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[picodrive.git] / Pico / Cart.c

// This is part of Pico Library\r
\r
// (c) Copyright 2004 Dave, All rights reserved.\r
// (c) Copyright 2006 notaz, All rights reserved.\r
// Free for non-commercial use.\r
\r
// For commercial use, separate licencing terms must be obtained.\r
\r
\r
#include "PicoInt.h"\r
#include "../zlib/zlib.h"\r
#include "../unzip/unzip.h"\r
#include "../unzip/unzip_stream.h"\r
\r
static char *rom_exts[] = { "bin", "gen", "smd", "iso" };\r
\r
\r
pm_file *pm_open(const char *path)\r
{\r
  pm_file *file = NULL;\r
  const char *ext;\r
  FILE *f;\r
\r
  if (path == NULL) return NULL;\r
\r
  if (strlen(path) < 5) ext = NULL; // no ext\r
  else ext = path + strlen(path) - 3;\r
\r
  if (ext && strcasecmp(ext, "zip") == 0)\r
  {\r
    struct zipent *zipentry;\r
    gzFile gzf = NULL;\r
    ZIP *zipfile;\r
    int i;\r
\r
    zipfile = openzip(path);\r
\r
    if (zipfile != NULL)\r
    {\r
      /* search for suitable file (right extension or large enough file) */\r
      while ((zipentry = readzip(zipfile)) != NULL)\r
      {\r
        if (zipentry->uncompressed_size >= 128*1024) goto found_rom_zip;\r
        if (strlen(zipentry->name) < 5) continue;\r
\r
        ext = zipentry->name+strlen(zipentry->name)-3;\r
        for (i = 0; i < sizeof(rom_exts)/sizeof(rom_exts[0]); i++)\r
          if (!strcasecmp(ext, rom_exts[i]) == 0) goto found_rom_zip;\r
      }\r
\r
      /* zipfile given, but nothing found suitable for us inside */\r
      goto zip_failed;\r
\r
found_rom_zip:\r
      /* try to convert to gzip stream, so we could use standard gzio functions from zlib */\r
      gzf = zip2gz(zipfile, zipentry);\r
      if (gzf == NULL)  goto zip_failed;\r
\r
      file = malloc(sizeof(*file));\r
      if (file == NULL) goto zip_failed;\r
      file->file  = zipfile;\r
      file->param = gzf;\r
      file->size  = zipentry->uncompressed_size;\r
      file->type  = PMT_ZIP;\r
      return file;\r
\r
zip_failed:\r
      if (gzf) {\r
        gzclose(gzf);\r
        zipfile->fp = NULL; // gzclose() closed it\r
      }\r
      closezip(zipfile);\r
      return NULL;\r
    }\r
  }\r
\r
  /* not a zip, treat as uncompressed file */\r
  f = fopen(path, "rb");\r
  if (f == NULL) return NULL;\r
\r
  file = malloc(sizeof(*file));\r
  if (file == NULL) {\r
    fclose(f);\r
    return NULL;\r
  }\r
  fseek(f, 0, SEEK_END);\r
  file->file  = f;\r
  file->param = NULL;\r
  file->size  = ftell(f);\r
  file->type  = PMT_UNCOMPRESSED;\r
  fseek(f, 0, SEEK_SET);\r
  return file;\r
}\r
\r
size_t pm_read(void *ptr, size_t bytes, pm_file *stream)\r
{\r
  int ret;\r
\r
  if (stream->type == PMT_UNCOMPRESSED)\r
  {\r
    ret = fread(ptr, 1, bytes, stream->file);\r
  }\r
  else if (stream->type == PMT_ZIP)\r
  {\r
    gzFile gf = stream->param;\r
    int err;\r
    ret = gzread(gf, ptr, bytes);\r
    err = gzerror2(gf);\r
    if (ret > 0 && (err == Z_DATA_ERROR || err == Z_STREAM_END))\r
      /* we must reset stream pointer or else next seek/read fails */\r
      gzrewind(gf);\r
  }\r
  else\r
    ret = 0;\r
\r
  return ret;\r
}\r
\r
int pm_seek(pm_file *stream, long offset, int whence)\r
{\r
  if (stream->type == PMT_UNCOMPRESSED)\r
  {\r
    return fseek(stream->file, offset, whence);\r
  }\r
  else if (stream->type == PMT_ZIP)\r
  {\r
    return gzseek((gzFile) stream->param, offset, whence);\r
  }\r
  else\r
    return -1;\r
}\r
\r
int pm_close(pm_file *fp)\r
{\r
  int ret = 0;\r
\r
  if (fp == NULL) return EOF;\r
\r
  if (fp->type == PMT_UNCOMPRESSED)\r
  {\r
    fclose(fp->file);\r
  }\r
  else if (fp->type == PMT_ZIP)\r
  {\r
    ZIP *zipfile = fp->file;\r
    gzclose((gzFile) fp->param);\r
