1 files changed, 880 insertions, 0 deletions

diff --git a/apps/plugins/rockboy/cpu.c b/apps/plugins/rockboy/cpu.c
new file mode 100644
index 0000000000..44a870a6eb
--- /dev/null
+++ b/apps/plugins/rockboy/cpu.c
@@ -0,0 +1,880 @@
+
+
+
+#include "rockmacros.h"
+#include "defs.h"
+#include "regs.h"
+#include "hw.h"
+#include "cpu.h"
+#include "lcdc.h"
+#include "mem.h"
+#include "fastmem.h"
+#include "cpuregs.h"
+#include "cpucore.h"
+
+#ifdef USE_ASM
+#include "asm.h"
+#endif
+
+
+struct cpu cpu;
+
+
+
+
+#define ZFLAG(n) ( (n) ? 0 : FZ )
+
+
+#define PUSH(w) ( (SP -= 2), (writew(xSP, (w))) )
+#define POP(w) ( ((w) = readw(xSP)), (SP += 2) )
+
+
+#define FETCH_OLD ( mbc.rmap[PC>>12] \
+? mbc.rmap[PC>>12][PC++] \
+: mem_read(PC++) )
+
+#define FETCH (readb(PC++))
+
+
+#define INC(r) { ((r)++); \
+F = (F & (FL|FC)) | incflag_table[(r)]; }
+
+#define DEC(r) { ((r)--); \
+F = (F & (FL|FC)) | decflag_table[(r)]; }
+
+#define INCW(r) ( (r)++ )
+
+#define DECW(r) ( (r)-- )
+
+#define ADD(n) { \
+W(acc) = (un16)A + (un16)(n); \
+F = (ZFLAG(LB(acc))) \
+| (FH & ((A ^ (n) ^ LB(acc)) << 1)) \
+| (HB(acc) << 4); \
+A = LB(acc); }
+
+#define ADC(n) { \
+W(acc) = (un16)A + (un16)(n) + (un16)((F&FC)>>4); \
+F = (ZFLAG(LB(acc))) \
+| (FH & ((A ^ (n) ^ LB(acc)) << 1)) \
+| (HB(acc) << 4); \
+A = LB(acc); }
+
+#define ADDW(n) { \
+DW(acc) = (un32)HL + (un32)(n); \
+F = (F & (FZ)) \
+| (FH & ((H ^ ((n)>>8) ^ HB(acc)) << 1)) \
+| (acc.b[HI][LO] << 4); \
+HL = W(acc); }
+
+#define ADDSP(n) { \
+DW(acc) = (un32)SP + (un32)(n8)(n); \
+F = (FH & (((SP>>8) ^ ((n)>>8) ^ HB(acc)) << 1)) \
+| (acc.b[HI][LO] << 4); \
+SP = W(acc); }
+
+#define LDHLSP(n) { \
+DW(acc) = (un32)SP + (un32)(n8)(n); \
+F = (FH & (((SP>>8) ^ ((n)>>8) ^ HB(acc)) << 1)) \
+| (acc.b[HI][LO] << 4); \
+HL = W(acc); }
+
+#define CP(n) { \
+W(acc) = (un16)A - (un16)(n); \
+F = FN \
+| (ZFLAG(LB(acc))) \
+| (FH & ((A ^ (n) ^ LB(acc)) << 1)) \
+| ((un8)(-(n8)HB(acc)) << 4); }
+
+#define SUB(n) { CP((n)); A = LB(acc); }
+
+#define SBC(n) { \
+W(acc) = (un16)A - (un16)(n) - (un16)((F&FC)>>4); \
+F = FN \
+| (ZFLAG((n8)LB(acc))) \
+| (FH & ((A ^ (n) ^ LB(acc)) << 1)) \
+| ((un8)(-(n8)HB(acc)) << 4); \
+A = LB(acc); }
+
+#define AND(n) { A &= (n); \
+F = ZFLAG(A) | FH; }
+
+#define XOR(n) { A ^= (n); \
+F = ZFLAG(A); }
+
+#define OR(n) { A |= (n); \
+F = ZFLAG(A); }
+
+#define RLCA(r) { (r) = ((r)>>7) | ((r)<<1); \
+F = (((r)&0x01)<<4); }
+
+#define RRCA(r) { (r) = ((r)<<7) | ((r)>>1); \
+F = (((r)&0x80)>>3); }
+
+#define RLA(r) { \
+LB(acc) = (((r)&0x80)>>3); \
+(r) = ((r)<<1) | ((F&FC)>>4); \
+F = LB(acc); }
+
+#define RRA(r) { \
+LB(acc) = (((r)&0x01)<<4); \
+(r) = ((r)>>1) | ((F&FC)<<3); \
+F = LB(acc); }
+
+#define RLC(r) { RLCA(r); F |= ZFLAG(r); }
+#define RRC(r) { RRCA(r); F |= ZFLAG(r); }
+#define RL(r) { RLA(r); F |= ZFLAG(r); }
+#define RR(r) { RRA(r); F |= ZFLAG(r); }
+
+#define SLA(r) { \
+LB(acc) = (((r)&0x80)>>3); \
+(r) <<= 1; \
+F = ZFLAG((r)) | LB(acc); }
+
+#define SRA(r) { \
+LB(acc) = (((r)&0x01)<<4); \
+(r) = (un8)(((n8)(r))>>1); \
+F = ZFLAG((r)) | LB(acc); }
+
+#define SRL(r) { \
+LB(acc) = (((r)&0x01)<<4); \
+(r) >>= 1; \
+F = ZFLAG((r)) | LB(acc); }
+
+#define CPL(r) { \
+(r) = ~(r); \
+F |= (FH|FN); }
+
+#define SCF { F = (F & (FZ)) | FC; }
+
+#define CCF { F = (F & (FZ|FC)) ^ FC; }
+
+#define DAA { \
+A += (LB(acc) = daa_table[((((int)F)&0x70)<<4) | A]); \
+F = (F & (FN)) | ZFLAG(A) | daa_carry_table[LB(acc)>>2]; }
+
+#define SWAP(r) { \
+(r) = swap_table[(r)]; \
+F = ZFLAG((r)); }
