mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-11-13 22:35:10 +01:00
28775cc3aa
---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup. [Core/SCD] ---------- * added Mega CD / Sega CD hardware emulation (incl. Sub 68K, CDD, CDC, PCM, GFX rotation/scaling, etc) * added .ISO & .BIN CD image file support * added 512K backup cartridge RAM support * added savestate support for CD games NOTES: ~~~~~~ * to play CD games, original BIOS ROM files are required in /genplus/bios/ directory: unzip & rename them to bios_CD_U.bin, bios_CD_E.bin, bios_CD_J.bin * CD audio tracks (CD-DA) are not supported (yet) [Core/CPU] ---------- * modified 68k core for Mega CD / Sega CD support [Core/VDP] --------------- * improved DMA accuracy * added support for 8-bit VRAM writes with undocumented code value (verified on real hardware by Nemesis) [Gamecube/Wii] --------------- * modified Master System & Game Gear "BIOS" support (files should be named bios_U.sms, bios_J.sms, bios_E.sms & bios.gg and copied to /genplus/bios directory). * replaced "Hard Reset" button by a Soft Reset for systems having a Reset button (Mega Drive / Genesis & Master System) * State & SRAM files are now only compressed when saving to Gamecube Memory Cards * various fixes & cleanup.
341 lines
10 KiB
C
341 lines
10 KiB
C
/* ======================================================================== */
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/* SUB 68K CORE */
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/* ======================================================================== */
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extern int scd_68k_irq_ack(int level);
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#define m68ki_cpu s68k
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#define MUL (4)
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/* ======================================================================== */
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/* ================================ INCLUDES ============================== */
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/* ======================================================================== */
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#ifndef BUILD_TABLES
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#include "s68ki_cycles.h"
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#endif
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#include "s68kconf.h"
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#include "m68kcpu.h"
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#include "m68kops.h"
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/* ======================================================================== */
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/* ================================= DATA ================================= */
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/* ======================================================================== */
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#ifdef BUILD_TABLES
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static unsigned char s68ki_cycles[0x10000];
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#endif
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static int irq_latency;
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/* IRQ priority */
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static const uint8 irq_level[0x40] =
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{
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0, 1, 2, 2, 3, 3, 3, 3,
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4, 4, 4, 4, 4, 4, 4, 4,
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5, 5, 5, 5, 5, 5, 5, 5,
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5, 5, 5, 5, 5, 5, 5, 5,
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6, 6, 6, 6, 6, 6, 6, 6,
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6, 6, 6, 6, 6, 6, 6, 6,
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6, 6, 6, 6, 6, 6, 6, 6,
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6, 6, 6, 6, 6, 6, 6, 6
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};
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m68ki_cpu_core s68k;
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/* ======================================================================== */
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/* =============================== CALLBACKS ============================== */
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/* ======================================================================== */
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/* Default callbacks used if the callback hasn't been set yet, or if the
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* callback is set to NULL
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*/
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#if M68K_EMULATE_INT_ACK == OPT_ON
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/* Interrupt acknowledge */
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static int default_int_ack_callback(int int_level)
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{
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CPU_INT_LEVEL = 0;
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return M68K_INT_ACK_AUTOVECTOR;
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}
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#endif
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#if M68K_EMULATE_RESET == OPT_ON
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/* Called when a reset instruction is executed */
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static void default_reset_instr_callback(void)
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{
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}
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#endif
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#if M68K_TAS_HAS_CALLBACK == OPT_ON
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/* Called when a tas instruction is executed */
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static int default_tas_instr_callback(void)
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{
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return 1; // allow writeback
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}
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#endif
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#if M68K_EMULATE_FC == OPT_ON
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/* Called every time there's bus activity (read/write to/from memory */
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static void default_set_fc_callback(unsigned int new_fc)
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{
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}
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#endif
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/* ======================================================================== */
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/* ================================= API ================================== */
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/* ======================================================================== */
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/* Access the internals of the CPU */
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unsigned int s68k_get_reg(m68k_register_t regnum)
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{
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switch(regnum)
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{
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case M68K_REG_D0: return m68ki_cpu.dar[0];
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case M68K_REG_D1: return m68ki_cpu.dar[1];
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case M68K_REG_D2: return m68ki_cpu.dar[2];
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case M68K_REG_D3: return m68ki_cpu.dar[3];
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case M68K_REG_D4: return m68ki_cpu.dar[4];
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case M68K_REG_D5: return m68ki_cpu.dar[5];
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case M68K_REG_D6: return m68ki_cpu.dar[6];
