From 262a211da9731c2c750bb73b5e1e62466eed002e Mon Sep 17 00:00:00 2001
From: d0p1 <contact@d0p1.eu>
Date: Thu, 29 Feb 2024 13:01:58 +0100
Subject: [PATCH] Basic cli handling

---
 configure.ac       |  11 +-
 disas/main.c       | 407 ++++++++++++++++++++++++++-------------------
 lib/op.c           |  42 ++---
 lib/op.h           |   1 +
 vm/Makefile.am     |  22 +--
 vm/ata/Makefrag.am |  18 +-
 vm/ata/ethernet.c  |  28 ++--
 vm/ata/rtc.c       |  90 +++++-----
 vm/bus.h           |  16 ++
 vm/cpu.c           |  23 +++
 vm/cpu.h           |  16 ++
 vm/main.c          |  83 +++++++--
 vm/net/tap-linux.c |  32 ++++
 vm/vm.h            |  17 ++
 14 files changed, 514 insertions(+), 292 deletions(-)
 create mode 100644 vm/bus.h
 create mode 100644 vm/cpu.c
 create mode 100644 vm/cpu.h
 create mode 100644 vm/net/tap-linux.c
 create mode 100644 vm/vm.h

diff --git a/configure.ac b/configure.ac
index 392daac..a7b556e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,7 @@
-AC_INIT([65oo2], [1.0])
+AC_INIT([65∞2], [1.0],
+		[https://git.cute.engineering/d0p1/65oo2/issues],
+		[65oo2],
+		[https://git.cute.engineering/d0p1/65oo2])
 
 AC_CANONICAL_HOST
 
@@ -25,6 +28,9 @@ AM_PROG_CC_C_O
 PKG_PROG_PKG_CONFIG
 AC_CHECK_TOOLS(WINDRES, [windres], :)
 
+PKG_CHECK_MODULES([SDL2], [sdl2])
+SDL2_LIBS=${SDL2_LIBS/-mwindows/}
+
 AC_ARG_ENABLE([ata-vga],
 	[AS_HELP_STRING([--enable-ata-vga], [enable VGA (default=yes)])],
 	[WANT_ATA_VGA=$enableval], [WANT_ATA_VGA=yes])
@@ -40,13 +46,12 @@ AC_ARG_ENABLE(jit,
 	[WANT_JIT=$enableval], [WANT_JIT=no])
 
 AC_CHECK_INCLUDES_DEFAULT
+AC_CHECK_HEADERS([libgen.h])
 AC_C_CONST
 
 AM_CONDITIONAL([USE_ATA_VGA], test "$WANT_ATA_VGA" = "yes")
 if test "$WANT_ATA_VGA" = "yes"; then
    AC_DEFINE([ATA_VGA], [1], [Enable VGA device])
-   PKG_CHECK_MODULES([SDL2], [sdl2])
-
 fi
 
 AM_CONDITIONAL([USE_ATA_ETHERNET], test "$WANT_ATA_ETHERNET" = "yes")
diff --git a/disas/main.c b/disas/main.c
index 89314e3..2c21a9a 100644
--- a/disas/main.c
+++ b/disas/main.c
@@ -1,11 +1,15 @@
+#include "config.h"
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdarg.h>
+#ifdef HAVE_LIBGEN_H
+# include <libgen.h>
+#endif /* HAVE_LIBGEN_H */
 #include "lib/op.h"
 
 #define OP_ADDR_MODE (OP_ADDR_IMPL | OP_ADDR_REL | OP_ADDR_IND	\
-  | OP_ADDR_IMM | OP_ADDR_ABS)
+					  | OP_ADDR_IMM | OP_ADDR_ABS)
 
 char *prg_name;
 FILE *input;
@@ -14,261 +18,318 @@ FILE *output;
 uint8_t
 readu8(void)
 {
-  uint8_t val;
+	uint8_t val;
 
-  if (fread(&val, 1, 1, input) != 1)
-    {
-      return (-1); /* XXX: TODO */
-    }
+	if (fread(&val, 1, 1, input) != 1)
+	{
+		return (-1); /* XXX: TODO */
+	}
 
-  return (val);
+	return (val);
 }
 
 uint16_t
 readu16(void)
 {
-  uint16_t val;
+	uint16_t val;
 
-  if (fread(&val, 1, 2, input) != 2)
-    {
-      return (-1); /* XXX: TODO */
-    }
+	if (fread(&val, 1, 2, input) != 2)
+	{
+		return (-1); /* XXX: TODO */
+	}
 
-  return (val);
+	return (val);
 }
 
 uint32_t
 readu32(void)
 {
-  uint32_t val;
+	uint32_t val;
 
