Started on Gameboy support.

1 files changed, 432 insertions, 0 deletions

diff --git a/src/gbout.c b/src/gbout.c
new file mode 100644
index 0000000..8fa3e7a
--- /dev/null
+++ b/src/gbout.c
@@ -0,0 +1,432 @@
+/*
+
+    casm - Simple, portable assembler
+
+    Copyright (C) 2003-2015  Ian Cowburn (ianc@noddybox.demon.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 handler.
+
+*/
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "global.h"
+#include "expr.h"
+#include "codepage.h"
+#include "gbout.h"
+
+
+/* ---------------------------------------- MACROS & TYPES
+*/
+
+enum option_t
+{
+    OPT_COLOUR,
+    OPT_SUPER,
+    OPT_CART_RAM,
+    OPT_CART_TYPE,
+    OPT_RST,
+    OPT_IRQ
+};
+
+static const ValueTable option_set[] =
+{
+    {"gameboy-colour",          OPT_COLOUR},
+    {"gameboy-color",           OPT_COLOUR},
+    {"gameboy-super",           OPT_SUPER},
+    {"gameboy-cart-ram",        OPT_CART_RAM},
+    {"gameboy-cart-type",       OPT_CART_RAM},
+    {"gameboy-irq",             OPT_IRQ},
+    {NULL}
+};
+
+typedef enum
+{
+    IRQ_VBLANK,
+    IRQ_LCD,
+    IRQ_TIMER,
+    IRQ_SERIAL,
+    IRQ_JOYPAD
+} IRQ_Type;
+
+static ValueTable       irq_table[] =
+{
+    {"vbl",             IRQ_VBLANK},
+    {"lcd",             IRQ_LCD},
+    {"timer",           IRQ_TIMER},
+    {"serial",          IRQ_SERIAL},
+    {"joypad",          IRQ_JOYPAD},
+    {NULL}
+};
+
+static struct
+{
+    int         is_colour;
+    int         is_super;
+    int         cart_ram;
+    int         cart_type;
+    int         irq_vector[5];
+} option =
+{
+    FALSE, FALSE, -1, -1,
+    {-1, -1, -1, -1, -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, int maxlen)
+{
+    while(*str && maxlen--)
+    {
+        addr = PokeB(mem, addr, CodeFromNative(CP_ASCII, *str++));
+    }
+
+    return addr;
+}
+
+
+static int PokeCode(Byte *mem, int addr, const int *code)
+{
+    while(*code != -1)
+    {
+        addr = PokeB(mem, addr, *code++);
+    }
+
+    return addr;
+}
+
+
+
+/* ---------------------------------------- INTERFACES
+*/
+const ValueTable *GBOutputOptions(void)
+{
+    return option_set;
+}
+
+CommandStatus GBOutputSetOption(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_COLOUR:
+            option.is_colour = ParseTrueFalse(argv[0], TRUE);
+            break;
+
+        case OPT_SUPER:
+            option.is_super = ParseTrueFalse(argv[0], TRUE);
+            break;
+
+        case OPT_CART_RAM:
+            CMD_EXPR(argv[0], option.cart_ram);
+            break;
+
+        case OPT_CART_TYPE:
+            CMD_EXPR(argv[0], option.cart_type);
+            break;
+
+        case OPT_IRQ:
+            CMD_ARGC_CHECK(2);
+            CMD_TABLE(argv[0], irq_table, val);
+            CMD_EXPR(argv[1], f);
+            option.irq_vector[val->value] = f;
+            break;
+
+        default:
+            break;
+    }
+
+    return CMD_OK;
+
+}
+
+int GBOutput(const char *filename, const char *filename_bank,
+              MemoryBank **bank, int count, char *error, size_t error_size)
+{
+    static const int logo[] =
+    {
+        0xCE, 0xED, 0x66, 0x66, 0xCC, 0x0D, 0x00, 0x0B, 0x03, 0x73, 0x00,
+        0x83, 0x00, 0x0C, 0x00, 0x0D, 0x00, 0x08, 0x11, 0x1F, 0x88, 0x89,
+        0x00, 0x0E, 0xDC, 0xCC, 0x6E, 0xE6, 0xDD, 0xDD, 0xD9, 0x99, 0xBB,
+        0xBB, 0x67, 0x63, 0x6E, 0x0E, 0xEC, 0xCC, 0xDD, 0xDC, 0x99, 0x9F,
+        0xBB, 0xB9, 0x33, 0x3E, -1
+    };
+
+    FILE *fp = fopen(filename, "wb");
+    int f;
+    int offset;
+    int rom_size;
+    unsigned global_csum = 0;
+    Byte hdr_csum = 0;
+    Byte *mem;
+
+    if (!fp)
+    {
+        snprintf(error, error_size, "Failed to create %s", filename);
+        return FALSE;
+    }
+
+    /* Check bank sizes and layouts
+    */
+    if (count == 1 && (bank[0]->min_address_used < 0x150 ||
+                        bank[0]->max_address_used > 0x7fff))
+    {
+        snprintf(error, error_size, "A simple ROM must be in the address "
+                                        "space 0x150 to 0x7fff");
+        return FALSE;
+    }
+
+    if (count > 1 && (bank[0]->min_address_used < 0x150 ||