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case M68K_REG_D7: return m68ki_cpu.dar[7];
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case M68K_REG_A0: return m68ki_cpu.dar[8];
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case M68K_REG_A1: return m68ki_cpu.dar[9];
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case M68K_REG_A2: return m68ki_cpu.dar[10];
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case M68K_REG_A3: return m68ki_cpu.dar[11];
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case M68K_REG_A4: return m68ki_cpu.dar[12];
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case M68K_REG_A5: return m68ki_cpu.dar[13];
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case M68K_REG_A6: return m68ki_cpu.dar[14];
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case M68K_REG_A7: return m68ki_cpu.dar[15];
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case M68K_REG_PC: return MASK_OUT_ABOVE_32(m68ki_cpu.pc);
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case M68K_REG_SR: return m68ki_cpu.t1_flag |
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(m68ki_cpu.s_flag << 11) |
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m68ki_cpu.int_mask |
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((m68ki_cpu.x_flag & XFLAG_SET) >> 4) |
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((m68ki_cpu.n_flag & NFLAG_SET) >> 4) |
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((!m68ki_cpu.not_z_flag) << 2) |
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((m68ki_cpu.v_flag & VFLAG_SET) >> 6) |
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((m68ki_cpu.c_flag & CFLAG_SET) >> 8);
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case M68K_REG_SP: return m68ki_cpu.dar[15];
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case M68K_REG_USP: return m68ki_cpu.s_flag ? m68ki_cpu.sp[0] : m68ki_cpu.dar[15];
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case M68K_REG_ISP: return m68ki_cpu.s_flag ? m68ki_cpu.dar[15] : m68ki_cpu.sp[4];
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#if M68K_EMULATE_PREFETCH
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case M68K_REG_PREF_ADDR: return m68ki_cpu.pref_addr;
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case M68K_REG_PREF_DATA: return m68ki_cpu.pref_data;
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#endif
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case M68K_REG_IR: return m68ki_cpu.ir;
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default: return 0;
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}
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}
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void s68k_set_reg(m68k_register_t regnum, unsigned int value)
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{
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switch(regnum)
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{
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case M68K_REG_D0: REG_D[0] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_D1: REG_D[1] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_D2: REG_D[2] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_D3: REG_D[3] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_D4: REG_D[4] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_D5: REG_D[5] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_D6: REG_D[6] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_D7: REG_D[7] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A0: REG_A[0] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A1: REG_A[1] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A2: REG_A[2] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A3: REG_A[3] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A4: REG_A[4] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A5: REG_A[5] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A6: REG_A[6] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_A7: REG_A[7] = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_PC: m68ki_jump(MASK_OUT_ABOVE_32(value)); return;
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case M68K_REG_SR: m68ki_set_sr(value); return;
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case M68K_REG_SP: REG_SP = MASK_OUT_ABOVE_32(value); return;
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case M68K_REG_USP: if(FLAG_S)
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REG_USP = MASK_OUT_ABOVE_32(value);
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else
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REG_SP = MASK_OUT_ABOVE_32(value);
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return;
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case M68K_REG_ISP: if(FLAG_S)
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REG_SP = MASK_OUT_ABOVE_32(value);
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else
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REG_ISP = MASK_OUT_ABOVE_32(value);
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return;
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case M68K_REG_IR: REG_IR = MASK_OUT_ABOVE_16(value); return;
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#if M68K_EMULATE_PREFETCH
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case M68K_REG_PREF_ADDR: CPU_PREF_ADDR = MASK_OUT_ABOVE_32(value); return;
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#endif
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default: return;
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}
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}
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/* Set the callbacks */
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#if M68K_EMULATE_INT_ACK == OPT_ON
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void s68k_set_int_ack_callback(int (*callback)(int int_level))
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{
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CALLBACK_INT_ACK = callback ? callback : default_int_ack_callback;
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}
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#endif
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#if M68K_EMULATE_RESET == OPT_ON
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void s68k_set_reset_instr_callback(void (*callback)(void))
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{
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CALLBACK_RESET_INSTR = callback ? callback : default_reset_instr_callback;
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}
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#endif
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#if M68K_TAS_HAS_CALLBACK == OPT_ON
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void s68k_set_tas_instr_callback(int (*callback)(void))
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{
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CALLBACK_TAS_INSTR = callback ? callback : default_tas_instr_callback;
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}
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#endif
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#if M68K_EMULATE_FC == OPT_ON
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void s68k_set_fc_callback(void (*callback)(unsigned int new_fc))
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{
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CALLBACK_SET_FC = callback ? callback : default_set_fc_callback;
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}
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#endif
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extern void error(char *format, ...);
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extern uint16 v_counter;
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/* update IRQ level according to triggered interrupts */
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void s68k_update_irq(unsigned int mask)
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{
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/* Get IRQ level (6 interrupt lines) */
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mask = irq_level[mask];
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/* Set IRQ level */