+
+#define BIT(n,r) { F = (F & FC) | ZFLAG(((r) & (1 << (n)))) | FH; }
+#define RES(n,r) { (r) &= ~(1 << (n)); }
+#define SET(n,r) { (r) |= (1 << (n)); }
+
+#define CB_REG_CASES(r, n) \
+case 0x00|(n): RLC(r); break; \
+case 0x08|(n): RRC(r); break; \
+case 0x10|(n): RL(r); break; \
+case 0x18|(n): RR(r); break; \
+case 0x20|(n): SLA(r); break; \
+case 0x28|(n): SRA(r); break; \
+case 0x30|(n): SWAP(r); break; \
+case 0x38|(n): SRL(r); break; \
+case 0x40|(n): BIT(0, r); break; \
+case 0x48|(n): BIT(1, r); break; \
+case 0x50|(n): BIT(2, r); break; \
+case 0x58|(n): BIT(3, r); break; \
+case 0x60|(n): BIT(4, r); break; \
+case 0x68|(n): BIT(5, r); break; \
+case 0x70|(n): BIT(6, r); break; \
+case 0x78|(n): BIT(7, r); break; \
+case 0x80|(n): RES(0, r); break; \
+case 0x88|(n): RES(1, r); break; \
+case 0x90|(n): RES(2, r); break; \
+case 0x98|(n): RES(3, r); break; \
+case 0xA0|(n): RES(4, r); break; \
+case 0xA8|(n): RES(5, r); break; \
+case 0xB0|(n): RES(6, r); break; \
+case 0xB8|(n): RES(7, r); break; \
+case 0xC0|(n): SET(0, r); break; \
+case 0xC8|(n): SET(1, r); break; \
+case 0xD0|(n): SET(2, r); break; \
+case 0xD8|(n): SET(3, r); break; \
+case 0xE0|(n): SET(4, r); break; \
+case 0xE8|(n): SET(5, r); break; \
+case 0xF0|(n): SET(6, r); break; \
+case 0xF8|(n): SET(7, r); break;
+
+
+#define ALU_CASES(base, imm, op, label) \
+case (imm): b = FETCH; goto label; \
+case (base): b = B; goto label; \
+case (base)+1: b = C; goto label; \
+case (base)+2: b = D; goto label; \
+case (base)+3: b = E; goto label; \
+case (base)+4: b = H; goto label; \
+case (base)+5: b = L; goto label; \
+case (base)+6: b = readb(HL); goto label; \
+case (base)+7: b = A; \
+label: op(b); break;
+
+
+
+
+
+
+
+
+#define JR ( PC += 1+(n8)readb(PC) )
+#define JP ( PC = readw(PC) )
+
+#define CALL ( PUSH(PC+2), JP )
+
+#define NOJR ( clen--, PC++ )
+#define NOJP ( clen--, PC+=2 )
+#define NOCALL ( clen-=3, PC+=2 )
+#define NORET ( clen-=3 )
+
+#define RST(n) { PUSH(PC); PC = (n); }
+
+#define RET ( POP(PC) )
+
+#define EI ( IMA = 1 )
+#define DI ( cpu.halt = IMA = IME = 0 )
+
+
+
+#define PRE_INT ( DI, PUSH(PC) )
+#define THROW_INT(n) ( (IF &= ~(1<<(n))), (PC = 0x40+((n)<<3)) )
+
+
+
+
+void cpu_reset(void)
+{
+        cpu.speed = 0;
+        cpu.halt = 0;
+        cpu.div = 0;
+        cpu.tim = 0;
+        cpu.lcdc = 40;
+
+        IME = 0;
+        IMA = 0;
+        
+        PC = 0x0100;
+        SP = 0xFFFE;
+        AF = 0x01B0;
+        BC = 0x0013;
+        DE = 0x00D8;
+        HL = 0x014D;
+
+        if (hw.cgb) A = 0x11;
+        if (hw.gba) B = 0x01;
+}
+
+
+void div_advance(int cnt)
+{
+        cpu.div += (cnt<<1);
+        if (cpu.div >= 256)
+        {
+                R_DIV += (cpu.div >> 8);
+                cpu.div &= 0xff;
+        }
+}
+
+void timer_advance(int cnt)
+{
+        int unit, tima;
+        
+        if (!(R_TAC & 0x04)) return;
+
+        unit = ((-R_TAC) & 3) << 1;
+        cpu.tim += (cnt<<unit);
+
+        if (cpu.tim >= 512)
+        {
+                tima = R_TIMA + (cpu.tim >> 9);
+                cpu.tim &= 0x1ff;
+                if (tima >= 256)
+                {
+                        hw_interrupt(IF_TIMER, IF_TIMER);
+                        hw_interrupt(0, IF_TIMER);
+                }
+                while (tima >= 256)
+                        tima = tima - 256 + R_TMA;
+                R_TIMA = tima;
+        }
+}
+
+void lcdc_advance(int cnt)
+{
+        cpu.lcdc -= cnt;
+        if (cpu.lcdc <= 0) lcdc_trans();