-  if (fread(&val, 1, 4, input) != 4)
-    {
-      return (-1); /* XXX: TODO */
-    }
+	if (fread(&val, 1, 4, input) != 4)
+	{
+		return (-1); /* XXX: TODO */
+	}
 
-  return (val);
+	return (val);
 }
 
 int16_t
 read16(void)
 {
-  int16_t val;
+	int16_t val;
 
-  if (fread(&val, 1, 2, input) != 2)
-    {
-      return (-1); /* XXX: TODO */
-    }
+	if (fread(&val, 1, 2, input) != 2)
+	{
+		return (-1); /* XXX: TODO */
+	}
 
-  return (val);
+	return (val);
 }
 
 int32_t
 read32(void)
 {
-  int32_t val;
+	int32_t val;
 
-  if (fread(&val, 1, 4, input) != 4)
-    {
-      return (-1); /* XXX: TODO */
-    }
+	if (fread(&val, 1, 4, input) != 4)
+	{
+		return (-1); /* XXX: TODO */
+	}
 
-  return (val);
+	return (val);
 }
 
 void
 fatal(const char *str, ...)
 {
-  va_list ap;
+	va_list ap;
 
-  fprintf(stderr, "%s: ", prg_name);
-  va_start(ap, str);
-  vfprintf(stderr, str, ap);
-  va_end(ap);
-  fprintf(stderr, "\n");
+	fprintf(stderr, "%s: ", prg_name);
+	va_start(ap, str);
+	vfprintf(stderr, str, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
 
-  exit(EXIT_FAILURE);
+	exit(EXIT_FAILURE);
 }
 
 void
 decode_target_suffix(uint8_t attr)
 {
-  fprintf(output, ".");
-  if (IS_TARGET_ZEXT(attr))
-    {
-      fprintf(output, "U");
-    }
+	fprintf(output, ".");
+	if (IS_TARGET_ZEXT(attr))
+	{
+		fprintf(output, "U");
+	}
 
-  switch (GET_TARGET_SIZE(attr))
-    {
-    case SIZE_BYTE:
-      fprintf(output, "B");
-      break;
-    case SIZE_WORD:
-      fprintf(output, "W");
-      break;
-    case SIZE_LONG:
-      fprintf(output, "L");
-      break;
-    }
+	switch (GET_TARGET_SIZE(attr))
+	{
+	case SIZE_BYTE:
+		fprintf(output, "B");
+		break;
+	case SIZE_WORD:
+		fprintf(output, "W");
+		break;
+	case SIZE_LONG:
+		fprintf(output, "L");
+		break;
+	}
 }
 
 void
 decode_address(uint8_t attr)
 {
-    switch (GET_ADDRESS_SIZE(attr))
-    {
-    case SIZE_BYTE:
-      fprintf(output, " %%%X", readu8());
-      break;
-    case SIZE_WORD:
-      fprintf(output, " %%%hX", readu16());
-      break;
-    case SIZE_LONG:
-      fprintf(output, " %%%X", readu32());
-      break;
-    default:
-      break;
-    }
+	switch (GET_ADDRESS_SIZE(attr))
+	{
+	case SIZE_BYTE:
+		fprintf(output, " %%%X", readu8());
+		break;
+	case SIZE_WORD:
+		fprintf(output, " %%%hX", readu16());
+		break;
+	case SIZE_LONG:
+		fprintf(output, " %%%X", readu32());
+		break;
+	default:
+		break;
+	}
 }
 
 void
 decode_imm(uint8_t opcode)
 {
-  uint8_t attr;
+	uint8_t attr;
 
-  attr = readu8();
+	attr = readu8();
 
-  fprintf(output, "%s", opcode_str[opcode]);
-  decode_target_suffix(attr);
-  switch (GET_TARGET_SIZE(attr))
-    {
-    case SIZE_BYTE:
-      fprintf(output, " #$%X\n", readu8());
-      break;
-    case SIZE_WORD:
-      fprintf(output, " #$%hX\n", readu16());
-      break;
-    case SIZE_LONG:
-      fprintf(output, " #$%X\n", readu32());
-      break;
-    default:
-      break;
-    }
+	fprintf(output, "%s", opcode_str[opcode]);
+	decode_target_suffix(attr);
+	switch (GET_TARGET_SIZE(attr))
+	{
+	case SIZE_BYTE:
+		fprintf(output, " #$%X\n", readu8());
+		break;
+	case SIZE_WORD:
+		fprintf(output, " #$%hX\n", readu16());
+		break;
+	case SIZE_LONG:
+		fprintf(output, " #$%X\n", readu32());
+		break;
+	default:
+		break;
+	}
 }
 
 void
 decode_ind(uint8_t opcode)
 {
-  uint8_t attr;
+	uint8_t attr;
 
