jos/kern/kclock.h
Anish Athalye 2d1187aa3c Lab 2
2018-09-12 14:55:07 -04:00

30 lines
1.1 KiB
C

/* 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