+}
+
+void sound_advance(int cnt)
+{
+        cpu.snd += cnt;
+}
+
+void cpu_timers(int cnt)
+{
+        div_advance(cnt << cpu.speed);
+        timer_advance(cnt << cpu.speed);
+        lcdc_advance(cnt);
+        sound_advance(cnt);
+}
+
+int cpu_idle(int max)
+{
+        int cnt, unit;
+
+        if (!(cpu.halt && IME)) return 0;
+        if (R_IF & R_IE)
+        {
+                cpu.halt = 0;
+                return 0;
+        }
+
+        /* Make sure we don't miss lcdc status events! */
+        if ((R_IE & (IF_VBLANK | IF_STAT)) && (max > cpu.lcdc))
+                max = cpu.lcdc;
+        
+        /* If timer interrupt cannot happen, this is very simple! */
+        if (!((R_IE & IF_TIMER) && (R_TAC & 0x04)))
+        {
+                cpu_timers(max);
+                return max;
+        }
+
+        /* Figure out when the next timer interrupt will happen */
+        unit = ((-R_TAC) & 3) << 1;
+        cnt = (511 - cpu.tim + (1<<unit)) >> unit;
+        cnt += (255 - R_TIMA) << (9 - unit);
+
+        if (max < cnt)
+                cnt = max;
+        
+        cpu_timers(cnt);
+        return cnt;
+}
+
+#ifndef ASM_CPU_EMULATE
+
+extern int debug_trace;
+
+int cpu_emulate(int cycles)
+{
+        int i;
+        byte op, cbop;
+        int clen;
+        static union reg acc;
+        static byte b;
+        static word w;
+
+        i = cycles;
+next:
+        if ((clen = cpu_idle(i)))
+        {
+                i -= clen;
+                if (i > 0) goto next;
+                return cycles-i;
+        }
+
+        if (IME && (IF & IE))
+        {
+                PRE_INT;
+                switch ((byte)(IF & IE))
+                {
+                case 0x01: case 0x03: case 0x05: case 0x07:
+                case 0x09: case 0x0B: case 0x0D: case 0x0F:
+                case 0x11: case 0x13: case 0x15: case 0x17:
+                case 0x19: case 0x1B: case 0x1D: case 0x1F:
+                        THROW_INT(0); break;
+                case 0x02: case 0x06: case 0x0A: case 0x0E:
+                case 0x12: case 0x16: case 0x1A: case 0x1E:
+                        THROW_INT(1); break;
+                case 0x04: case 0x0C: case 0x14: case 0x1C:
+                        THROW_INT(2); break;
+                case 0x08: case 0x18:
+                        THROW_INT(3); break;
+                case 0x10:
+                        THROW_INT(4); break;
+                }
+        }
+        IME = IMA;
+        
+//      if (debug_trace) debug_disassemble(PC, 1);
+                                
+        op = FETCH;
+        clen = cycles_table[op];
+
+        switch(op)
+        {
+        case 0x00: /* NOP */
+        case 0x40: /* LD B,B */
+        case 0x49: /* LD C,C */
+        case 0x52: /* LD D,D */
+        case 0x5B: /* LD E,E */
+        case 0x64: /* LD H,H */
+        case 0x6D: /* LD L,L */
+        case 0x7F: /* LD A,A */
+                break;
+                        
+        case 0x41: /* LD B,C */
+                B = C; break;
+        case 0x42: /* LD B,D */
+                B = D; break;
+        case 0x43: /* LD B,E */
+                B = E; break;
+        case 0x44: /* LD B,H */
+                B = H; break;
+        case 0x45: /* LD B,L */
+                B = L; break;
+        case 0x46: /* LD B,(HL) */
+                B = readb(xHL); break;
+        case 0x47: /* LD B,A */
+                B = A; break;
+
+        case 0x48: /* LD C,B */
+                C = B; break;
+        case 0x4A: /* LD C,D */