+                        bank[0]->max_address_used > 0x3fff))
+    {
+        snprintf(error, error_size, "Bank zero of a banked ROM must be in the "
+                                        "address space 0x150 to 0x3fff");
+        return FALSE;
+    }
+
+    for(f = 1 ; f < count; f++)
+    {
+        if (bank[f]->min_address_used < 0x4000 ||
+               bank[f]->max_address_used > 0x7fff)
+        {
+            snprintf(error, error_size,
+                        "Bank %u must be in the address space "
+                                    "0x4000 to 0x7fff", bank[f]->number);
+            return FALSE;
+        }
+    }
+
+    if (option.cart_type == -1)
+    {
+        if (count == 1)
+        {
+            option.cart_type = 0;
+        }
+        else
+        {
+            option.cart_type = 1;
+        }
+
+        if (option.cart_ram != -1)
+        {
+            option.cart_type = 3;
+        }
+    }
+
+    if (count == 1)
+    {
+        rom_size = 0;
+    }
+    else
+    {
+        rom_size = (count / 4) + 1;
+    }
+
+    mem = bank[0]->memory;
+
+    /* Create the RST handlers
+    */
+    for(f = 0; f < 8; f++)
+    {
+        int addr = f * 8;
+
+        addr = PokeB(mem, addr, 0xc3);
+        addr = PokeW(mem, addr, 0x100);
+    }
+
+    /* Create the IRQ handlers
+    */
+    for(f = 0; f < 5; f++)
+    {
+        int addr = (f * 8) + 0x40;
+
+        if (option.irq_vector[f] == -1)
+        {
+            addr = PokeB(mem, addr, 0xd9);
+        }
+        else
+        {
+            addr = PokeB(mem, addr, 0xc3);
+            addr = PokeW(mem, addr, option.irq_vector[f]);
+        }
+    }
+
+    /* Create the entry point
+    */
+    PokeB(mem, 0x100, 0);
+    PokeB(mem, 0x101, 0xc3);
+    PokeW(mem, 0x102, bank[0]->min_address_used);
+
+    /* Title (new smaller size)
+    */
+    PokeS(mem, 0x134, filename, 11);
+
+    /* GBC flag
+    */
+    if (option.is_colour)
+    {
+        PokeB(mem, 0x143, 0xc0);
+    }
+
+    /* Super Gameboy flag
+    */
+    if (option.is_super)
+    {
+        PokeB(mem, 0x146, 3);
+    }
+
+    /* Type/ROM size
+    */
+    PokeB(mem, 0x147, option.cart_type);
+    PokeB(mem, 0x148, rom_size);
+
+    /* RAM size
+    */
+    switch(option.cart_ram)
+    {
+        case 2:
+            PokeB(mem, 0x149, 1);
+            break;
+
+        case 8:
+            PokeB(mem, 0x149, 2);
+            break;
+
+        case 32:
+            PokeB(mem, 0x149, 3);
+            break;
+
+        case 128:
+            PokeB(mem, 0x149, 4);
+            break;
+
+        case 64:
+            PokeB(mem, 0x149, 5);
+            break;
+
+        default:
+            PokeB(mem, 0x149, 0);
+            break;
+    }
+
+    /* To be sold everywhere
+    */
+    PokeB(mem, 0x14a, 1);
+
+    /* Old licensee
+    */
+    if (option.is_super)
+    {
+        PokeB(mem, 0x14a, 0x33);
+    }
+    else
+    {
+        PokeB(mem, 0x14a, 0);
+    }
+
+    /* Header checksum
+    */
+    for(f = 0x134 ; f < 0x14d; f++)
+    {
+        hdr_csum -= mem[f];
+    }
+
+    PokeB(mem, 0x14d, hdr_csum);
+
+    /* Global checksum
+    */
+    if (count == 1)
+    {
+        for(f = 0x150; f < 0x8000; f++)
+        {
+            global_csum += mem[f];
+        }
+    }
+    else
+    {
+        int r;
+
+        for(f = 0x150; f < 0x4000; f++)
+        {
+            global_csum += mem[f];
+        }
+
+        for(r = 1; r < count; r++)
+        {
+            for(f = 0x4000; f < 0x8000; f++)
+            {
+                global_csum += bank[r]->memory[f];
+            }
+        }
+    }
+
+    PokeW(mem, 0x14e, global_csum);
+
+    /* Output the ROM contents
+    */
+    if (count == 1)
+    {
+        fwrite(mem, 0x8000, 1, fp);
+    }
+    else
+    {
+        int r;
+
+        fwrite(mem, 0x4000, 1, fp);
+
+        for(r = 1; r < count; r++)
+        {
+            for(f = 0x4000; f < 0x8000; f++)
+            {
+                fwrite(bank[r]->memory + 0x4000, 0x4000, 1, fp);
+            }
+        }
+    }
+
+
+    fclose(fp);
+
+    return TRUE;
+}
+
+
+/*
+vim: ai sw=4 ts=8 expandtab
+*/