-  fprintf(output, "%s", opcode_str[opcode]);
-  attr = readu8();
-  if (opcode != OP_JMP_ind)
-    {
-      decode_target_suffix(attr);
-    }
-  if (opcode_addr[opcode] & (OP_ADDR_X | OP_ADDR_Y))
-    {
-      fprintf(output, " (");
-    }
-  else
-    {
-      fprintf(output, " ");
-    }
+	fprintf(output, "%s", opcode_str[opcode]);
+	attr = readu8();
+	if (opcode != OP_JMP_ind)
+	{
+		decode_target_suffix(attr);
+	}
+	if (opcode_addr[opcode] & (OP_ADDR_X | OP_ADDR_Y))
+	{
+		fprintf(output, " (");
+	}
+	else
+	{
+		fprintf(output, " ");
+	}
 
-  decode_address(attr);
+	decode_address(attr);
 
-  if (opcode_addr[opcode] & OP_ADDR_X)
-    {
-      fprintf(output, ", X)");
-    }
-  else if (opcode_addr[opcode] & OP_ADDR_Y)
-    {
-      fprintf(output, "), Y");
-    }
-  fprintf(output, "\n");
+	if (opcode_addr[opcode] & OP_ADDR_X)
+	{
+		fprintf(output, ", X)");
+	}
+	else if (opcode_addr[opcode] & OP_ADDR_Y)
+	{
+		fprintf(output, "), Y");
+	}
+	fprintf(output, "\n");
 }
 
 void
 decode_abs(uint8_t opcode)
 {
-  uint8_t attr;
+	uint8_t attr;
 
-  fprintf(output, "%s", opcode_str[opcode]);
-  attr = readu8();
-  if (opcode != OP_JSR_abs
-      || opcode != OP_JMP_abs)
-    {
-      decode_target_suffix(attr);
-    }
-  decode_address(attr);
+	fprintf(output, "%s", opcode_str[opcode]);
+	attr = readu8();
+	if (opcode != OP_JSR_abs
+		|| opcode != OP_JMP_abs)
+	{
+		decode_target_suffix(attr);
+	}
+	decode_address(attr);
 
-  if (opcode_addr[opcode] & OP_ADDR_X)
-    {
-      fprintf(output, ", X");
-    }
-  else if (opcode_addr[opcode] & OP_ADDR_Y)
-    {
-      fprintf(output, ", Y");
-    }
-  fprintf(output, "\n");
+	if (opcode_addr[opcode] & OP_ADDR_X)
+	{
+		fprintf(output, ", X");
+	}
+	else if (opcode_addr[opcode] & OP_ADDR_Y)
+	{
+		fprintf(output, ", Y");
+	}
+	fprintf(output, "\n");
 }
 
 void
 decode(void)
 {
-  uint8_t opcode;
-  int16_t relative;
+	uint8_t opcode;
+	int16_t relative;
 
-  do {
-    opcode = readu8();
-    if (feof(input)) return;
-    switch (opcode_addr[opcode] & OP_ADDR_MODE)
-      {
-      case OP_ADDR_IMPL:
-	fprintf(output, "%s\n", opcode_str[opcode]);
-	break;
-      case OP_ADDR_REL:
-	relative = read16();
-	fprintf(output, "%s $%hX\n", opcode_str[opcode], relative);
-	break;
-      case OP_ADDR_IMM:
-	decode_imm(opcode);
-	break;
-      case OP_ADDR_IND:
-	decode_ind(opcode);
-	break;
-      case OP_ADDR_ABS:
-	decode_abs(opcode);
-	break;
-      default:
-	fprintf(output, "???\n", opcode);
-	break;
-      }
-  } while (!feof(input));
+	do {
+		opcode = readu8();
+		if (feof(input)) return;
+		switch (opcode_addr[opcode] & OP_ADDR_MODE)
+		{
+		case OP_ADDR_IMPL:
+			if (opcode_addr[opcode] & OP_ADDR_A)
+			{
+				fprintf(output, "%s A\n", opcode_str[opcode]);
+			}
+			else
+			{
+				fprintf(output, "%s\n", opcode_str[opcode]);
+			}
+			break;
+		case OP_ADDR_REL:
+			relative = read16();
+			fprintf(output, "%s $%hX\n", opcode_str[opcode], relative);
+			break;
+		case OP_ADDR_IMM:
+			decode_imm(opcode);
+			break;
+		case OP_ADDR_IND:
+			decode_ind(opcode);
+			break;
+		case OP_ADDR_ABS:
+			decode_abs(opcode);
+			break;
+		default:
+			fprintf(output, "???\n", opcode);
+			break;
+		}
+	} while (!feof(input));
+}
+
+void
+usage(int retcode)
+{
+	if (retcode == EXIT_FAILURE)
+	{
+		fprintf(stderr,
+				"Try '%s -h' for more information.\n", prg_name);
+	}
+	else
+	{
+		printf("Usage: %s [-hV] [INPUT] [OUTPUT]\n", prg_name);
+		printf("Disassemble INPUT to OUTPUT\n\n");
+		printf("With no INPUT read standard input.\n");
+		printf("With no OUTPUT write standard output.\n\n");
+		printf("\t-h\tdisplay this help and exit\n");
+		printf("\t-V\toutput version information\n");
+		printf("\nReport bugs to <%s>\n", PACKAGE_BUGREPORT);
+	}
+
+	exit(retcode);
+}
+
+void
+version(void)
+{
+	printf("%s version %s\n", PACKAGE_NAME, PACKAGE_VERSION);
+	exit(EXIT_SUCCESS);
 }
 