+                C = D; break;
+        case 0x4B: /* LD C,E */
+                C = E; break;
+        case 0x4C: /* LD C,H */
+                C = H; break;
+        case 0x4D: /* LD C,L */
+                C = L; break;
+        case 0x4E: /* LD C,(HL) */
+                C = readb(xHL); break;
+        case 0x4F: /* LD C,A */
+                C = A; break;
+
+        case 0x50: /* LD D,B */
+                D = B; break;
+        case 0x51: /* LD D,C */
+                D = C; break;
+        case 0x53: /* LD D,E */
+                D = E; break;
+        case 0x54: /* LD D,H */
+                D = H; break;
+        case 0x55: /* LD D,L */
+                D = L; break;
+        case 0x56: /* LD D,(HL) */
+                D = readb(xHL); break;
+        case 0x57: /* LD D,A */
+                D = A; break;
+
+        case 0x58: /* LD E,B */
+                E = B; break;
+        case 0x59: /* LD E,C */
+                E = C; break;
+        case 0x5A: /* LD E,D */
+                E = D; break;
+        case 0x5C: /* LD E,H */
+                E = H; break;
+        case 0x5D: /* LD E,L */
+                E = L; break;
+        case 0x5E: /* LD E,(HL) */
+                E = readb(xHL); break;
+        case 0x5F: /* LD E,A */
+                E = A; break;
+
+        case 0x60: /* LD H,B */
+                H = B; break;
+        case 0x61: /* LD H,C */
+                H = C; break;
+        case 0x62: /* LD H,D */
+                H = D; break;
+        case 0x63: /* LD H,E */
+                H = E; break;
+        case 0x65: /* LD H,L */
+                H = L; break;
+        case 0x66: /* LD H,(HL) */
+                H = readb(xHL); break;
+        case 0x67: /* LD H,A */
+                H = A; break;
+                        
+        case 0x68: /* LD L,B */
+                L = B; break;
+        case 0x69: /* LD L,C */
+                L = C; break;
+        case 0x6A: /* LD L,D */
+                L = D; break;
+        case 0x6B: /* LD L,E */
+                L = E; break;
+        case 0x6C: /* LD L,H */
+                L = H; break;
+        case 0x6E: /* LD L,(HL) */
+                L = readb(xHL); break;
+        case 0x6F: /* LD L,A */
+                L = A; break;
+                        
+        case 0x70: /* LD (HL),B */
+                b = B; goto __LD_HL;
+        case 0x71: /* LD (HL),C */
+                b = C; goto __LD_HL;
+        case 0x72: /* LD (HL),D */
+                b = D; goto __LD_HL;
+        case 0x73: /* LD (HL),E */
+                b = E; goto __LD_HL;
+        case 0x74: /* LD (HL),H */
+                b = H; goto __LD_HL;
+        case 0x75: /* LD (HL),L */
+                b = L; goto __LD_HL;
+        case 0x77: /* LD (HL),A */
+                b = A;
+        __LD_HL:
+                writeb(xHL,b);
+                break;
+                        
+        case 0x78: /* LD A,B */
+                A = B; break;
+        case 0x79: /* LD A,C */
+                A = C; break;
+        case 0x7A: /* LD A,D */
+                A = D; break;
+        case 0x7B: /* LD A,E */
+                A = E; break;
+        case 0x7C: /* LD A,H */
+                A = H; break;
+        case 0x7D: /* LD A,L */
+                A = L; break;
+        case 0x7E: /* LD A,(HL) */
+                A = readb(xHL); break;
+
+        case 0x01: /* LD BC,imm */
+                BC = readw(xPC); PC += 2; break;
+        case 0x11: /* LD DE,imm */
+                DE = readw(xPC); PC += 2; break;