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CPU_INT_LEVEL = mask << 8;
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/* Check interrupt mask to process IRQ */
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m68ki_check_interrupts();
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#ifdef LOG_SCD
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error("[%d][%d] IRQ Level = %d(0x%02x) (%x)\n", v_counter, s68k.cycles, CPU_INT_LEVEL>>8,FLAG_INT_MASK,s68k.pc);
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#endif
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}
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void s68k_run(unsigned int cycles)
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{
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/* Make sure we're not stopped */
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if (CPU_STOPPED)
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{
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s68k.cycles = cycles;
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return;
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}
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/* Return point for when we have an address error (TODO: use goto) */
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m68ki_set_address_error_trap() /* auto-disable (see m68kcpu.h) */
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/* Save end cycles count for when CPU is stopped */
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s68k.cycle_end = cycles;
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while (s68k.cycles < cycles)
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{
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/* Set tracing accodring to T1. */
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m68ki_trace_t1() /* auto-disable (see m68kcpu.h) */
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/* Set the address space for reads */
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m68ki_use_data_space() /* auto-disable (see m68kcpu.h) */
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/* Decode next instruction */
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REG_IR = m68ki_read_imm_16();
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/* Execute instruction */
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m68ki_instruction_jump_table[REG_IR](); /* TODO: use labels table with goto */
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USE_CYCLES(CYC_INSTRUCTION[REG_IR]); /* TODO: move into instruction handlers */
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/* Trace m68k_exception, if necessary */
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m68ki_exception_if_trace(); /* auto-disable (see m68kcpu.h) */
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}
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}
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void s68k_init(void)
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{
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#ifdef BUILD_TABLES
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static uint emulation_initialized = 0;
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/* The first call to this function initializes the opcode handler jump table */
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if(!emulation_initialized)
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{
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m68ki_build_opcode_table();
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emulation_initialized = 1;
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}
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#endif
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#if M68K_EMULATE_INT_ACK == OPT_ON
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s68k_set_int_ack_callback(NULL);
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#endif
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#if M68K_EMULATE_RESET == OPT_ON
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s68k_set_reset_instr_callback(NULL);
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#endif
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#if M68K_TAS_HAS_CALLBACK == OPT_ON
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s68k_set_tas_instr_callback(NULL);
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#endif
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#if M68K_EMULATE_FC == OPT_ON
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s68k_set_fc_callback(NULL);
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#endif
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}
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/* Pulse the RESET line on the CPU */
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void s68k_pulse_reset(void)
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{
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/* Clear all stop levels */
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CPU_STOPPED = 0;
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#if M68K_EMULATE_ADDRESS_ERROR
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CPU_RUN_MODE = RUN_MODE_BERR_AERR_RESET;
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#endif
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/* Turn off tracing */
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FLAG_T1 = 0;
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m68ki_clear_trace()
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/* Interrupt mask to level 7 */
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FLAG_INT_MASK = 0x0700;
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CPU_INT_LEVEL = 0;
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irq_latency = 0;
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/* Go to supervisor mode */
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m68ki_set_s_flag(SFLAG_SET);
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/* Invalidate the prefetch queue */
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#if M68K_EMULATE_PREFETCH
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/* Set to arbitrary number since our first fetch is from 0 */
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CPU_PREF_ADDR = 0x1000;
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#endif /* M68K_EMULATE_PREFETCH */
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/* Read the initial stack pointer and program counter */
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m68ki_jump(0);
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REG_SP = m68ki_read_imm_32();
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REG_PC = m68ki_read_imm_32();
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m68ki_jump(REG_PC);
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#if M68K_EMULATE_ADDRESS_ERROR
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CPU_RUN_MODE = RUN_MODE_NORMAL;
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#endif
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USE_CYCLES(CYC_EXCEPTION[EXCEPTION_RESET]);
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}
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void s68k_pulse_halt(void)
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{
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/* Pulse the HALT line on the CPU */
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CPU_STOPPED |= STOP_LEVEL_HALT;
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}
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void s68k_clear_halt()
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{
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/* Clear the HALT line on the CPU */
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CPU_STOPPED &= ~STOP_LEVEL_HALT;
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}
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/* ======================================================================== */
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/* ============================== END OF FILE ============================= */
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/* ======================================================================== */
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