_time()

int cmos_time ( struct cmos_rtc * rtc )

static

Reads the real time clock's date and time, in binary and in 24-hour time.

Returns 0.

Definition at line 55 of file cmos.c.

References bcd_to_bin(), cmos_reg_read(), cmos_time(), cmos_rtc::hrs, cmos_rtc::mday, cmos_rtc::min, cmos_rtc::mon, RTC_24H, RTC_BIN, RTC_DOM, RTC_HRS, RTC_MIN, RTC_MON, RTC_PM, RTC_SA, RTC_SB, RTC_SEC, RTC_UIP, RTC_WD, RTC_YR, cmos_rtc::sec, cmos_rtc::wday, and cmos_rtc::yr.

Referenced by arch_time_get(), and cmos_time().

x86_cmos_setup()

int x86_cmos_setup

(

struct ioaddr *

ioaddr

)

Sets where the CMOS's ports are.

Parameters

ioaddr

its index and data ports (0x70)

Returns

0

Definition at line 139 of file cmos.c.

References ioaddr::addr, cmos, ioaddr_type_str(), printk(), and x86_cmos_setup().

Referenced by x86_cmos_setup(), and x86_pc_cmos_init().

Variable Documentation

cmos

struct ioaddr cmos

static

Definition at line 26 of file cmos.c.

Referenced by cmos_reg_read(), and x86_cmos_setup().