+        case 0x21: /* LD HL,imm */
+                HL = readw(xPC); PC += 2; break;
+        case 0x31: /* LD SP,imm */
+                SP = readw(xPC); PC += 2; break;
+
+        case 0x02: /* LD (BC),A */
+                writeb(xBC, A); break;
+        case 0x0A: /* LD A,(BC) */
+                A = readb(xBC); break;
+        case 0x12: /* LD (DE),A */
+                writeb(xDE, A); break;
+        case 0x1A: /* LD A,(DE) */
+                A = readb(xDE); break;
+
+        case 0x22: /* LDI (HL),A */
+                writeb(xHL, A); HL++; break;
+        case 0x2A: /* LDI A,(HL) */
+                A = readb(xHL); HL++; break;
+        case 0x32: /* LDD (HL),A */
+                writeb(xHL, A); HL--; break;
+        case 0x3A: /* LDD A,(HL) */
+                A = readb(xHL); HL--; break;
+
+        case 0x06: /* LD B,imm */
+                B = FETCH; break;
+        case 0x0E: /* LD C,imm */
+                C = FETCH; break;
+        case 0x16: /* LD D,imm */
+                D = FETCH; break;
+        case 0x1E: /* LD E,imm */
+                E = FETCH; break;
+        case 0x26: /* LD H,imm */
+                H = FETCH; break;
+        case 0x2E: /* LD L,imm */
+                L = FETCH; break;
+        case 0x36: /* LD (HL),imm */
+                b = FETCH; writeb(xHL, b); break;
+        case 0x3E: /* LD A,imm */
+                A = FETCH; break;
+
+        case 0x08: /* LD (imm),SP */
+                writew(readw(xPC), SP); PC += 2; break;
+        case 0xEA: /* LD (imm),A */
+                writeb(readw(xPC), A); PC += 2; break;
+
+        case 0xE0: /* LDH (imm),A */
+                writehi(FETCH, A); break;
+        case 0xE2: /* LDH (C),A */
+                writehi(C, A); break;
+        case 0xF0: /* LDH A,(imm) */
+                A = readhi(FETCH); break;
+        case 0xF2: /* LDH A,(C) (undocumented) */
+                A = readhi(C); break;
+                        
+
+        case 0xF8: /* LD HL,SP+imm */
+                b = FETCH; LDHLSP(b); break;
+        case 0xF9: /* LD SP,HL */
+                SP = HL; break;
+        case 0xFA: /* LD A,(imm) */
+                A = readb(readw(xPC)); PC += 2; break;
+
+                ALU_CASES(0x80, 0xC6, ADD, __ADD)
+                ALU_CASES(0x88, 0xCE, ADC, __ADC)
+                ALU_CASES(0x90, 0xD6, SUB, __SUB)
+                ALU_CASES(0x98, 0xDE, SBC, __SBC)
+                ALU_CASES(0xA0, 0xE6, AND, __AND)
+                ALU_CASES(0xA8, 0xEE, XOR, __XOR)
+                ALU_CASES(0xB0, 0xF6, OR, __OR)
+                ALU_CASES(0xB8, 0xFE, CP, __CP)
+
+        case 0x09: /* ADD HL,BC */
+                w = BC; goto __ADDW;
+        case 0x19: /* ADD HL,DE */
+                w = DE; goto __ADDW;
+        case 0x39: /* ADD HL,SP */
+                w = SP; goto __ADDW;
+        case 0x29: /* ADD HL,HL */
+                w = HL;
+        __ADDW:
+                ADDW(w);
+                break;
+
+        case 0x04: /* INC B */
+                INC(B); break;
+        case 0x0C: /* INC C */
+                INC(C); break;
+        case 0x14: /* INC D */
+                INC(D); break;
+        case 0x1C: /* INC E */
+                INC(E); break;
+        case 0x24: /* INC H */
+                INC(H); break;
+        case 0x2C: /* INC L */
+                INC(L); break;
+        case 0x34: /* INC (HL) */
+                b = readb(xHL);
+                INC(b);
+                writeb(xHL, b);
+                break;
+        case 0x3C: /* INC A */
