First pass at NES ROM support.

8 files changed, 514 insertions, 7 deletions

diff --git a/src/Makefile b/src/Makefile
index fe9fc6d..e95a5c8 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -48,7 +48,8 @@ SOURCE	=	casm.c		\
 		zx81out.c	\
 		gbout.c		\
 		snesout.c	\
-		libout.c
+		libout.c	\
+		nesout.c
 
 OBJECTS	=	casm.o		\
 		expr.o		\
@@ -74,7 +75,8 @@ OBJECTS	=	casm.o		\
 		zx81out.o	\
 		gbout.o		\
 		snesout.o	\
-		libout.o
+		libout.o	\
+		nesout.o
 
 $(TARGET): $(OBJECTS)
 	$(CC) $(CLAGS) -o $(TARGET) $(OBJECTS)
@@ -89,8 +91,8 @@ clean:
 alias.o: alias.c global.h basetype.h util.h state.h alias.h
 casm.o: casm.c global.h basetype.h util.h state.h expr.h label.h macro.h \
  cmd.h parse.h codepage.h stack.h listing.h alias.h output.h rawout.h \
- specout.h t64out.h zx81out.h gbout.h snesout.h libout.h z80.h 6502.h \
- gbcpu.h 65c816.h spc700.h
+ specout.h t64out.h zx81out.h gbout.h snesout.h libout.h nesout.h z80.h \
+ 6502.h gbcpu.h 65c816.h spc700.h
 codepage.o: codepage.c global.h basetype.h util.h state.h codepage.h \
  parse.h cmd.h
 expr.o: expr.c global.h basetype.h util.h state.h expr.h label.h
@@ -106,8 +108,11 @@ listing.o: listing.c global.h basetype.h util.h state.h label.h macro.h \
  cmd.h parse.h expr.h varchar.h listing.h
 macro.o: macro.c global.h basetype.h util.h state.h codepage.h parse.h \
  cmd.h varchar.h macro.h
+nesout.o: nesout.c global.h basetype.h util.h state.h expr.h codepage.h \
+ parse.h cmd.h nesout.h
 output.o: output.c global.h basetype.h util.h state.h output.h parse.h \
- cmd.h rawout.h specout.h t64out.h zx81out.h gbout.h snesout.h libout.h
+ cmd.h rawout.h specout.h t64out.h zx81out.h gbout.h snesout.h libout.h \
+ nesout.h
 parse.o: parse.c global.h basetype.h util.h state.h codepage.h parse.h \
  cmd.h
 rawout.o: rawout.c global.h basetype.h util.h state.h rawout.h parse.h \
diff --git a/src/casm.c b/src/casm.c
index f1de63b..c85c578 100644
--- a/src/casm.c
+++ b/src/casm.c
@@ -691,6 +691,8 @@ int main(int argc, char *argv[])
     PushValTableHandler(ZX81OutputOptions(), ZX81OutputSetOption);
     PushValTableHandler(GBOutputOptions(), GBOutputSetOption);
     PushValTableHandler(SNESOutputOptions(), SNESOutputSetOption);
+    PushValTableHandler(LibOutputOptions(), LibOutputSetOption);
+    PushValTableHandler(NESOutputOptions(), NESOutputSetOption);
 
     ClearState();
 
diff --git a/src/example/Makefile b/src/example/Makefile
index 3c57e50..e92b2ec 100644
--- a/src/example/Makefile
+++ b/src/example/Makefile
@@ -20,7 +20,7 @@
 # Makefile for examples
 #
 
-ALL	= spectrum.tap c64.t64 zx81.p gb.gb vcs.bin snes.sfc
+ALL	= spectrum.tap c64.t64 zx81.p gb.gb vcs.bin snes.sfc nes.nes
 CASM	= ../casm
 
 all: $(ALL) $(CASM)
@@ -48,5 +48,8 @@ vcs.bin: vcs.asm $(CASM)
 snes.sfc: snes.asm $(CASM)
 	$(CASM) snes.asm
 
