File content as of revision 0:5bd52e196edb:

/* hwapu - SPC music playback tools for real snes apu
 * Copyright (C) 2004-2005  Raphael Assenat <raph@raphnet.net>
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <stdio.h>
#include "apuplay.h"
#include "apu.h"
#include "dsploader.h"
#include "bootcode.h"
#ifdef PROGRESS_SPINNER
#include "pspin.h"
#endif

extern int g_debug;
extern int g_verbose;
extern int g_exit_now;
extern int g_playing;
extern int g_progress;

int LoadAPU_embedded(FILE *fptr)
{
    int i=0, j=0, count=0, val=0;
    
    unsigned char spc_pcl;
    unsigned char spc_pch;
    unsigned char spc_a;
    unsigned char spc_x;
    unsigned char spc_y;
    unsigned char spc_sw;
    unsigned char spc_sp;

//  unsigned char spcdata[65536];
//  unsigned char spcram[64];

    unsigned char dsp_kon=0;
    unsigned char dsp_flg=0;
    unsigned char dsp_esa=0;
    unsigned char dsp_edl=0;
    
    unsigned char workbuf[64];
    
    int echosize, echoregion, bootptr, readcount=0;
    
    fseek(fptr, 0x25, SEEK_SET);

    fread(&spc_pcl, 1, 1, fptr);
    fread(&spc_pch, 1, 1, fptr);
    fread(&spc_a, 1, 1, fptr);
    fread(&spc_x, 1, 1, fptr);
    fread(&spc_y, 1, 1, fptr);
    fread(&spc_sw, 1, 1, fptr);
    fread(&spc_sp, 1, 1, fptr);

    if (g_debug) {
        printf("PC: %02x%02x\n", spc_pch, spc_pcl);
        printf("A: %02X\n", spc_a);
        printf("X: %02X\n", spc_x);
        printf("Y: %02X\n", spc_y);
        printf("SW: %02X\n", spc_sw);
        printf("SP: %02X\n", spc_sp);
    }

    apu_reset();
    apu_initTransfer(0x0002);

    if (g_verbose) 
        printf("Restoring dsp registers...\n");

    if (g_exit_now || !g_playing) { apu_reset(); return 0; }
    
    /* first, we send a small program called the dsploader which we will
     * use to restore the DSP registers (with our modified KON and FLG to
     * keep it silent) */
    if (apu_writeBytes(dsploader, 16)) {
        fprintf(stderr, "Timeout sending dsploader\n");
        return -1;
    }
    apu_endTransfer(0x0002);    
    
    if (g_exit_now || !g_playing) { apu_reset(); return 0; }

    /* restore the 128 dsp registers one by one with the help of the dsp loader. */
    fseek(fptr, OFFSET_DSPDATA, SEEK_SET);
    for (i=0; i<128; i+=64)
    {
        fread(workbuf, 64, 1, fptr);
        for (j=0; j<64; j++)
        {
            /* mute all voices and stop all notes */
            if (i+j == DSP_FLG) {
                dsp_flg = workbuf[j]; // save it for later
                workbuf[j] = DSP_FLG_MUTE|DSP_FLG_ECEN;
            }
            if (i+j == DSP_KON) {
                dsp_kon = workbuf[j]; // save it for later
                workbuf[j] = 0x00;
            }

            // take note of some values while we upload...
            if (i+j == DSP_ESA) { dsp_esa = workbuf[j]; }
            if (i+j == DSP_EDL) { dsp_edl = workbuf[j]; }
            
            apu_write(1, workbuf[j]);
            apu_write(0, i+j);
            if (!apu_waitInport(0, i+j, 500)) {
                if (apu_read(0)==0xaa) {
//              fprintf(stderr, "ingored\n");
                } else {
                    fprintf(stderr, "timeout 3\n"); return -1; 
                }
            }

            if (g_exit_now || !g_playing) { apu_reset(); return 0; }
#ifdef PROGRESS_SPINNER
            if (g_progress) {
                pspin_update();
            }
#endif
        }

    }
//  if (g_verbose) 
//      printf("\n");

    /* after receiving 128 registers, the dsp loaded will jump
     * inside the rom at address $ffc9. Once 0xAA appears in 
     * port0, the apu is ready for a new transfer. */
    if (!apu_waitInport(0, 0xaa, 500)) {
        fprintf(stderr, "timeout 4\n"); return -1; 
    }

