kclock.h

/* See COPYRIGHT for copyright information. */

#ifndef JOS_KERN_KCLOCK_H
#define JOS_KERN_KCLOCK_H
#ifndef JOS_KERNEL
# error "This is a JOS kernel header; user programs should not #include it"
#endif

#define	IO_RTC		0x070		/* RTC port */

#define	MC_NVRAM_START	0xe	/* start of NVRAM: offset 14 */
#define	MC_NVRAM_SIZE	50	/* 50 bytes of NVRAM */

/* NVRAM bytes 7 & 8: base memory size */
#define NVRAM_BASELO	(MC_NVRAM_START + 7)	/* low byte; RTC off. 0x15 */
#define NVRAM_BASEHI	(MC_NVRAM_START + 8)	/* high byte; RTC off. 0x16 */

/* NVRAM bytes 9 & 10: extended memory size (between 1MB and 16MB) */
#define NVRAM_EXTLO	(MC_NVRAM_START + 9)	/* low byte; RTC off. 0x17 */
#define NVRAM_EXTHI	(MC_NVRAM_START + 10)	/* high byte; RTC off. 0x18 */

/* NVRAM bytes 38 and 39: extended memory size (between 16MB and 4G) */
#define NVRAM_EXT16LO	(MC_NVRAM_START + 38)	/* low byte; RTC off. 0x34 */
#define NVRAM_EXT16HI	(MC_NVRAM_START + 39)	/* high byte; RTC off. 0x35 */

unsigned mc146818_read(unsigned reg);
void mc146818_write(unsigned reg, unsigned datum);

#endif	// !JOS_KERN_KCLOCK_H