Files
Main_MiSTer/support/snes/snes.cpp

432 lines
12 KiB
C++

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <limits.h>
#include <glob.h>
#include "../../file_io.h"
#include "../../user_io.h"
#include "../../spi.h"
static uint8_t hdr[512];
enum HeaderField {
CartName = 0x00,
Mapper = 0x15,
RomType = 0x16,
RomSize = 0x17,
RamSize = 0x18,
CartRegion = 0x19,
Company = 0x1a,
Version = 0x1b,
Complement = 0x1c, //inverse checksum
Checksum = 0x1e,
ResetVector = 0x3c,
};
static uint32_t score_header(const uint8_t *data, uint32_t size, uint32_t addr)
{
if (size < addr + 64) return 0; //image too small to contain header at this location?
int score = 0;
uint16_t resetvector = data[addr + ResetVector] | (data[addr + ResetVector + 1] << 8);
uint16_t checksum = data[addr + Checksum] | (data[addr + Checksum + 1] << 8);
uint16_t complement = data[addr + Complement] | (data[addr + Complement + 1] << 8);
uint8_t resetop = data[(addr & ~0x7fff) | (resetvector & 0x7fff)]; //first opcode executed upon reset
uint8_t mapper = data[addr + Mapper] & ~0x10; //mask off irrelevent FastROM-capable bit
//$00:[0000-7fff] contains uninitialized RAM and MMIO.
//reset vector must point to ROM at $00:[8000-ffff] to be considered valid.
if (resetvector < 0x8000) return 0;
//some images duplicate the header in multiple locations, and others have completely
//invalid header information that cannot be relied upon.
//below code will analyze the first opcode executed at the specified reset vector to
//determine the probability that this is the correct header.
//most likely opcodes
if (resetop == 0x78 //sei
|| resetop == 0x18 //clc (clc; xce)
|| resetop == 0x38 //sec (sec; xce)
|| resetop == 0x9c //stz $nnnn (stz $4200)
|| resetop == 0x4c //jmp $nnnn
|| resetop == 0x5c //jml $nnnnnn
) score += 8;
//plausible opcodes
if (resetop == 0xc2 //rep #$nn
|| resetop == 0xe2 //sep #$nn
|| resetop == 0xad //lda $nnnn
|| resetop == 0xae //ldx $nnnn
|| resetop == 0xac //ldy $nnnn
|| resetop == 0xaf //lda $nnnnnn
|| resetop == 0xa9 //lda #$nn
|| resetop == 0xa2 //ldx #$nn
|| resetop == 0xa0 //ldy #$nn
|| resetop == 0x20 //jsr $nnnn
|| resetop == 0x22 //jsl $nnnnnn
) score += 4;
//implausible opcodes
if (resetop == 0x40 //rti
|| resetop == 0x60 //rts
|| resetop == 0x6b //rtl
|| resetop == 0xcd //cmp $nnnn
|| resetop == 0xec //cpx $nnnn
|| resetop == 0xcc //cpy $nnnn
) score -= 4;
//least likely opcodes
if (resetop == 0x00 //brk #$nn
|| resetop == 0x02 //cop #$nn
|| resetop == 0xdb //stp
|| resetop == 0x42 //wdm
|| resetop == 0xff //sbc $nnnnnn,x
) score -= 8;
//at times, both the header and reset vector's first opcode will match ...
//fallback and rely on info validity in these cases to determine more likely header.
//a valid checksum is the biggest indicator of a valid header.
if ((checksum + complement) == 0xffff && (checksum != 0) && (complement != 0)) score += 4;
if (addr == 0x007fc0 && mapper == 0x20) score += 2; //0x20 is usually LoROM
if (addr == 0x00ffc0 && mapper == 0x21) score += 2; //0x21 is usually HiROM
if (addr == 0x007fc0 && mapper == 0x22) score += 2; //0x22 is usually SDD1
if (addr == 0x40ffc0 && mapper == 0x25) score += 2; //0x25 is usually ExHiROM
if (data[addr + Company] == 0x33) score += 2; //0x33 indicates extended header
if (data[addr + RomType] < 0x08) score++;
if (data[addr + RomSize] < 0x10) score++;
if (data[addr + RamSize] < 0x08) score++;
if (data[addr + CartRegion] < 14) score++;
if (score < 0) score = 0;
return score;
}
static uint32_t find_header(const uint8_t *data, uint32_t size)
{
