macdev.c

/*MAC Psuedo Device for Mac -> Vax communication*/
#include <types.h>

#define _MACDEV_C_

#include "mmemory.h"
#include "macdev.h"

#pragma segment MAC_DEVICE

long set_macvax_interrupt
(
	long command
)
{
	/*Set up an interrupt*/
	IPR(MVCR) = (unsigned long)command;
	/*Check for overflow*/
	if(IPR(MVCS) & MVCS_INT_BIT)
		IPR(MVCS) |= MVCS_ERR_BIT;
	else
		/*Set the Interrupt bit*/	
		IPR(MVCS) |= MVCS_INT_BIT;

	if(MVCS_INT_ENB(IPR(MVCS)) == 0)
	{	/*system doesn't want interrupts*/
		return 0;
	}
	else
	{	/*Set up the interrupt*/
		IPR(SISR) |= MACVAX_INTERRUPT_BIT; 	/*IPL 23*/	
		return 1;
	}
}

void 
clear_macvax_interrupt(void)
{	/*clear the MVCS registers interrupt bit, leaving the system SISR alone	*/
	/*We can't alter the SISR as something else might have requested a level*/
	/* 23 interrupt															*/
		IPR(MVCS) &= ~MVCS_INT_BIT;
}

/*return vector address for MACVAX interrupt*/
address 
macvax_interrupt(void)
{
	if(MVCS_INT( IPR(MVCS) ) == 0) /*covers the case where we cancel the interrupt*/
		return (address) 0;
	else
		return (address) V_MACVAX;
}