blob: 80ae62dcbb796d7814c25a80fe1084e81d6abf0c (
plain)
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
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/***********************************************************************
*
* Name: sys_sppt.c
*
* Purpose: Support Routines for Modules 3 and 4 of MPX-PC
*
* Sample Call:
* sys_init()
* sys_exit()
*
* Procedures In Module:
* sys_init - Sets up interrupt vector 60 for MPX-PC
* sys_exit - Resets interrupt vector 60 and exits to DOS
*
*
****************************************************************************/
#include <stdio.h>
#include <dos.h>
#include "mpx.h"
void interrupt (*vect60)(); /* Storage for DOS int 60h */
/* interrupt vector. */
void sys_init()
{
/* set up interrupt vector for MPX sys_calls */
vect60 = getvect(0x60);
setvect(0x60,&sys_call);
}
void sys_exit()
{
/* restore interrupt vector 60 and exit */
setvect(0x60,vect60);
exit();
}
void interrupt dispatch()
{
/* MOD 4 dispatch */
do {
cop = cop -> next;
} while (cop != NULL && cop->suspend == SUSPENDED);
if (cop == NULL) {
_SP = sp_save;
} else {
_SP = cop -> stack_ptr;
}
}
void interrupt sys_call()
{
struct parm {
int op_number;
int op_type;
char *buffer;
int *length;
};
static struct parm *parm_add;
/* Save stack pointer for current process */
cop->stack_ptr = _SP;
/* Get address of sys_call parameters */
parm_add = _SP + 0x1c; // parameter offset = 0x1C
/* Note that you should save this parameter address
somewhere in the pcb as suggested below*/
cop->parm_add = parm_add;
// find out if the process wants to die... and kill it
if (parm_add->op_number == EXIT_CODE) {
cop->suspend = SUSPENDED;
}
dispatch();
}
|
