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-rw-r--r--src/nesout.c352
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+/*
+
+ 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
+*/
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