uint32_t score_lo = score_header(data, size, 0x007fc0);
uint32_t score_hi = score_header(data, size, 0x00ffc0);
uint32_t score_ex = score_header(data, size, 0x40ffc0);
if (score_ex) score_ex += 4; //favor ExHiROM on images > 32mbits
if (score_lo >= score_hi && score_lo >= score_ex)
{
return score_lo ? 0x007fc0 : 0;
}
else if (score_hi >= score_ex)
{
return score_hi ? 0x00ffc0 : 0;
}
return score_ex ? 0x40ffc0 : 0;
}
uint8_t* snes_get_header(fileTYPE *f)
{
memset(hdr, 0, sizeof(hdr));
uint32_t size = f->size;
uint8_t *prebuf = (uint8_t*)malloc(size);
if (prebuf)
{
FileSeekLBA(f, 0);
if (FileReadAdv(f, prebuf, size))
{
uint8_t *buf = prebuf;
if (size & 512)
{
buf += 512;
size -= 512;
}
*(uint32_t*)(&hdr[8]) = size;
bool is_bsx_bios = false;
if (!memcmp(buf+0x7FC0, "Satellaview BS-X ", 21)) {
is_bsx_bios = true;
}
uint32_t addr = find_header(buf, size);
if (addr)
{
uint8_t ramsz = buf[addr + RamSize];
if (ramsz >= 0x08) ramsz = 0;
//re-calc rom size
uint8_t romsz = 15;
size--;
if (!(size & 0xFF000000))
{
while (!(size & 0x1000000))
{
romsz--;
size <<= 1;
}
}
bool has_bsx_slot = false;
if (buf[addr - 14] == 'Z' && buf[addr - 11] == 'J' &&
((buf[addr - 13] >= 'A' && buf[addr - 13] <= 'Z') || (buf[addr - 13] >= '0' && buf[addr - 13] <= '9')) &&
(buf[addr + Company] == 0x33 || (buf[addr - 10] == 0x00 && buf[addr - 4] == 0x00)) ) {
has_bsx_slot = true;
}
//Rom type: 0-Low, 1-High, 2-ExHigh, 3-SpecialLoRom
hdr[1] = (addr == 0x00ffc0) ? 1 :
(addr == 0x40ffc0) ? 2 :
has_bsx_slot ? 3 :
0;
//BSX 3
if (is_bsx_bios) {
hdr[1] = 0x30;
}
else {
//DSPn types 8..B
if (buf[addr + Mapper] == 0x20 && buf[addr + RomType] == 0x03)
{ //DSP1
hdr[1] |= 0x84;
}
else if (buf[addr + Mapper] == 0x21 && buf[addr + RomType] == 0x03)
{ //DSP1B
hdr[1] |= 0x80;
}
else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0x05 && buf[addr + Company] != 0xb2)
{ //DSP1B
hdr[1] |= 0x80;
}
else if (buf[addr + Mapper] == 0x31 && (buf[addr + RomType] == 0x03 || buf[addr + RomType] == 0x05))
{ //DSP1B
hdr[1] |= 0x80;
}
else if (buf[addr + Mapper] == 0x20 && buf[addr + RomType] == 0x05)
{ //DSP2
hdr[1] |= 0x90;
}
else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0x05 && buf[addr + Company] == 0xb2)
{ //DSP3
hdr[1] |= 0xA0;
}
else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0x03)
{ //DSP4
hdr[1] |= 0xB0;
}
else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0xf6)
{ //ST010
hdr[1] |= 0x88;
ramsz = 1;
if (buf[addr + RomSize] < 10) hdr[1] |= 0x20; // ST011
}
else if (buf[addr + Mapper] == 0x30 && buf[addr + RomType] == 0x25)
{ //OBC1
hdr[1] |= 0xC0;
}
if (buf[addr + Mapper] == 0x3a && (buf[addr + RomType] == 0xf5 || buf[addr + RomType] == 0xf9)) {
//SPC7110
hdr[1] |= 0xD0;
if (buf[addr + RomType] == 0xf9) hdr[1] |= 0x08; // with RTC
}
if (buf[addr + Mapper] == 0x35 && buf[addr + RomType] == 0x55)
{
//S-RTC (+ExHigh)
hdr[1] |= 0x08;
}
//CX4 4
if (buf[addr + Mapper] == 0x20 && buf[addr + RomType] == 0xf3)
{
hdr[1] |= 0x40;
}
//SDD1 5
if (buf[addr + Mapper] == 0x32 && (buf[addr + RomType] == 0x43 || buf[addr + RomType] == 0x45))
{
if (romsz < 14) hdr[1] |= 0x50; // except Star Ocean un-SDD1
}
//SA1 6
if (buf[addr + Mapper] == 0x23 && (buf[addr + RomType] == 0x32 || buf[addr + RomType] == 0x34 || buf[addr + RomType] == 0x35))
{
hdr[1] |= 0x60;
}
//GSU 7
if (buf[addr + Mapper] == 0x20 && (buf[addr + RomType] == 0x13 || buf[addr + RomType] == 0x14 || buf[addr + RomType] == 0x15 || buf[addr + RomType] == 0x1a))
{
ramsz = buf[addr - 3];
if (ramsz == 0xFF) ramsz = 5; //StarFox
if (ramsz > 6) ramsz = 6;
hdr[1] |= 0x70;
}
//1..2,E..F - reserved for other mappers.
