Added initial files for CPC output.

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
+*/