 int
 main(int argc, char **argv)
 {
-  prg_name = argv[0];
-  input = stdin;
-  output = stdout;
+#ifdef HAVE_LIBGEN_H
+	prg_name = basename(argv[0]);
+#else
+	prg_name = argv[0];
+#endif /* HAVE_LIBGEN_H */
+	input = stdin;
+	output = stdout;
 
-  if (argc > 2)
-    {
-      output = fopen(argv[2], "w");
-      if (output == NULL) fatal("can't open %s.", argv[2]);
-    }
+	while ((argc > 1) && (argv[1][0] == '-'))
+	{
+		switch (argv[1][1])
+		{
+		case 'h':
+			usage(EXIT_SUCCESS);
+			break;
+		case 'V':
+			version();
+			break;
+		default:
+			usage(EXIT_FAILURE);
+			break;
+		}
 
-  if (argc > 1)
-    {
-      input = fopen(argv[1], "rb");
-      if (input == NULL) fatal("can't open %s.", argv[1]);
-    }
+		argv++;
+		argc--;
+	}
 
-  decode();
+	if (argc > 2)
+	{
+		output = fopen(argv[2], "w");
+		if (output == NULL) fatal("can't open %s.", argv[2]);
+	}
+	if (argc > 1)
+	{
+		input = fopen(argv[1], "rb");
+		if (input == NULL) fatal("can't open %s.", argv[1]);
+	}
 
-  return (EXIT_SUCCESS);
+	decode();
+	return (EXIT_SUCCESS);
 }
diff --git a/lib/op.c b/lib/op.c
index 261fb89..3f19733 100644
--- a/lib/op.c
+++ b/lib/op.c
@@ -12,7 +12,7 @@ const uint8_t opcode_addr[OP_MAX] = {
   /*     */ 0xFF,
   /* PHP */ OP_ADDR_IMPL,
   /* ORA */ OP_ADDR_IMM,
-  /* ASL */ OP_ADDR_IMPL,
+  /* ASL */ OP_ADDR_IMPL | OP_ADDR_A,
   /*     */ 0xFF,
   /*     */ 0xFF,
   /* ORA */ OP_ADDR_ABS,
@@ -48,7 +48,7 @@ const uint8_t opcode_addr[OP_MAX] = {
   /*     */ 0xFF,
   /* PLP */ OP_ADDR_IMPL,
   /* AND */ OP_ADDR_IMM,
-  /* ROL */ OP_ADDR_IMPL,
+  /* ROL */ OP_ADDR_IMPL | OP_ADDR_A,
   /*     */ 0xFF,
   /* BIT */ OP_ADDR_ABS,
   /* AND */ OP_ADDR_ABS,
@@ -84,7 +84,7 @@ const uint8_t opcode_addr[OP_MAX] = {
   /*     */ 0xFF,
   /* PHA */ OP_ADDR_IMPL,
   /* EOR */ OP_ADDR_IMM,
-  /* LSR */ OP_ADDR_IMPL,
+  /* LSR */ OP_ADDR_IMPL | OP_ADDR_A,
   /*     */ 0xFF,
   /* JMP */ OP_ADDR_ABS,
   /* EOR */ OP_ADDR_ABS,
@@ -112,7 +112,7 @@ const uint8_t opcode_addr[OP_MAX] = {
   /*       6-       */
   /* RTS */ OP_ADDR_IMPL,
   /* ADC */ OP_ADDR_IND | OP_ADDR_X,
-  /*     */ 0xFF,
+  /* PER */ OP_ADDR_IMPL,
   /*     */ 0xFF,
   /*     */ 0xFF,
   /* ADC */ 0xFF,
@@ -120,7 +120,7 @@ const uint8_t opcode_addr[OP_MAX] = {
   /*     */ 0xFF,
   /* PLA */ OP_ADDR_IMPL,
   /* ADC */ OP_ADDR_IMM,
-  /* ROR */ OP_ADDR_IMPL,
+  /* ROR */ OP_ADDR_IMPL | OP_ADDR_A,
   /*     */ 0xFF,
   /* JMP */ OP_ADDR_IND,
   /* ADC */ OP_ADDR_ABS,
@@ -291,20 +291,20 @@ const uint8_t opcode_addr[OP_MAX] = {
 };
 