+nes.nes: nes.asm $(CASM)
+	$(CASM) nes.asm
+
 clean:
 	rm -f $(ALL)
diff --git a/src/example/nes.asm b/src/example/nes.asm
new file mode 100644
index 0000000..c10ca66
--- /dev/null
+++ b/src/example/nes.asm
@@ -0,0 +1,82 @@
+	processor 6502
+
+	option  output-file,"nes.nes"
+	option  output-format,nes
+
+	option  nes-vector,reset,start
+	option  nes-vector,nmi,nmi
+	option  nes-vector,brk,nmi
+
+start:	org	$c000
+
+	;
+	; Code taken from NES example
+	;
+
+	sei			; disable IRQs
+	cld			; disable decimal mode
+	ldx	#$40
+	stx	$4017		; dsiable APU frame IRQ
+	ldx	#$ff		; Set up stack
+	txs			;  .
+	inx			; now X = 0
+	stx	$2000		; disable NMI
+	stx	$2001		; disable rendering
+	stx	$4010		; disable DMC IRQs
+
+	;; first wait for vblank to make sure PPU is ready
+vblankwait1:
+	bit	$2002
+	bpl	vblankwait1
+
+clear_memory:
+	lda	#$00
+	sta	$0000, x
+	sta	$0100, x
+	sta	$0200, x
+	sta	$0300, x
+	sta	$0400, x
+	sta	$0500, x
+	sta	$0600, x
+	sta	$0700, x
+	inx
+	bne	clear_memory
+
+	;; second wait for vblank, PPU is ready after this
+vblankwait2:
+	bit	$2002
+	bpl	vblankwait2
+
+clear_palette:	
+	;; Need clear both palettes to $00. Needed for Nestopia. Not
+	;; needed for FCEU* as they're already $00 on powerup.
+	lda	$2002		; Read PPU status to reset PPU address
+	lda	#$3f		; Set PPU address to BG palette RAM ($3F00)
+	sta	$2006
+	lda	#$00
+	sta 	$2006
+
+	ldx	#$20		; Loop $20 times (up to $3F20)
+	lda	#$00		; Set each entry to $00
+.loop
+	sta	$2007
+	dex
+	bne	loop
+
+	lda	#%01000000	; intensify blues
+	sta	$2001
+
+forever:
+	jmp	forever
+
+nmi:
+	rti
+
+
+;
+; Dummy VROM
+;
+	org 0
+	bank 1
+
+	db	0
diff --git a/src/nesout.c b/src/nesout.c
new file mode 100644
index 0000000..7877e12
--- /dev/null
+++ b/src/nesout.c
@@ -0,0 +1,352 @@
+/*
+
+    casm - Simple, portable assembler
+
+    Copyright (C) 2003-2015  Ian Cowburn (ianc@noddybox.co.uk)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    -------------------------------------------------------------------------
+
+    NES ROM output handler.
+
+    Notes:
+
+        * ROM is 0x8000 to 0xffff (just 0xc000 to 0xffff if 16K ROM)
+
+        * VROM is at 0x0000 to 0x1fff.
+
+*/
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "global.h"
+#include "expr.h"
+#include "codepage.h"
+#include "nesout.h"
+
+
+/* ---------------------------------------- MACROS & TYPES
+*/
+
+enum option_t
+{
+    OPT_VECTOR,
+    OPT_TV_FORMAT,
+    OPT_MAPPER
+};
+
+static const ValueTable option_set[] =
+{
+    {"nes-vector",              OPT_VECTOR},
+    {"nes-tv-format",           OPT_TV_FORMAT},
+    {"nes-mapper",              OPT_MAPPER},
+    {NULL}
+};
+
+typedef enum
+{
+    VECTOR_RESET,
+    VECTOR_NMI,
+    VECTOR_BRK
+} VectorType;
+
+static ValueTable       vector_table[] =
+{
+    {"reset",           VECTOR_RESET},
+    {"nmi",             VECTOR_NMI},
+    {"brk",             VECTOR_BRK},
+    {NULL}
+};
+
+typedef enum
+{
+    PAL = 1,
+    NTSC = 0
+} TVFormat;
+
+static ValueTable       format_table[] =
+{
+    {"pal",             PAL},
+    {"NTSC",            NTSC},
+    {NULL}
+};
+
+
+static struct
+{
+    int         vector[3];
+    TVFormat    tv_format;
+    int         mapper;
+} option =
+{
+    {-1, -1, -1}, PAL, 0
+};
+
+
+/* ---------------------------------------- PRIVATE FUNCTIONS
+*/
+
+static int PokeB(Byte *mem, int addr, Byte b)
+{
+    mem[addr++] = b;
+    return (addr % 0x10000);
+}
+
+
+static int PokeW(Byte *mem, int addr, int w)
+{
+    addr = PokeB(mem, addr, w & 0xff);
+    return PokeB(mem, addr, (w & 0xff00) >> 8);
+}
+
+
+static int PokeS(Byte *mem, int addr, const char *str, int maxlen, char pad)
+{
+    while(*str && maxlen--)
+    {