}
hdr[2] = 0;
//PAL Regions
if ((buf[addr + CartRegion] >= 0x02 && buf[addr + CartRegion] <= 0x0C) || buf[addr + CartRegion] == 0x11)
{
hdr[3] |= 1;
}
hdr[0] = (ramsz << 4) | romsz;
printf("Size from header: 0x%X, calculated size: 0x%X\n", buf[addr + RomSize], romsz);
}
*(uint32_t*)(&hdr[4]) = addr;
}
FileSeekLBA(f, 0);
free(prebuf);
}
return hdr;
}
void snes_patch_bs_header(fileTYPE *f, uint8_t *buf)
{
if ((f->offset == 0x008000 && (buf[0xFD8] == 0x20 || buf[0xFD8] == 0x30)) ||
(f->offset == 0x010000 && (buf[0xFD8] == 0x21 || buf[0xFD8] == 0x31)))
{
if (buf[0xFD0] == 0xF0 || (buf[0xFD1] == 0xFF && buf[0xFD2] == 0xFF && buf[0xFD3] == 0xFF))
{
printf("SNES: Patch bad BS header: offset %04X, bad value %02X %02X %02X %02X\n", 0x7FD0 | (f->offset == 0x008000 ? 0x0000 : 0x8000), buf[0xFD0], buf[0xFD1], buf[0xFD2], buf[0xFD3]);
buf[0xFD3] = 0x00;
buf[0xFD2] = 0x00;
buf[0xFD1] = 0x00;
buf[0xFD0] = f->size <= 256 * 1024 ? 0x03 :
f->size <= 512 * 1024 ? 0x0F :
0xFF;
}
if (buf[0xFD5] >= 0x80)
{
printf("SNES: Patch bad BS header: offset %04X, bad value %02X %02X\n", 0x7FD4 | (f->offset == 0x008000 ? 0x0000 : 0x8000), buf[0xFD4], buf[0xFD5]);
buf[0xFD5] = 0xFF;
buf[0xFD4] = 0xFF;
}
if (buf[0xFDA] != 0x33)
{
printf("SNES: Patch bad BS header: offset %04X, bad value %02X\n", 0x7FDA | (f->offset == 0x008000 ? 0x0000 : 0x8000), buf[0xFDA]);
buf[0xFDA] = 0x33;
}
}
}
////////////// MSU /////////////
#define MSU_CD_SET 1
#define MSU_AUDIO_TRACK_MOUNTED 2
#define MSU_DATA_BASE 3
static char snes_romFileName[1024] = {};
static char SelectedPath[1024] = {};
static uint8_t buf[1024];
static char has_cd = 0;
static fileTYPE f_audio = {};
static void msu_send_command(uint64_t cmd)
{
spi_uio_cmd_cont(UIO_CD_SET);
spi_w((cmd >> 00) & 0xFFFF);
spi_w((cmd >> 16) & 0xFFFF);
spi_w((cmd >> 32) & 0xFFFF);
DisableIO();
}
static int msu_send_data(fileTYPE *f, int idx)
{
int chunk = sizeof(buf);
memset(buf, 0, chunk);
if (f->size) FileReadAdv(f, buf, chunk);
user_io_set_index(idx);
user_io_set_download(1);
user_io_file_tx_data(buf, chunk);
user_io_set_download(0);
return 1;
}
void snes_msu_init(const char* name)
{
static fileTYPE f = {};
FileClose(&f_audio);
memset(snes_romFileName, 0, 1024);
int extSize = strlen(strrchr(name, '.'));
strncpy(snes_romFileName, name, strlen(name) - extSize);
printf("MSU: Rom named '%s' initialised\n", name);
snprintf(SelectedPath, sizeof(SelectedPath), "%s.msu", snes_romFileName);
has_cd = FileOpen(&f, SelectedPath) ? 1 : 0;
uint32_t size = f.size;
FileClose(&f);
printf("MSU: enable cd: %d\n", has_cd);
if (size && size < 0x1F200000)
{
msu_send_command((0x20600000ULL << 16) | MSU_DATA_BASE);
user_io_file_tx(SelectedPath, 3, 0, 0, 0, 0x20600000);
}
msu_send_command((has_cd << 15) | MSU_CD_SET);
}
void snes_poll(void)
{
static uint8_t last_req = 255;
if (!has_cd) return;
// Detect incoming command via CD_GET (which we are repurposing for MSU1)
uint8_t req = spi_uio_cmd_cont(UIO_CD_GET);
if (req != last_req)
{
last_req = req;
uint16_t command = spi_w(0);
uint32_t data = spi_w(0);
data = (spi_w(0) << 16) | data;
DisableIO();
switch(command)
{
case 0xFF:
printf("MSU: request to reset\n");
break;
case 0x35:
snprintf(SelectedPath, sizeof(SelectedPath), "%s-%d.pcm", snes_romFileName, data);
printf("MSU: New track selected: %s\n", SelectedPath);
FileOpen(&f_audio, SelectedPath);
printf(f_audio.size ? "MSU: Track mounted\n" : "MSU: Track not found!\n");
msu_send_command((f_audio.size << 16) | MSU_AUDIO_TRACK_MOUNTED);
break;
case 0x36:
printf("MSU: Jump to offset: 0x%X\n", data * 1024);
FileSeek(&f_audio, data * 1024, SEEK_SET);
// fallthrough
case 0x34:
// Next sector requested
msu_send_data(&f_audio, 2);
break;
}
}
else
{
DisableIO();
}
}