//  fseek(fptr, OFFSET_SPCRAM, SEEK_SET);
//  fread(spcram, 64, 1, fptr);

    /* save a bunch of registers to be restored
     * later by the "bootcode" */
    bootcode[BOOT_DSP_FLG] = dsp_flg;
    bootcode[BOOT_DSP_KON] = dsp_kon;
    bootcode[BOOT_A] = spc_a;
    bootcode[BOOT_Y] = spc_y;
    bootcode[BOOT_X] = spc_x;
    bootcode[BOOT_SP] = spc_sp - 3; // save new stack pointer

    /* save address $0000 and $0001 to be restored by "bootcode" */
    fseek(fptr, OFFSET_SPCDATA, SEEK_SET);
    fread(workbuf, 2, 1, fptr);
    bootcode[0x01] = workbuf[0];
    bootcode[0x04] = workbuf[1];
    
    /* save most spc registers (0xf0 to 0xff) into bootcode to be restored
     * later */
    fseek(fptr, OFFSET_SPCDATA+0xf0, SEEK_SET);
    fread(workbuf, 0x10, 1, fptr);
    for (i=0xf0; i<=0xff; i++) {
        switch (i)
        {
            case SPC_PORT0: bootcode[BOOT_SPC_PORT0] = workbuf[i-0xf0]; break;
            case SPC_PORT1: bootcode[BOOT_SPC_PORT1] = workbuf[i-0xf0]; break;
            case SPC_PORT2: bootcode[BOOT_SPC_PORT2] = workbuf[i-0xf0]; break;
            case SPC_PORT3: bootcode[BOOT_SPC_PORT3] = workbuf[i-0xf0]; break;
            case SPC_TIMER0: bootcode[BOOT_SPC_TIMER0] = workbuf[i-0xf0]; break;
            case SPC_TIMER1: bootcode[BOOT_SPC_TIMER1] = workbuf[i-0xf0]; break;
            case SPC_TIMER2: bootcode[BOOT_SPC_TIMER2] = workbuf[i-0xf0]; break;
            case SPC_CONTROL: bootcode[BOOT_SPC_CONTROL] = workbuf[i-0xf0]; break;
            case SPC_REGADD: bootcode[BOOT_SPC_REGADD] = workbuf[i-0xf0]; break;
        }
    }
    


    /* to produce an echo effect, the dsp uses a memory region.
     * ESA: Esa * 100h becomes the lead-off address of the echo
     * region. Calculate this address... */
    echoregion = dsp_esa * 256;

    /* echo delay. The bigger the delay is, more memory is needed.
     * calculate how much memory used... */
    echosize = dsp_edl * 2048;
    if (echosize==0) { echosize = 4; }

    if (g_debug) { 
        printf("debug: echoregion: $%04x, size %d\n", echoregion, echosize);
    }

    apu_initTransfer(0x0002);
    if (g_verbose) 
        printf("Restoring spc700 memory...\n");
    
    if (g_debug) { 
        printf("debug: Sending spc memory from 0x02 to 0xef\n");
    }
    /* send the first part of the memory (0x02 to 0xef)
     * After 0xef comes spc700 registers (0xf0 to 0xff). Those
     * are taken care of by the bootcode. 0x00 and 0x01 are
     * retored by the bootcode too. */
    fseek(fptr, OFFSET_SPCDATA, SEEK_SET);
    for (j=0; j<256; j+=64)
    {
        fread(workbuf, 64, 1, fptr);
        for (i=0; i<0x40; i++) {
            if (j+i>=0xf0) { break; }
            if (j==0 && i<2) { continue; } // skip $0000 and $0001
            apu_write(1, workbuf[i]);
            apu_write(0, j+i-2);
            if (!apu_waitInport(0, j+i-2, 500)) {
                fprintf(stderr, "timeout 5\n"); return -1; 
            }
#ifdef PROGRESS_SPINNER
            if (g_progress) 
                pspin_update();
#endif
            if (g_exit_now || !g_playing) { apu_reset(); return 0; }
        }
        if (j+i>=0xf0) { break; }
    }