 const char *opcode_str[OP_MAX] = {
-  "BRK", "ORA", NULL,  NULL, NULL,  "ORA", "ASL", NULL, "PHP", "ORA", "ASLA", NULL, NULL,  "ORA", "ASL", NULL,
-  "BPL", "ORA", NULL,  NULL, NULL,  "ORA", "ASL", NULL, "CLC", "ORA", NULL,   NULL, NULL,  "ORA", "ASL", NULL,
-  "JSR", "AND", NULL,  NULL, "BIT", "AND", "ROL", NULL, "PLP", "AND", "ROLA", NULL, "BIT", "AND", "ROL", NULL,
-  "BMI", "AND", NULL,  NULL, NULL,  "AND", "ROL", NULL, "SEC", "AND", NULL,   NULL, NULL,  "AND", "ROL", NULL,
-  "RTI", "EOR", NULL,  NULL, NULL,  "EOR", "LSR", NULL, "PHA", "EOR", "LSRA", NULL, "JMP", "EOR", "LSR", NULL,
-  "BVC", "EOR", NULL,  NULL, NULL,  "EOR", "LSR", NULL, "CLI", "EOR", NULL,   NULL, NULL,  "EOR", "LSR", NULL,
-  "RTS", "ADC", NULL,  NULL, NULL,  "ADC", "ROR", NULL, "PLA", "ADC", "RORA", NULL, "JMP", "ADC", "ROR", NULL,
-  "BVS", "ADC", NULL,  NULL, NULL,  "ADC", "ROR", NULL, "SEI", "ADC", NULL,   NULL, NULL,  "ADC", "ROR", NULL,
-  NULL,  "STA", NULL,  NULL, "STY", "STA", "STX", NULL, "DEY", NULL,  "TXA",  NULL, "STY", "STA", "STX", NULL,
-  "BCC", "STA", NULL,  NULL, "STY", "STA", "STX", NULL, "TYA", "STA", "TXS",  NULL, NULL,  "STA", NULL,  NULL,
-  "LDY", "LDA", "LDX", NULL, "LDY", "LDA", "LDX", NULL, "TAY", "LDA", "TAX",  NULL, "LDY", "LDA", "LDX", NULL,
-  "BCS", "LDA", NULL,  NULL, "LDY", "LDA", "LDX", NULL, "CLV", "LDA", "TSX",  NULL, "LDY", "LDA", "LDX", NULL,
-  "CPY", "CMP", NULL,  NULL, "CPY", "CMP", "DEC", NULL, "INY", "CMP", "DEX",  NULL, "CPY", "CMP", "DEC", NULL,
-  "BNE", "CMP", NULL,  NULL, NULL,  "CMP", "DEC", NULL, "CLD", "CMP", NULL,   NULL, NULL,  "CMP", "DEC", NULL,
-  "CPX", "SBC", NULL,  NULL, "CPX", "SBC", "INC", NULL, "INX", "SBC", "NOP",  NULL, "CPX", "SBC", "INC", NULL,
-  "BEQ", "SBC", NULL,  NULL, NULL,  "SBC", "INC", NULL, "SED", "SBC", NULL,   NULL, NULL,  "SBC", "INC", NULL
+	"BRK", "ORA", NULL,  NULL, NULL,  "ORA", "ASL", NULL, "PHP", "ORA", "ASL", NULL, NULL,  "ORA", "ASL", NULL,
