mirror of
https://github.com/RaySollium99/picodrive.git
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146 lines
3.2 KiB
C
146 lines
3.2 KiB
C
// This is part of Pico Library
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// (c) Copyright 2004 Dave, All rights reserved.
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// (c) Copyright 2006 notaz, All rights reserved.
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// Free for non-commercial use.
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// For commercial use, separate licencing terms must be obtained.
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#include "../PicoInt.h"
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int SekCycleCntS68k=0; // cycles done in this frame
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int SekCycleAimS68k=0; // cycle aim
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#ifdef EMU_C68K
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// ---------------------- Cyclone 68000 ----------------------
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struct Cyclone PicoCpuS68k;
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#endif
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#ifdef EMU_M68K
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// ---------------------- MUSASHI 68000 ----------------------
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m68ki_cpu_core PicoS68kCPU; // Mega CD's CPU
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#endif
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static int new_irq_level(int level)
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{
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int level_new = 0, irqs;
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Pico_mcd->m.s68k_pend_ints &= ~(1 << level);
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irqs = Pico_mcd->m.s68k_pend_ints;
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irqs &= Pico_mcd->s68k_regs[0x33];
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while ((irqs >>= 1)) level_new++;
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return level_new;
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}
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#ifdef EMU_M68K
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static int SekIntAckS68k(int level)
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{
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int level_new = new_irq_level(level);
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dprintf("s68kACK %i -> %i", level, level_new);
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CPU_INT_LEVEL = level_new << 8;
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return M68K_INT_ACK_AUTOVECTOR;
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}
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#endif
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#ifdef EMU_C68K
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// interrupt acknowledgment
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static void SekIntAckS68k(int level)
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{
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int level_new = new_irq_level(level);
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dprintf("s68kACK %i -> %i", level, level_new);
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PicoCpuS68k.irq = level_new;
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}
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static void SekResetAck()
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{
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dprintf("s68k: Reset encountered @ %06x", SekPcS68k);
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}
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static int SekUnrecognizedOpcode()
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{
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unsigned int pc, op;
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pc = SekPcS68k;
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op = PicoCpuS68k.read16(pc);
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dprintf("Unrecognized Opcode %04x @ %06x", op, pc);
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//exit(1);
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return 0;
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}
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#endif
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int SekInitS68k()
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{
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#ifdef EMU_C68K
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// CycloneInit();
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memset(&PicoCpuS68k,0,sizeof(PicoCpuS68k));
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PicoCpuS68k.IrqCallback=SekIntAckS68k;
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PicoCpuS68k.ResetCallback=SekResetAck;
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PicoCpuS68k.UnrecognizedCallback=SekUnrecognizedOpcode;
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#endif
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#ifdef EMU_M68K
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{
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// Musashi is not very context friendly..
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void *oldcontext = m68ki_cpu_p;
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m68k_set_context(&PicoS68kCPU);
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m68k_set_cpu_type(M68K_CPU_TYPE_68000);
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m68k_init();
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m68k_set_int_ack_callback(SekIntAckS68k);
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// m68k_pulse_reset(); // not yet, memmap is not set up
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m68k_set_context(oldcontext);
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}
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#endif
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return 0;
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}
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// Reset the 68000:
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int SekResetS68k()
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{
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if (Pico.rom==NULL) return 1;
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#ifdef EMU_C68K
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PicoCpuS68k.stopped=0;
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PicoCpuS68k.osp=0;
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PicoCpuS68k.srh =0x27; // Supervisor mode
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PicoCpuS68k.flags=4; // Z set
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PicoCpuS68k.irq=0;
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PicoCpuS68k.a[7]=PicoCpuS68k.read32(0); // Stack Pointer
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PicoCpuS68k.membase=0;
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PicoCpuS68k.pc=PicoCpuS68k.checkpc(PicoCpuS68k.read32(4)); // Program Counter
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#endif
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#ifdef EMU_M68K
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{
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void *oldcontext = m68ki_cpu_p;
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m68k_set_context(&PicoS68kCPU);
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m68k_pulse_reset();
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m68k_set_context(oldcontext);
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}
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#endif
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return 0;
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}
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int SekInterruptS68k(int irq)
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{
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int irqs, real_irq = 1;
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Pico_mcd->m.s68k_pend_ints |= 1 << irq;
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irqs = Pico_mcd->m.s68k_pend_ints >> 1;
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while ((irqs >>= 1)) real_irq++; // this is probably only needed for Cyclone
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#ifdef EMU_C68K
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PicoCpuS68k.irq=real_irq;
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#endif
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#ifdef EMU_M68K
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void *oldcontext = m68ki_cpu_p;
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m68k_set_context(&PicoS68kCPU);
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m68k_set_irq(real_irq); // raise irq (gets lowered after taken or must be done in ack)
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m68k_set_context(oldcontext);
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#endif
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return 0;
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}
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