//  if (g_verbose) 
//      printf("\n");

    if (apu_newTransfer(0x100)) { apu_reset(); return -1; }
    
    if (g_debug) { 
        printf("debug: Sending spc memory from 0x100 to 0xffc0\n");
    }
    /* upload the external memory region data (0x100 (page 1) to 0xffbf (rom),
     * and look for an area with the same consecutive value repeated 77 times */    
    fseek(fptr, OFFSET_SPCDATA+0x100, SEEK_SET);
    bootptr = -1;
    for (i=0x100; i <= 65471; i+= 16)
    {       
        fread(workbuf, 16, 1, fptr);
        
        for (j=0; j<16; j++) {
            /* push program counter and status ward on stack */
            if ((i+j) == (0x100 +spc_sp - 0)) {
                workbuf[j] = spc_pch;
            }
            if ((i+j) == (0x100 +spc_sp - 1)) {
                workbuf[j] = spc_pcl;
            }
            if ((i+j) == (0x100 +spc_sp - 2)) {
                workbuf[j] = spc_sw;
            }
            
            if ((i > echoregion + echosize) || (i < echoregion) )
            {
                if (val==workbuf[j]) {
                    count++;
                    if (count>=77) {
                        bootptr = i+j-77;
//                      printf("nbptr: %d\n", i+j-77);
                    }
                }
                else {
                    val = workbuf[j];
                    count = 0;
                }
            }
            else
            {
                count = 0;
            }
        }
        
        if (apu_writeBytes(workbuf, 16))
        {
            fprintf(stderr, "Transfer error\n");
            return -1;
        }

        if (i % 256 == 0) {
            readcount += 256;
#ifdef PROGRESS_SPINNER
            if (g_progress) {
                pspin_update();
            }
#endif
        }
        if (g_exit_now || !g_playing) { apu_reset(); return 0; }
    }
    
//  bootptr = 0x2e47;
    if (g_debug) {  
        printf("debug: area for bootcode: $%04x (%02X)\n", bootptr, val);
    }
    
    /* we did not find an area of 77 consecutive identical byte values. */
    if (bootptr == -1) 
    {
        /* We will have to use the echo region. The region will need to be
         * at least 77 bytes... */
        if (echosize < 77) {
            fprintf(stderr, "This spc file does not have sufficient ram to be loaded");
            return -1;
        }
        else {
            /* we will use the echo region */
            bootptr = echoregion;
        }
    }

    if (g_debug) { 
        printf("debug: Sending spc memory from 0xffc0 to 0xffff\n");
    }
    /* upload the external memory area overlapping with the rom... I guess
     * if we write to those address from the SPC it really writes to this
     * memory area, but if you read you'll probably get the ROM code. Maybe
     * it's really Read/Write from the DSP point of view... TODO: Check this 
     *
     * Maybe also setting SPC_CONTROL msb bit enables this region? It's not
     * documented my manual...
     * */
    if (bootcode[BOOT_SPC_CONTROL] & 0x80) {
        fseek(fptr, OFFSET_SPCRAM, SEEK_SET);
        fread(workbuf, 64, 1, fptr);
    }
    else {
        fseek(fptr, OFFSET_SPCDATA + 65472, SEEK_SET);
        fread(workbuf, 64, 1, fptr);
    }
    
    if (apu_writeBytes(workbuf, 64)) {
        return -1;
    }

//  if (g_verbose) 
//      printf("\n");

    if (apu_newTransfer(bootptr)) { apu_reset(); return -1; }

    /* Copy our bootcode into the area we found */
    if (apu_writeBytes(bootcode, 77)) {
        fprintf(stderr, "Bootcode transfer error\n");
        return -1;
    }

    apu_endTransfer(bootptr);
    
    //i = 0;
    if (!apu_waitInport(0, 0x53, 500)) {
        fprintf(stderr, "timeout 7\n");
        return -1;
    }

    if (g_debug) {
        printf("Setting final port values $%02X $%02X $%02X $%02X\n",
                bootcode[BOOT_SPC_PORT0], bootcode[BOOT_SPC_PORT1], 
                bootcode[BOOT_SPC_PORT2], bootcode[BOOT_SPC_PORT3]);
    }

    /* Restore the ports to the value they
     * had in the .spc  (this is not done by the bootcode because
     * Port0-3 have 2 different values (The value set internally is
     * seen externaly and the value seen internally is set externally) */
    apu_write(0, bootcode[BOOT_SPC_PORT0]);
    apu_write(1, bootcode[BOOT_SPC_PORT1]);
    apu_write(2, bootcode[BOOT_SPC_PORT2]);
    apu_write(3, bootcode[BOOT_SPC_PORT3]);

    
    if (g_exit_now || !g_playing) { apu_reset(); return 0; }
    return 0;
}