From e16a879527302502638b8185cb92c3fb9a029d4e Mon Sep 17 00:00:00 2001
From: g1n <g1n@ttm.sh>
Date: Thu, 14 Oct 2021 14:18:37 +0300
Subject: [PATCH] Add 6502 TXA instruction

---
 src/6502.c   |  5 +++++
 src/6502.h   | 14 ++++++++++++++
 src/Makefile |  2 +-
 src/main.c   |  6 ++++--
 4 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/6502.c b/src/6502.c
index eff29a2..c8b1d0f 100644
--- a/src/6502.c
+++ b/src/6502.c
@@ -1,6 +1,10 @@
 #include <stdio.h>
 #include "6502.h"
 
+void txa(FILE *outfile) {
+  fwrite(TXA, 1, 1, outfile);
+}
+
 void inx(FILE *outfile) {
   fwrite(INX, 1, 1, outfile);
 }
@@ -12,3 +16,4 @@ void iny(FILE *outfile) {
 void nop(FILE *outfile) {
   fwrite(NOP, 1, 1, outfile);
 }
+
diff --git a/src/6502.h b/src/6502.h
index edf1f67..1ef1b21 100644
--- a/src/6502.h
+++ b/src/6502.h
@@ -1,9 +1,23 @@
+#ifndef _6502_H
+#define _6502_H
+
+#define TAX "\xAA"
+#define TAY "\xA8"
+#define TSX "\xBA"
+#define TXA "\x8A"
+#define TXS "\x9A"
+#define TYA "\x98"
+
 #define INX "\xE8"
 #define INY "\xC8"
 
 #define NOP "\xEA"
 
+void txa(FILE *outfile);
+
 void inx(FILE *outfile);
 void iny(FILE *outfile);
 
 void nop(FILE *outfile);
+
+#endif
diff --git a/src/Makefile b/src/Makefile
index d518cee..d342a24 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -13,6 +13,6 @@ all: main
 main: 
 	$(CC) $(CFLAGS) $(SRCFILES) -o $(OBJFILES)
 test: 
-	./gasm ../tests/test.asm ../tests/test.bin
+	./gasm ../tests/test.asm -o ../tests/test.bin
 	xxd ../tests/test.bin
 
diff --git a/src/main.c b/src/main.c
index 965235a..f4d2ce7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -39,9 +39,11 @@ void parser(char lexed_buf[512][128][128], FILE *outfile) { // outfile is needed
 			  inx(outfile);
 			} else if (!strcmp(lexed_buf[i][j], "INY")) {
 			  iny(outfile);
+			} else if (!strcmp(lexed_buf[i][j], "TXA")) {
+			  txa(outfile);
 			} else {
-				printf("Unrecognized command: %s\n", lexed_buf[i][j]);
-				break;
+			  printf("Unrecognized command: %s\n", lexed_buf[i][j]);
+			  break;
 			}
 		}
 	}