mirror of
https://github.com/RaySollium99/picodrive.git
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124 lines
2.5 KiB
C
124 lines
2.5 KiB
C
/*
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* PicoDrive
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* (C) notaz, 2009,2010
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*
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* This work is licensed under the terms of MAME license.
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* See COPYING file in the top-level directory.
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*/
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#include <string.h>
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#include <stddef.h>
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#include "sh2.h"
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#include "../debug.h"
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#include "compiler.h"
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#define I 0xf0
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SH2 *sh2; // active sh2
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int sh2_init(SH2 *sh2, int is_slave)
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{
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int ret = 0;
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memset(sh2, 0, offsetof(SH2, mult_m68k_to_sh2));
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sh2->is_slave = is_slave;
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pdb_register_cpu(sh2, PDBCT_SH2, is_slave ? "ssh2" : "msh2");
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#ifdef DRC_SH2
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ret = sh2_drc_init(sh2);
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#endif
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return ret;
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}
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void sh2_finish(SH2 *sh2)
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{
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#ifdef DRC_SH2
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sh2_drc_finish(sh2);
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#endif
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}
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void sh2_reset(SH2 *sh2)
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{
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sh2->pc = p32x_sh2_read32(0, sh2);
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sh2->r[15] = p32x_sh2_read32(4, sh2);
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sh2->sr = I;
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sh2->vbr = 0;
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sh2->pending_int_irq = 0;
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}
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void sh2_do_irq(SH2 *sh2, int level, int vector)
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{
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sh2->r[15] -= 4;
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p32x_sh2_write32(sh2->r[15], sh2->sr, sh2); /* push SR onto stack */
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sh2->r[15] -= 4;
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p32x_sh2_write32(sh2->r[15], sh2->pc, sh2); /* push PC onto stack */
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/* set I flags in SR */
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sh2->sr = (sh2->sr & ~I) | (level << 4);
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/* fetch PC */
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sh2->pc = p32x_sh2_read32(sh2->vbr + vector * 4, sh2);
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/* 13 cycles at best */
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sh2->m68krcycles_done += C_SH2_TO_M68K(*sh2, 13);
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// sh2->icount -= 13;
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}
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int sh2_irl_irq(SH2 *sh2, int level, int nested_call)
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{
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int taken;
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sh2->pending_irl = level;
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if (level < sh2->pending_int_irq)
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level = sh2->pending_int_irq;
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sh2->pending_level = level;
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taken = (level > ((sh2->sr >> 4) & 0x0f));
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if (taken) {
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if (!nested_call) {
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// not in memhandler, so handle this now (recompiler friendly)
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// do this to avoid missing irqs that other SH2 might clear
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int vector = sh2->irq_callback(sh2, level);
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sh2_do_irq(sh2, level, vector);
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}
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else
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sh2->test_irq = 1;
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}
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return taken;
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}
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void sh2_internal_irq(SH2 *sh2, int level, int vector)
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{
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// FIXME: multiple internal irqs not handled..
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// assuming internal irqs never clear until accepted
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sh2->pending_int_irq = level;
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sh2->pending_int_vector = vector;
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if (level > sh2->pending_level)
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sh2->pending_level = level;
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sh2->test_irq = 1;
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}
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#define SH2_REG_SIZE (offsetof(SH2, macl) + sizeof(sh2->macl))
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void sh2_pack(const SH2 *sh2, unsigned char *buff)
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{
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unsigned int *p;
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memcpy(buff, sh2, SH2_REG_SIZE);
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p = (void *)(buff + SH2_REG_SIZE);
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p[0] = sh2->pending_int_irq;
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p[1] = sh2->pending_int_vector;
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}
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void sh2_unpack(SH2 *sh2, const unsigned char *buff)
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{
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unsigned int *p;
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memcpy(sh2, buff, SH2_REG_SIZE);
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p = (void *)(buff + SH2_REG_SIZE);
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sh2->pending_int_irq = p[0];
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sh2->pending_int_vector = p[1];
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}
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