From 4e3d071f23ad853254d0a8048f99105b23b92136 Mon Sep 17 00:00:00 2001
From: cth103 <cth103.b@gmail.com>
Date: Wed, 6 Jun 2018 21:28:01 +0000
Subject: [PATCH] add opcodes

---
 arm/cpu.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 153 insertions(+), 1 deletion(-)

diff --git a/arm/cpu.c b/arm/cpu.c
index ec27c29..794bb2b 100644
--- a/arm/cpu.c
+++ b/arm/cpu.c
@@ -11,6 +11,7 @@ uint64_t *MEMORY; //Memory
 
 void interpret(uint64_t opcode) {
 	switch(opcode) { //ADC (Add with Carry)
+	/* Add/subtract (with carry).  */
 		case 0x1a000000:
 			MEMORY[pc+1] = MEMORY[pc+2] + MEMORY[pc+3] + C;
 			//dest = op_1 + op_2 + Carry
@@ -71,7 +72,7 @@ void interpret(uint64_t opcode) {
 			//dest = op_1 - op_2 - NOT(Carry)
 			pc = pc + 1;
 			break;
-		case 0x7a000000: //SBC (Subtract with Carry With Status)
+		case 0x7a000000: //SBCS (Subtract with Carry With Status)
 			MEMORY[pc+1] = MEMORY[pc+2] - MEMORY[pc+3] - ~C;
 			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
 				C = 0x00000001;
@@ -91,5 +92,156 @@ void interpret(uint64_t opcode) {
 			//dest = op_1 - op_2 - NOT(Carry)
 			pc = pc + 1;
 			break;
+		case 0x5a0003e0: //NGC (Negate with Carry) (This instruction is an alias of SBC.)
+			MEMORY[pc+1] = MEMORY[pc+2] - MEMORY[pc+3] - ~C;
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] < 0x00000000) { //negative?
+				N = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//dest = op_1 - op_2 - NOT(Carry)
+			pc = pc + 1;
+			break;
+		case 0x7a0003e0: //NGCS (Negate with Carry With Status) (This instruction is an alias of SBCS.)
+			MEMORY[pc+1] = MEMORY[pc+2] - MEMORY[pc+3] - ~C;
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] < 0x00000000) { //negative?
+				N = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//dest = op_1 - op_2 - NOT(Carry)
+			pc = pc + 1;
+			break;
+		/* Add/subtract (extended register).  */
+		case 0x0b200000: //ADD (adds...)
+			MEMORY[pc+1] = MEMORY[pc+2] + MEMORY[pc+3];
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] < 0x00000000) { //negative?
+				N = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//dest = op_1 + op_2
+			pc = pc + 1;
+			break;
+		case 0x2b200000: //ADDS (adds With Status)
+			MEMORY[pc+1] = MEMORY[pc+2] + MEMORY[pc+3];
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] < 0x00000000) { //negative?
+				N = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//dest = op_1 + op_2
+			pc = pc + 1;
+			break;
+		case 0x2b20001f: //CMN (Compare Negative)
+			N = MEMORY[pc+2] - ~MEMORY[pc+3];
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//<flags> = op_1 - (NOT op_2)  ; result is not stored, only flags updated
+			pc = pc + 1;
+			break;
+		case 0x4b200000: //SUB (substracts)
+			MEMORY[pc+1] = MEMORY[pc+2] - MEMORY[pc+3];
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] < 0x00000000) { //negative?
+				N = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//dest = op_1 - op_2
+			pc = pc + 1;
+			break;
+		case 0x6b200000: //SUBS (substracts with status)
+			MEMORY[pc+1] = MEMORY[pc+2] - MEMORY[pc+3];
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] < 0x00000000) { //negative?
+				N = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//dest = op_1 - op_2
+			pc = pc + 1;
+			break;
+		case 0x6b20001f: //CMP (COMPARE)
+			N = MEMORY[pc+2] - MEMORY[pc+3];
+			if (MEMORY[pc+1] => 0xffffffff) { //overflow (unsigned signed)?
+				C = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			if (MEMORY[pc+1] = 0x00000000) { //zero?
+				Z = 0x00000001;
+				pc = pc + 1;
+				break;
+			}
+			//<flags> = op_1 - op_2  ; result is not stored, only flags updated
+			pc = pc + 1;
+			break;
 	}
 }
\ No newline at end of file
-- 
2.11.4.GIT