+	"BPL", "ORA", NULL,  NULL, NULL,  "ORA", "ASL", NULL, "CLC", "ORA", NULL,  NULL, NULL,  "ORA", "ASL", NULL,
+	"JSR", "AND", NULL,  NULL, "BIT", "AND", "ROL", NULL, "PLP", "AND", "ROL", NULL, "BIT", "AND", "ROL", NULL,
+	"BMI", "AND", NULL,  NULL, NULL,  "AND", "ROL", NULL, "SEC", "AND", NULL,  NULL, NULL,  "AND", "ROL", NULL,
+	"RTI", "EOR", NULL,  NULL, NULL,  "EOR", "LSR", NULL, "PHA", "EOR", "LSR", NULL, "JMP", "EOR", "LSR", NULL,
+	"BVC", "EOR", NULL,  NULL, NULL,  "EOR", "LSR", NULL, "CLI", "EOR", NULL,  NULL, NULL,  "EOR", "LSR", NULL,
+	"RTS", "ADC", "PER", NULL, NULL,  "ADC", "ROR", NULL, "PLA", "ADC", "ROR", NULL, "JMP", "ADC", "ROR", NULL,
+	"BVS", "ADC", NULL,  NULL, NULL,  "ADC", "ROR", NULL, "SEI", "ADC", NULL,  NULL, NULL,  "ADC", "ROR", NULL,
+	NULL,  "STA", NULL,  NULL, "STY", "STA", "STX", NULL, "DEY", NULL,  "TXA", NULL, "STY", "STA", "STX", NULL,
+	"BCC", "STA", NULL,  NULL, "STY", "STA", "STX", NULL, "TYA", "STA", "TXS", NULL, NULL,  "STA", NULL,  NULL,
+	"LDY", "LDA", "LDX", NULL, "LDY", "LDA", "LDX", NULL, "TAY", "LDA", "TAX", NULL, "LDY", "LDA", "LDX", NULL,
+	"BCS", "LDA", NULL,  NULL, "LDY", "LDA", "LDX", NULL, "CLV", "LDA", "TSX", NULL, "LDY", "LDA", "LDX", NULL,
+	"CPY", "CMP", NULL,  NULL, "CPY", "CMP", "DEC", NULL, "INY", "CMP", "DEX", NULL, "CPY", "CMP", "DEC", NULL,
+	"BNE", "CMP", NULL,  NULL, NULL,  "CMP", "DEC", NULL, "CLD", "CMP", NULL,  NULL, NULL,  "CMP", "DEC", NULL,
+	"CPX", "SBC", NULL,  NULL, "CPX", "SBC", "INC", NULL, "INX", "SBC", "NOP", NULL, "CPX", "SBC", "INC", NULL,
+	"BEQ", "SBC", NULL,  NULL, NULL,  "SBC", "INC", NULL, "SED", "SBC", NULL,  NULL, NULL,  "SBC", "INC", NULL
 };
diff --git a/lib/op.h b/lib/op.h
index 33fee5f..d93c83c 100644
--- a/lib/op.h
+++ b/lib/op.h
@@ -12,6 +12,7 @@
 # define OP_ADDR_ABS  1 << 3
 # define OP_ADDR_X    1 << 4
 # define OP_ADDR_Y    1 << 5
+# define OP_ADDR_A    1 << 6
 
