mirror of
https://github.com/ksherlock/mpw.git
synced 2024-06-06 19:29:45 +00:00
108 lines
4.1 KiB
C
108 lines
4.1 KiB
C
/* @(#) $Id: CpuModule_Interrupts.c,v 1.5 2012/08/12 16:51:02 peschau Exp $ */
|
|
/*=========================================================================*/
|
|
/* Fellow */
|
|
/* 68000 interrupt handling */
|
|
/* */
|
|
/* Author: Petter Schau */
|
|
/* */
|
|
/* Copyright (C) 1991, 1992, 1996 Free Software Foundation, Inc. */
|
|
/* */
|
|
/* This program is free software; you can redistribute it and/or modify */
|
|
/* it under the terms of the GNU General Public License as published by */
|
|
/* the Free Software Foundation; either version 2, or (at your option) */
|
|
/* any later version. */
|
|
/* */
|
|
/* This program is distributed in the hope that it will be useful, */
|
|
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
|
|
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
|
|
/* GNU General Public License for more details. */
|
|
/* */
|
|
/* You should have received a copy of the GNU General Public License */
|
|
/* along with this program; if not, write to the Free Software Foundation, */
|
|
/* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
|
/*=========================================================================*/
|
|
#include "defs.h"
|
|
#include "fellow.h"
|
|
#include "fmem.h"
|
|
|
|
#include "CpuModule.h"
|
|
#include "CpuModule_Internal.h"
|
|
|
|
/* Function for checking pending interrupts */
|
|
cpuCheckPendingInterruptsFunc cpu_check_pending_interrupts_func;
|
|
|
|
void cpuCallCheckPendingInterruptsFunc(void)
|
|
{
|
|
if (cpuGetRaiseInterrupt()) return;
|
|
cpuSetRaiseInterrupt(cpu_check_pending_interrupts_func());
|
|
}
|
|
|
|
void cpuCheckPendingInterrupts(void)
|
|
{
|
|
cpuCallCheckPendingInterruptsFunc();
|
|
}
|
|
|
|
void cpuSetCheckPendingInterruptsFunc(cpuCheckPendingInterruptsFunc func)
|
|
{
|
|
cpu_check_pending_interrupts_func = func;
|
|
}
|
|
|
|
ULO cpuActivateSSP(void)
|
|
{
|
|
ULO currentSP = cpuGetAReg(7);
|
|
|
|
// check supervisor bit number (bit 13) within the system byte of the status register
|
|
if (!cpuGetFlagSupervisor())
|
|
{
|
|
// we are in user mode, thus save user stack pointer (USP)
|
|
cpuSetUspDirect(currentSP);
|
|
currentSP = cpuGetSspDirect();
|
|
|
|
if (cpuGetModelMajor() >= 2)
|
|
{
|
|
if (cpuGetFlagMaster())
|
|
{
|
|
currentSP = cpuGetMspDirect();
|
|
}
|
|
}
|
|
cpuSetAReg(7, currentSP);
|
|
}
|
|
return currentSP;
|
|
}
|
|
|
|
/*============================================================
|
|
Transfers control to an interrupt routine
|
|
============================================================*/
|
|
|
|
// Returns TRUE if the cpu was stopped
|
|
void cpuSetUpInterrupt(void)
|
|
{
|
|
UWO vector_offset = (UWO) (0x60 + cpuGetIrqLevel()*4);
|
|
cpuActivateSSP(); // Switch to using ssp or msp. Loads a7 and preserves usp if we came from user-mode.
|
|
|
|
cpuStackFrameGenerate(vector_offset, cpuGetPC()); // This will end up on msp if master is enabled, or on the ssp/isp if not.
|
|
|
|
cpuSetSR(cpuGetSR() & 0x38ff); // Clear interrupt level
|
|
cpuSetSR(cpuGetSR() | 0x2000); // Set supervisor mode
|
|
cpuSetSR(cpuGetSR() | (UWO)(cpuGetIrqLevel() << 8)); // Set interrupt level
|
|
|
|
#ifdef CPU_INSTRUCTION_LOGGING
|
|
cpuCallInterruptLoggingFunc(cpuGetIrqLevel(), cpuGetIrqAddress());
|
|
#endif
|
|
|
|
if (cpuGetModelMajor() >= 2 && cpuGetModelMajor() < 6)
|
|
{
|
|
if (cpuGetFlagMaster())
|
|
{ // If the cpu was in master mode, preserve msp, and switch to using ssp (isp) in a7.
|
|
ULO oldA7 = cpuGetAReg(7);
|
|
cpuSetMspDirect(oldA7);
|
|
cpuSetAReg(7, cpuGetSspDirect());
|
|
cpuFrame1(vector_offset, cpuGetPC()); // Make the throwaway frame on ssp/isp
|
|
cpuSetSR(cpuGetSR() & 0xefff); // Clear master bit
|
|
}
|
|
}
|
|
cpuInitializeFromNewPC(cpuGetIrqAddress());
|
|
cpuSetStop(FALSE);
|
|
cpuSetRaiseInterrupt(FALSE);
|
|
}
|