+                INC(A); break;
+                        
+        case 0x03: /* INC BC */
+                INCW(BC); break;
+        case 0x13: /* INC DE */
+                INCW(DE); break;
+        case 0x23: /* INC HL */
+                INCW(HL); break;
+        case 0x33: /* INC SP */
+                INCW(SP); break;
+                        
+        case 0x05: /* DEC B */
+                DEC(B); break;
+        case 0x0D: /* DEC C */
+                DEC(C); break;
+        case 0x15: /* DEC D */
+                DEC(D); break;
+        case 0x1D: /* DEC E */
+                DEC(E); break;
+        case 0x25: /* DEC H */
+                DEC(H); break;
+        case 0x2D: /* DEC L */
+                DEC(L); break;
+        case 0x35: /* DEC (HL) */
+                b = readb(xHL);
+                DEC(b);
+                writeb(xHL, b);
+                break;
+        case 0x3D: /* DEC A */
+                DEC(A); break;
+
+        case 0x0B: /* DEC BC */
+                DECW(BC); break;
+        case 0x1B: /* DEC DE */
+                DECW(DE); break;
+        case 0x2B: /* DEC HL */
+                DECW(HL); break;
+        case 0x3B: /* DEC SP */
+                DECW(SP); break;
+
+        case 0x07: /* RLCA */
+                RLCA(A); break;
+        case 0x0F: /* RRCA */
+                RRCA(A); break;
+        case 0x17: /* RLA */
+                RLA(A); break;
+        case 0x1F: /* RRA */
+                RRA(A); break;
+
+        case 0x27: /* DAA */
+                DAA; break;
+        case 0x2F: /* CPL */
+                CPL(A); break;
+
+        case 0x18: /* JR */
+        __JR:
+                JR; break;
+        case 0x20: /* JR NZ */
+                if (!(F&FZ)) goto __JR; NOJR; break;
+        case 0x28: /* JR Z */
+                if (F&FZ) goto __JR; NOJR; break;
+        case 0x30: /* JR NC */
+                if (!(F&FC)) goto __JR; NOJR; break;
+        case 0x38: /* JR C */
+                if (F&FC) goto __JR; NOJR; break;
+
+        case 0xC3: /* JP */
+        __JP:
+                JP; break;
+        case 0xC2: /* JP NZ */
+                if (!(F&FZ)) goto __JP; NOJP; break;
+        case 0xCA: /* JP Z */
+                if (F&FZ) goto __JP; NOJP; break;
+        case 0xD2: /* JP NC */
+                if (!(F&FC)) goto __JP; NOJP; break;
+        case 0xDA: /* JP C */
+                if (F&FC) goto __JP; NOJP; break;
+        case 0xE9: /* JP HL */
+                PC = HL; break;
+
+        case 0xC9: /* RET */
+        __RET:
+                RET; break;
+        case 0xC0: /* RET NZ */
+                if (!(F&FZ)) goto __RET; NORET; break;
+        case 0xC8: /* RET Z */
+                if (F&FZ) goto __RET; NORET; break;
+        case 0xD0: /* RET NC */
+                if (!(F&FC)) goto __RET; NORET; break;
+        case 0xD8: /* RET C */
+                if (F&FC) goto __RET; NORET; break;
+        case 0xD9: /* RETI */
+                IME = IMA = 1; goto __RET;
+
+        case 0xCD: /* CALL */
+        __CALL:
+                CALL; break;
+        case 0xC4: /* CALL NZ */
+                if (!(F&FZ)) goto __CALL; NOCALL; break;
+        case 0xCC: /* CALL Z */
+                if (F&FZ) goto __CALL; NOCALL; break;
+        case 0xD4: /* CALL NC */
+                if (!(F&FC)) goto __CALL; NOCALL; break;
+        case 0xDC: /* CALL C */
+                if (F&FC) goto __CALL; NOCALL; break;
+
+        case 0xC7: /* RST 0 */
+                b = 0x00; goto __RST;
+        case 0xCF: /* RST 8 */
