famiyirl: add ROL_ab

Signed-off-by: Matthias Gatto <[email protected]>
cosmo-ray · May 1, 2024 · 8f5e0cb · 8f5e0cb
1 parent d324c8d
commit 8f5e0cb
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diff --git a/modules/famiyirl/init.c b/modules/famiyirl/init.c
@@ -258,6 +258,21 @@ static int process_inst(void)
 		cpu.cycle_cnt += 2;
 	}
 	break;
+	case ROL_ab:
+	{
+		int addr = get_mem(++cpu.pc);
+
+		addr |= get_mem(++cpu.pc) << 8;
+		int val = get_mem(addr);
+		char new_c = val & 0x1;
+		val = (val << 1) | cpu.flag & 0x1;
+		set_mem(addr, val);
+		SET_CARY(new_c);
+		SET_NEGATIVE(!!(0x80 & val));
+		SET_ZERO(!val);
+		cpu.cycle_cnt += 6;
+	}
+	break;
 	case EOR_IM:
 	  {
 	    unsigned char addr = get_mem(++cpu.pc);

diff --git a/modules/famiyirl/opcode.h b/modules/famiyirl/opcode.h
@@ -9,6 +9,7 @@
   OPCODE(JSR, 0x20)
   OPCODE(AND_xindir_zp, 0x21) //and (with accumulator)
   OPCODE(ROL_a, 0x2a) //rotate left
+  OPCODE(ROL_ab, 0x2e) //rotate left
   OPCODE(PLP, 0x28) //pull processor status (SR)
   OPCODE(AND_im, 0x29) //and (with accumulator)
   OPCODE(BMI, 0x30) //branch on minus (negative set)