+        addr = PokeB(mem, addr, CodeFromNative(CP_ASCII, *str++));
+    }
+
+    while(maxlen-- > 0)
+    {
+        addr = PokeB(mem, addr, CodeFromNative(CP_ASCII, pad));
+    }
+
+    return addr;
+}
+
+static unsigned CalcChecksum(Byte *p, int len, unsigned csum)
+{
+    while(len-- > 0)
+    {
+        csum += *p++;
+    }
+
+    return csum & 0xffff;
+}
+
+
+/* ---------------------------------------- INTERFACES
+*/
+const ValueTable *NESOutputOptions(void)
+{
+    return option_set;
+}
+
+CommandStatus NESOutputSetOption(int opt, int argc, char *argv[],
+                                  int quoted[], char *err, size_t errsize)
+{
+    const ValueTable *val;
+    int f;
+
+    CMD_ARGC_CHECK(1);
+
+    switch(opt)
+    {
+        case OPT_VECTOR:
+            CMD_ARGC_CHECK(2);
+            CMD_TABLE(argv[0], vector_table, val);
+            CMD_EXPR(argv[1], f);
+            option.vector[val->value] = f;
+            break;
+
+        case OPT_TV_FORMAT:
+            CMD_TABLE(argv[0], format_table, val);
+            option.tv_format = val->value;
+            break;
+
+        case OPT_MAPPER:
+            CMD_EXPR(argv[1], f);
+            option.mapper = f;
+            break;
+
+        default:
+            break;
+    }
+
+    return CMD_OK;
+
+}
+
+int NESOutput(const char *filename, const char *filename_bank,
+              MemoryBank **bank, int count, char *error, size_t error_size)
+{
+    FILE *fp;
+    Byte *mem;
+    int num_rom;
+    int num_vrom;
+    int is_16k;
+    int first_code;
+    int start;
+    int f;
+
+    /* Go through the banks and see which are code (ROM), and which char (VROM)
+    */
+    num_rom = 0;
+    num_vrom = 0;
+    is_16k = FALSE;
+    first_code = -1;
+
+    for(f = 0; f < count; f++)
+    {
+        if (bank[f]->max_address_used < 0x2000)
+        {
+            num_vrom++;
+        }
+        else if (bank[f]->min_address_used >= 0xc000)
+        {
+            if (first_code == -1)
+            {
+                first_code = f;
+            }
+
+            is_16k = TRUE;
+            num_rom++;
+        }
+        else if (bank[f]->min_address_used >= 0x8000)
+        {
+            if (first_code == -1)
+            {
+                first_code = f;
+            }
+
+            is_16k = FALSE;
+            num_rom++;
+        }
+        else
+        {
+            snprintf(error, error_size,
+                        "Banks should use memory in the range 0x0000 - 0x1fff "
+                        "to indicate they are\nvideo ROM, 0x8000 - 0xffff to "
+                        "indicate they are program ROM or 0xc000 - 0xffff\n"
+                        "to indicate a single 16K ROM segment.");
+
+            return FALSE;
+        }
+    }
+
+    if (first_code == -1)
+    {
+        snprintf(error, error_size,
+                    "No ROM code banks present;\n"
+                    "Banks should use memory in the range 0x0000 - 0x1fff "
+                    "to indicate they are\nvideo ROM, 0x8000 - 0xffff to "
+                    "indicate they are program ROM or 0xc000 - 0xffff\n"
+                    "to indicate a single 16K ROM segment.");
+
+        return FALSE;
+    }
+
+    if (!(fp = fopen(filename, "wb")))
+    {
+        snprintf(error, error_size, "Failed to create %s", filename);
+        return FALSE;
+    }
+
+    /* Setup vectors
+    */
+    mem = bank[first_code]->memory;
+
+    start = option.vector[VECTOR_RESET];
+
+    if (start == -1)
+    {
+        start = is_16k ? 0xc000 : 0x8000;
+
+        fprintf(stderr, "WARNING: No reset vector provided; assuming 0x%4.4x\n",
+                                        start);
+    }
+