 # define OP_BRK_impl  0x00
 # define OP_ORA_x_ind 0x01
diff --git a/vm/Makefile.am b/vm/Makefile.am
index cb2a849..910e88d 100644
--- a/vm/Makefile.am
+++ b/vm/Makefile.am
@@ -1,11 +1,11 @@
-include jit/Makefrag.am
-include ata/Makefrag.am
-include res/Makefrag.am
-
-noinst_LIBRARIES = $(LIBJIT) $(LIB_ATA)
-
-bin_PROGRAMS = vm
-
-vm_SOURCES = main.c
-vm_CFLAGS =-I$(top_srcdir)
-vm_LDADD = ../lib/lib65oo2.a $(LIBJIT) $(LIB_ATA) $(RES)
+include jit/Makefrag.am
+include ata/Makefrag.am
+include res/Makefrag.am
+
+noinst_LIBRARIES = $(LIBJIT) $(LIB_ATA)
+
+bin_PROGRAMS = vm
+
+vm_SOURCES = main.c
+vm_CFLAGS =-I$(top_srcdir) $(SDL2_CFLAGS)
+vm_LDADD = ../lib/lib65oo2.a $(LIBJIT) $(LIB_ATA) $(RES) $(SDL2_LIBS)
diff --git a/vm/ata/Makefrag.am b/vm/ata/Makefrag.am
index b4f3817..d3509da 100644
--- a/vm/ata/Makefrag.am
+++ b/vm/ata/Makefrag.am
@@ -1,7 +1,11 @@
-LIB_ATA = libata.a
-
-libata_a_SOURCES = ata/ata.c ata/rtc.c
-
-if USE_ATA_VGA
-libata_a_SOURCES += ata/vga.c
-endif
+LIB_ATA = libata.a
+
+libata_a_SOURCES = ata/ata.c ata/rtc.c
+
+if USE_ATA_VGA
+libata_a_SOURCES += ata/vga.c
+endif
+
+if USE_ATA_ETHERNET
+libata_a_SOURCES += ata/ethernet.c
+endif
diff --git a/vm/ata/ethernet.c b/vm/ata/ethernet.c
index 233a1bd..ce9bac5 100644
--- a/vm/ata/ethernet.c
+++ b/vm/ata/ethernet.c
@@ -1,14 +1,14 @@
-#include "isa.h"
-
-static const uint8_t mac_addr[6] = {
-  0x53, 0x54, 0x41, 0x4C, 0x49, 0x4E
-};
-
-AtaDevice ethernet_dev = {
-  "TinyEthernet",
-  0x360,
-  0x36F,
-  NULL,
-  NULL,
-  NULL
-};
+#include "ata.h"
+
+static const uint8_t mac_addr[6] = {
+  0x53, 0x54, 0x41, 0x4C, 0x49, 0x4E
+};
+
+AtaDevice ethernet_dev = {
+  "TinyEthernet",
+  0x360,
+  0x36F,
+  NULL,
+  NULL,
+  NULL
+};
diff --git a/vm/ata/rtc.c b/vm/ata/rtc.c
index c88747c..1d49707 100644
--- a/vm/ata/rtc.c
+++ b/vm/ata/rtc.c
@@ -1,45 +1,45 @@
-#include <time.h>
-#include "ata.h"
-
-#define REG_SECS    0x00
-#define REG_MINS    0x00
-#define REG_HOURS   0x00
-#define REG_WKDAY   0x06
-#define REG_DAY     0x07
-#define REG_YEAR    0x09
-#define REG_CENTURY 0x032
-#define REG_STATUSA 0x0A
-#define REG_STATUSB 0x0B
-
-static uint8_t current_reg = 0x00;
-
-void
-rtc_write(uint8_t addr, uint8_t value)
-{
-  if (addr == 0)
-    {
-      current_reg = value;
-    }
-}
-
-uint8_t
-rtc_read(uint8_t addr)
-{
-  time_t time;
-  struct tm tm;
-
-  localtime(&time);
-
-  (void)time;
-  (void)tm;
-
-  return (0x00);
-}
-
-AtaDevice rtc_dev = {
-  "RTC",
-  0x070,
-  0x071,
-  NULL,
-  NULL
-};
+#include <time.h>
+#include "ata.h"
+
+#define REG_SECS    0x00
+#define REG_MINS    0x00
+#define REG_HOURS   0x00
+#define REG_WKDAY   0x06
+#define REG_DAY     0x07
+#define REG_YEAR    0x09
+#define REG_CENTURY 0x32
+#define REG_STATUSA 0x0A
+#define REG_STATUSB 0x0B
+
+static uint8_t current_reg = 0x00;
+
+void
+rtc_write(uint8_t addr, uint8_t value)
+{
+  if (addr == 0)
+    {
+      current_reg = value;
+    }
+}
+
+uint8_t
+rtc_read(uint8_t addr)
+{
+  time_t time;
+  struct tm tm;
+
+  localtime(&time);
+
+  (void)time;
+  (void)tm;
+
+  return (0x00);
+}
+
+AtaDevice rtc_dev = {
+  "RTC",
+  0x070,
+  0x071,
+  NULL,
+  NULL
+};
diff --git a/vm/bus.h b/vm/bus.h
new file mode 100644
index 0000000..33ec96d
--- /dev/null
+++ b/vm/bus.h
@@ -0,0 +1,16 @@
+#ifndef VM_BUS_H
+# define VM_BUS_H 1
+
+# include <stddef.h>
+# include <stdint.h>
+
