home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Atari Mega Archive 1
/
Atari Mega Archive - Volume 1.iso
/
telecomm
/
sticpsrc.lzh
/
SOURCE.ARC
/
PCIRQ.C
< prev
next >
Wrap
C/C++ Source or Header
|
1989-08-10
|
2KB
|
106 lines
/* Hardware interrupt dependent stuff for IBM-PC running MS-DOS */
#include "global.h"
/* This flag is set by setirq() if IRQ 8-15 is used, indicating
* that the machine is a PC/AT with a second 8259 interrupt controller.
* If this flag is set, the interrupt return code in pcgen.asm will
* send an End of Interrupt command to the second 8259 as well as the
* first.
*/
extern char isat;
/* Install hardware interrupt handler.
* Takes IRQ numbers from 0-7 (0-15 on AT) and maps to actual 8086/286 vectors
* Note that bus line IRQ2 maps to IRQ9 on the AT
*/
setirq(irq,handler)
unsigned irq;
void (*handler)();
{
/* Set interrupt vector */
if(irq < 8){
setvect(8+irq,handler);
} else if(irq < 16){
isat = 1;
setvect(0x70 + irq - 8,handler);
} else {
return -1;
}
return 0;
}
/* Return pointer to hardware interrupt handler.
* Takes IRQ numbers from 0-7 (0-15 on AT) and maps to actual 8086/286 vectors
*/
void
(*getirq(irq))()
unsigned int irq;
{
void (*getvect())();
/* Set interrupt vector */
if(irq < 8){
return getvect(8+irq);
} else if(irq < 16){
return getvect(0x70 + irq - 8);
} else {
return NULLVFP;
}
}
/* Disable hardware interrupt */
maskoff(irq)
unsigned irq;
{
if(irq < 8){
setbit(0x21,(char)(1<<irq));
} else if(irq < 16){
irq -= 8;
setbit(0xa1,(char)(1<<irq));
} else {
return -1;
}
return 0;
}
/* Enable hardware interrupt */
maskon(irq)
unsigned irq;
{
if(irq < 8){
clrbit(0x21,(char)(1<<irq));
} else if(irq < 16){
irq -= 8;
clrbit(0xa1,(char)(1<<irq));
} else {
return -1;
}
return 0;
}
/* Return 1 if specified interrupt is enabled, 0 if not, -1 if invalid */
getmask(irq)
unsigned irq;
{
if(irq < 8)
return (inportb(0x21) & (1 << irq)) ? 0 : 1;
else if(irq < 16){
irq -= 8;
return (inportb(0xa1) & (1 << irq)) ? 0 : 1;
} else
return -1;
}
/* Set bit(s) in I/O port */
setbit(port,bits)
unsigned port;
char bits;
{
outportb(port,(char)inportb(port)|bits);
}
/* Clear bit(s) in I/O port */
clrbit(port,bits)
unsigned port;
char bits;
{
outportb(port,(char)(inportb(port) & ~bits));
}