+    PokeW(mem, 0xfffc, start);
+
+    if (option.vector[VECTOR_NMI] != -1)
+    {
+        PokeW(mem, 0xfffa, option.vector[VECTOR_NMI]);
+    }
+    else
+    {
+        fprintf(stderr, "WARNING: NMI vector not set\n");
+    }
+
+    if (option.vector[VECTOR_BRK] != -1)
+    {
+        PokeW(mem, 0xfffe, option.vector[VECTOR_BRK]);
+    }
+
+    /* Output header
+    */
+    fputs("NES", fp);
+    fputc(26, fp);
+
+    if (is_16k)
+    {
+        fputc(1, fp);
+    }
+    else
+    {
+        fputc(num_rom * 2, fp);
+    }
+
+    fputc(num_vrom, fp);
+
+    fputc((option.mapper & 0x0f) << 4, fp);
+    fputc(option.mapper & 0xf0, fp);
+
+    fputc(0, fp);
+
+    fputc(option.tv_format, fp);
+
+    for(f = 0; f < 5; f++)
+    {
+        fputc(0, fp);
+    }
+
+    /* Output ROM contents, first code segments
+    */
+    for(f = 0; f < count; f++)
+    {
+        if (bank[f]->min_address_used > 0x2000)
+        {
+            if (is_16k)
+            {
+                fwrite(bank[f]->memory + 0xc000, 0x4000, 1, fp);
+            }
+            else
+            {
+                fwrite(bank[f]->memory + 0x8000, 0x8000, 1, fp);
+            }
+        }
+    }
+
+    /* Then video ROM banks
+    */
+    for(f = 0; f < count; f++)
+    {
+        if (bank[f]->min_address_used < 0x2000)
+        {
+            fwrite(bank[f]->memory, 0x2000, 1, fp);
+        }
+    }
+
+    fclose(fp);
+
+    return TRUE;
+}
+
+
+/*
+vim: ai sw=4 ts=8 expandtab
+*/
diff --git a/src/nesout.h b/src/nesout.h
new file mode 100644
index 0000000..722db02
--- /dev/null
+++ b/src/nesout.h
@@ -0,0 +1,56 @@
+/*
+
+    casm - Simple, portable assembler
+
+    Copyright (C) 2003-2015  Ian Cowburn (ianc@noddybox.co.uk)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    -------------------------------------------------------------------------
+
+    Gameboy ROM output
+
+*/
+
+#ifndef CASM_NESOUT_H
+#define CASM_NESOUT_H
+
+#include "parse.h"
+#include "state.h"
+#include "cmd.h"
+
+/* ---------------------------------------- INTERFACES
+*/
+
+
+/* NES Output options
+*/
+const ValueTable *NESOutputOptions(void);
+
+CommandStatus NESOutputSetOption(int opt, int argc, char *argv[],
+                                 int quoted[], char *error,
+                                 size_t error_size);
+
+
+/* NES ROM output of assembly.  Returns TRUE if OK, FALSE for failure.
+*/
+int NESOutput(const char *filename, const char *filename_bank,
+              MemoryBank **bank, int count,
+              char *error, size_t error_size);
+
+#endif
+
+/*
+vim: ai sw=4 ts=8 expandtab
+*/
diff --git a/src/output.c b/src/output.c
index ac05216..1067b96 100644
--- a/src/output.c
+++ b/src/output.c
@@ -54,7 +54,8 @@ typedef enum
     ZX81,
     GAMEBOY,
     SNES,
-    LIBRARY
+    LIBRARY,
+    NES
 } Format;
 
 static char             output[4096] = "output";
@@ -71,6 +72,7 @@ static ValueTable       format_table[] =
     {"gameboy",         GAMEBOY},
     {"snes",            SNES},
     {"lib",             LIBRARY},
+    {"nes",             NES},
     {NULL}
 };
 
@@ -160,6 +162,10 @@ int OutputCode(void)
             return LibOutput(output, output_bank, bank, count,
                              error, sizeof error);
 
+        case NES:
+            return NESOutput(output, output_bank, bank, count,
+                             error, sizeof error);
+
         default:
             break;
     }
diff --git a/src/output.h b/src/output.h
index 03131e4..b2e208c 100644
--- a/src/output.h
+++ b/src/output.h
@@ -38,6 +38,7 @@
 #include "gbout.h"
 #include "snesout.h"
 #include "libout.h"
+#include "nesout.h"
 
 /* ---------------------------------------- INTERFACES
 */