+typedef int (*BusRead)(uint32_t addr, void *data, size_t sz);
+typedef int (*BusWrite)(uint32_t addr, const void *data, size_t sz);
+
+typedef struct
+{
+    BusRead read;
+    BusWrite write;
+} Bus;
+
+#endif /* !VM_BUS_H */
\ No newline at end of file
diff --git a/vm/cpu.c b/vm/cpu.c
new file mode 100644
index 0000000..a4b232e
--- /dev/null
+++ b/vm/cpu.c
@@ -0,0 +1,23 @@
+#include <stdlib.h>
+#include "cpu.h"
+
+void
+invalid_opcode(Cpu *cpu)
+{
+	exit(EXIT_FAILURE);
+}
+
+void
+cpu_execute(Cpu *cpu)
+{
+	uint8_t opcode;
+
+	switch (opcode)
+	{
+	default:
+		invalid_opcode();
+		break;
+	}
+
+	cpu->PC += 1;
+}
diff --git a/vm/cpu.h b/vm/cpu.h
new file mode 100644
index 0000000..a5b4887
--- /dev/null
+++ b/vm/cpu.h
@@ -0,0 +1,16 @@
+#ifndef VM_CPU_H
+# define VM_CPU_H 1
+
+# include <stdint.h>
+
+typedef struct
+{
+	uint32_t PC;
+	uint32_t A;
+	uint32_t X;
+	uint32_t Y;
+	uint8_t SR;
+	uint32_t SP;
+} Cpu;
+
+#endif /* !VM_CPU_H */
\ No newline at end of file
diff --git a/vm/main.c b/vm/main.c
index 26a92f3..c586eac 100644
--- a/vm/main.c
+++ b/vm/main.c
@@ -1,18 +1,65 @@
-#include <stdlib.h>
-#include <stdio.h>
-
-static const char *prg_name;
-
-void
-usage(void)
-{
-  printf("Usage: %s [-hV] [-b bios]\n");
-}
-
-int
-main(int argc, char **argv)
-{
-  prg_name =  argv[0];
-
-  return (EXIT_SUCCESS);
-}
+#include "config.h"
+#include <stdlib.h>
+#include <stdio.h>
+#ifdef HAVE_LIBGEN_H
+# include <libgen.h>
+#endif /* HAVE_LIBGEN_H */
+#include <SDL.h>
+
+static const char *prg_name;
+
+static void
+usage(int retcode)
+{
+	if (retcode == EXIT_FAILURE)
+	{
+		fprintf(stderr,
+				"Try '%s -h' for more information.\n", prg_name);
+	}
+	else
+	{
+		printf("Usage: %s [-hV] [-b bios]\n", prg_name);
+		printf("\t-h\tdisplay this help and exit\n");
+		printf("\t-V\toutput version information\n");
+		printf("\nReport bugs to <%s>\n", PACKAGE_BUGREPORT);
+	}
+
+	exit(retcode);
+}
+
+static void
+version(void)
+{
+	printf("%S version %s\n", PACKAGE_NAME, PACKAGE_VERSION);
+	exit(EXIT_SUCCESS);
+}
+
+int
+main(int argc, char **argv)
+{
+#ifdef HAVE_LIBGEN_H
+	prg_name = basename(argv[0]);
+#else
+	prg_name = argv[0];
+#endif /* HAVE_LIBGEN_H */
+
+	while ((argc > 1) && (argv[1][0] == '-'))
+	{
+		switch (argv[1][1])
+		{
+		case 'h':
+			usage(EXIT_SUCCESS);
+			break;
+		case 'V':
+			version();
+			break;
+		default:
+			usage(EXIT_FAILURE);
+			break;
+		}
+
+		argv++;
+		argc--;
+	}
+	return (EXIT_SUCCESS);
+}
diff --git a/vm/net/tap-linux.c b/vm/net/tap-linux.c
new file mode 100644
index 0000000..f5156b9
--- /dev/null
+++ b/vm/net/tap-linux.c
@@ -0,0 +1,32 @@
+#include <linux/if_tun.h>
+
+/*
+ * man 7 netdevice
+ * man 4 tap
+ */
+
+void
+tap_new(void)
+{
+  int fd;
+  struct ifreq req;
+
+  fd = open("/dev/net/tun", O_RDWR);
+  if (fd < 0)
+    {
+      return;
+    }
+
+  memset(&req, 0, sizeof(struct ifreq));
+  req.ifr_flags = IFF_TAP | IFF_NO_PI;
+  /*
+   * malloc(IFNAMSIZ);
+   * tun_alloc(xxxx, IFF_TAP);
+   */
+  strncpy(req.ifr_name, "todo", 5);
+  if (ioctl(fd, TUNSETIFF, &req) < 0)
+    {
+      return;
+    }
+}
+
diff --git a/vm/vm.h b/vm/vm.h
new file mode 100644
index 0000000..2e1c5b3
--- /dev/null
+++ b/vm/vm.h
@@ -0,0 +1,17 @@
+#ifndef VM_VM_H
+# define VM_VM_H 1
+
+# include "cpu.h"
+# include "bus.h"
+
+# define VM_MAX_CPU 8
+
+typedef struct
+{
+	int cpu_count;
+	Cpu cpus[VM_MAX_CPU];
+
+	Bus bus;
+} Vm;
+
+#endif /* !VM_VM_H */