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Diffstat (limited to 'src/cpcout.c')
| -rw-r--r-- | src/cpcout.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/src/cpcout.c b/src/cpcout.c new file mode 100644 index 0000000..6dbafc1 --- /dev/null +++ b/src/cpcout.c @@ -0,0 +1,274 @@ +/* + + 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/>. + + ------------------------------------------------------------------------- + + Commodore CPC tape output handler. + +*/ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#include "global.h" +#include "codepage.h" +#include "cpcout.h" +#include "expr.h" + + +/* ---------------------------------------- MACROS & TYPES +*/ + +enum option_t +{ + OPT_START_ADDR, +}; + +static const ValueTable option_set[] = +{ + {"cpc-start", OPT_START_ADDR}, + {NULL} +}; + +typedef struct +{ + int start_addr; +} Options; + +static Options options = {-1}; + +/* ---------------------------------------- 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) +{ + while(*str) + { + addr = PokeB(mem, addr, CodeFromNative(CP_ASCII, *str++)); + } + + return addr; +} + + +static void WriteByte(FILE *fp, Byte b) +{ + putc(b, fp); +} + + +static void WriteWord(FILE *fp, int w) +{ + WriteByte(fp, w & 0xff); + WriteByte(fp, (w & 0xff00) >> 8); +} + + +static void WriteLong(FILE *fp, unsigned long l) +{ + int f; + + for(f = 0; f < 4; f++) + { + WriteByte(fp, l & 0xff); + l >>= 8u; + } +} + + +static void WriteString(FILE *fp, const char *p, int len, + Byte fill, Codepage cp) +{ + while(len--) + { + WriteByte(fp, *p ? CodeFromNative(cp, *p++) : CodeFromNative(cp, fill)); + } +} + + +/* ---------------------------------------- INTERFACES +*/ +const ValueTable *CPCOutputOptions(void) +{ + return option_set; +} + +CommandStatus CPCOutputSetOption(int opt, int argc, char *argv[], int quoted[], + char *err, size_t errsize) +{ + CommandStatus stat = CMD_OK; + + CMD_ARGC_CHECK(1); + + switch(opt) + { + case OPT_START_ADDR: + CMD_EXPR(argv[0], options.start_addr); + break; + + default: + break; + } + + return stat; +} + +int CPCOutput(const char *filename, const char *filename_bank, + MemoryBank **bank, int count, char *error, size_t error_size) +{ + FILE *fp = fopen(filename, "wb"); + int f; + int offset; + + if (!fp) + { + snprintf(error, error_size, "Failed to create %s", filename); + return FALSE; + } + + /* Write signature + */ + WriteString(fp, "C64 tape image file", 32, 0, CP_ASCII); + + /* Write directory header + */ + WriteWord(fp, 0x200); + WriteWord(fp, count); + WriteWord(fp, count); + WriteString(fp, filename, 24, ' ', CP_ASCII); + + /* Offset to tape data + */ + offset = 64 + 32 * count; + + /* Write directory entries + */ + for(f = 0; f < count; f++) + { + int min, max, len; + + min = bank[f]->min_address_used; + max = bank[f]->max_address_used; + + /* If this is the first bank, we're going to prepend some BASIC + */ + if (f == 0) + { + if (min < 0x810) + { + snprintf(error, error_size, "First bank starts below a safe " + "area to add BASIC loader"); + + return FALSE; + } + + min = 0x801; /* Start of BASIC */ + } + + len = max - min + 1; + + WriteByte(fp, 1); + WriteByte(fp, 0x82); + WriteWord(fp, min); + WriteWord(fp, max + 1); + WriteLong(fp, offset); + + if (count == 1) + { + WriteString(fp, filename, 16, ' ', CP_CBM); + } + else + { + char fn[16]; + + snprintf(fn, sizeof fn, filename_bank, bank[f]->number); + WriteString(fp, fn, 16, ' ', CP_CBM); + } + + /* +2 is to include the 2-byte PRG header + offset += len + 2; + */ + offset += len; + } + + /* Write actual contents + */ + for(f = 0; f < count; f++) + { + Byte *mem; + int min, max, len; + + mem = bank[f]->memory; + + min = bank[f]->min_address_used; + max = bank[f]->max_address_used; + + /* If this is the first bank, we're going to prepend some BASIC. + Note that output drivers are allowed to manipulate memory directly. + */ + if (f == 0) + { + char sys[16]; + int a = 0x803; + int next; + + snprintf(sys, sizeof sys, "%u", min); + + a = PokeW(mem, a, 10); + a = PokeB(mem, a, 0x9e); + a = PokeS(mem, a, sys); + a = PokeB(mem, a, 0x00); + + next = a; + + a = PokeW(mem, a, 0x00); + + PokeW(mem, 0x801, next); + + min = 0x801; + } + + len = max - min + 1; + + fwrite(mem + min, len, 1, fp); + } + + fclose(fp); + + return TRUE; +} + + +/* +vim: ai sw=4 ts=8 expandtab +*/ |