+                b = 0x08; goto __RST;
+        case 0xD7: /* RST 10 */
+                b = 0x10; goto __RST;
+        case 0xDF: /* RST 18 */
+                b = 0x18; goto __RST;
+        case 0xE7: /* RST 20 */
+                b = 0x20; goto __RST;
+        case 0xEF: /* RST 28 */
+                b = 0x28; goto __RST;
+        case 0xF7: /* RST 30 */
+                b = 0x30; goto __RST;
+        case 0xFF: /* RST 38 */
+                b = 0x38;
+        __RST:
+                RST(b); break;
+                        
+        case 0xC1: /* POP BC */
+                POP(BC); break;
+        case 0xC5: /* PUSH BC */
+                PUSH(BC); break;
+        case 0xD1: /* POP DE */
+                POP(DE); break;
+        case 0xD5: /* PUSH DE */
+                PUSH(DE); break;
+        case 0xE1: /* POP HL */
+                POP(HL); break;
+        case 0xE5: /* PUSH HL */
+                PUSH(HL); break;
+        case 0xF1: /* POP AF */
+                POP(AF); break;
+        case 0xF5: /* PUSH AF */
+                PUSH(AF); break;
+
+        case 0xE8: /* ADD SP,imm */
+                b = FETCH; ADDSP(b); break;
+
+        case 0xF3: /* DI */
+                DI; break;
+        case 0xFB: /* EI */
+                EI; break;
+
+        case 0x37: /* SCF */
+                SCF; break;
+        case 0x3F: /* CCF */
+                CCF; break;
+
+        case 0x10: /* STOP */
+                PC++;
+                if (R_KEY1 & 1)
+                {
+                        cpu.speed = cpu.speed ^ 1;
+                        R_KEY1 = (R_KEY1 & 0x7E) | (cpu.speed << 7);
+                        break;
+                }
+                /* NOTE - we do not implement dmg STOP whatsoever */
+                break;
+                        
+        case 0x76: /* HALT */
+                cpu.halt = 1;
+                break;
+
+        case 0xCB: /* CB prefix */
+                cbop = FETCH;
+                clen = cb_cycles_table[cbop];
+                switch (cbop)
+                {
+                        CB_REG_CASES(B, 0);
+                        CB_REG_CASES(C, 1);
+                        CB_REG_CASES(D, 2);
+                        CB_REG_CASES(E, 3);
+                        CB_REG_CASES(H, 4);
+                        CB_REG_CASES(L, 5);
+                        CB_REG_CASES(A, 7);
+                default:
+                        b = readb(xHL);
+                        switch(cbop)
+                        {
+                                CB_REG_CASES(b, 6);
+                        }
+                        if ((cbop & 0xC0) != 0x40) /* exclude BIT */
+                                writeb(xHL, b);
+                        break;
+                }
+                break;
+                        
+        default:
+                die(
+                        "invalid opcode 0x%02X at address 0x%04X, rombank = %d\n",
+                        op, (PC-1) & 0xffff, mbc.rombank);
+                break;
+        }
+
+        clen <<= 1;
+        div_advance(clen);
+        timer_advance(clen);
+        clen >>= cpu.speed;
+        lcdc_advance(clen);
+        sound_advance(clen);
+
+        i -= clen;
+        if (i > 0) goto next;
+        return cycles-i;
+}
+
+#endif /* ASM_CPU_EMULATE */
+
+
+#ifndef ASM_CPU_STEP
+
+int cpu_step(int max)
+{
+        int cnt;
+        if ((cnt = cpu_idle(max))) return cnt;
+        return cpu_emulate(1);
+}
+
+#endif /* ASM_CPU_STEP */
+
+
+
+
+
+
+
+
+
+
+
+