~kris/9p

9hist

ref: b7ea96cf198d50dd3ca528b2fd280f74e1b72015 9hist/pc/headland.c -rw-r--r-- 467 bytes
b7ea96cf — David du Colombier Plan 9 from Bell Labs 1992-05-29 34 years ago
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
#include	"u.h"
#include	"../port/lib.h"
#include	"mem.h"
#include	"dat.h"
#include	"fns.h"
#include	"io.h"

/*
 *  headland system controller (ht21)
 */
enum
{
	/*
	 *  system control port
	 */
	Head=		0x92,		/* control port */
	 Reset=		(1<<0),		/* reset the 386 */
	 A20ena=	(1<<1),		/* enable address line 20 */
};

/*
 *  enable address bit 20
 */
void
heada20(void)
{
	outb(Head, A20ena);
}

/*
 *  reset machine
 */
void
headreset(void)
{
	outb(Head, Reset);
}