    zipfile->fp = NULL; // gzclose() closed it\r
    closezip(zipfile);\r
  }\r
  else\r
    ret = EOF;\r
\r
  free(fp);\r
  return ret;\r
}\r
\r
\r
void Byteswap(unsigned char *data,int len)\r
{\r
  int i=0;\r
\r
  if (len<2) return; // Too short\r
\r
  do\r
  {\r
    unsigned short *pd=(unsigned short *)(data+i);\r
    int value=*pd; // Get 2 bytes\r
\r
    value=(value<<8)|(value>>8); // Byteswap it\r
    *pd=(unsigned short)value; // Put 2b ytes\r
    i+=2;\r
  }\r
  while (i+2<=len);\r
}\r
\r
// Interleve a 16k block and byteswap\r
static int InterleveBlock(unsigned char *dest,unsigned char *src)\r
{\r
  int i=0;\r
  for (i=0;i<0x2000;i++) dest[(i<<1)  ]=src[       i]; // Odd\r
  for (i=0;i<0x2000;i++) dest[(i<<1)+1]=src[0x2000+i]; // Even\r
  return 0;\r
}\r
\r
// Decode a SMD file\r
static int DecodeSmd(unsigned char *data,int len)\r
{\r
  unsigned char *temp=NULL;\r
  int i=0;\r
\r
  temp=(unsigned char *)malloc(0x4000);\r
  if (temp==NULL) return 1;\r
  memset(temp,0,0x4000);\r
\r
  // Interleve each 16k block and shift down by 0x200:\r
  for (i=0; i+0x4200<=len; i+=0x4000)\r
  {\r
    InterleveBlock(temp,data+0x200+i); // Interleve 16k to temporary buffer\r
    memcpy(data+i,temp,0x4000); // Copy back in\r
  }\r
\r
  free(temp);\r
  return 0;\r
}\r
\r
static unsigned char *cd_realloc(void *old, int filesize)\r
{\r
  unsigned char *rom;\r
  dprintf("sizeof(mcd_state): %i", sizeof(mcd_state));\r
  rom=realloc(old, sizeof(mcd_state));\r
  if (rom) memset(rom+0x20000, 0, sizeof(mcd_state)-0x20000);\r
  return rom;\r
}\r
\r
static unsigned char *PicoCartAlloc(int filesize)\r
{\r
  int alloc_size;\r
  unsigned char *rom;\r
\r
  if (PicoMCD & 1) return cd_realloc(NULL, filesize);\r
\r
  alloc_size=filesize+0x7ffff;\r
  if((filesize&0x3fff)==0x200) alloc_size-=0x200;\r
  alloc_size&=~0x7ffff; // use alloc size of multiples of 512K, so that memhandlers could be set up more efficiently\r
  if((filesize&0x3fff)==0x200) alloc_size+=0x200;\r
  else if(alloc_size-filesize < 4) alloc_size+=4; // padding for out-of-bound exec protection\r
  //dprintf("alloc_size: %x\n",  alloc_size);\r
\r
  // Allocate space for the rom plus padding\r
  rom=(unsigned char *)malloc(alloc_size);\r
  if(rom) memset(rom+alloc_size-0x80000,0,0x80000);\r
  return rom;\r
}\r
\r
int PicoCartLoad(pm_file *f,unsigned char **prom,unsigned int *psize)\r
{\r
  unsigned char *rom=NULL; int size;\r
  if (f==NULL) return 1;\r
\r
  size=f->size;\r
  if (size <= 0) return 1;\r
  size=(size+3)&~3; // Round up to a multiple of 4\r
\r
  // Allocate space for the rom plus padding\r
  rom=PicoCartAlloc(size);\r
  if (rom==NULL) return 1; // { fclose(f); return 1; }\r
\r
  pm_read(rom,size,f); // Load up the rom\r
\r
  // maybe we are loading MegaCD BIOS?\r
  if (!(PicoMCD&1) && size == 0x20000 && (!strncmp((char *)rom+0x124, "BOOT", 4) || !strncmp((char *)rom+0x128, "BOOT", 4))) {\r
    PicoMCD |= 1;\r
    rom = cd_realloc(rom, size);\r
  }\r
\r
  // Check for SMD:\r
  if ((size&0x3fff)==0x200) { DecodeSmd(rom,size); size-=0x200; } // Decode and byteswap SMD\r
  else Byteswap(rom,size); // Just byteswap\r
\r
  if (prom)  *prom=rom;\r
  if (psize) *psize=size;\r
\r
  return 0;\r
}\r
\r
// Insert/remove a cartridge:\r
int PicoCartInsert(unsigned char *rom,unsigned int romsize)\r
{\r
  // notaz: add a 68k "jump one op back" opcode to the end of ROM.\r
  // This will hang the emu, but will prevent nasty crashes.\r
  // note: 4 bytes are padded to every ROM\r
  if(rom != NULL)\r
    *(unsigned long *)(rom+romsize) = 0xFFFE4EFA; // 4EFA FFFE byteswapped\r
\r
  SRam.resize=1;\r
  Pico.rom=rom;\r
  Pico.romsize=romsize;\r
\r
  return PicoReset(1);\r
}\r
\r
int PicoUnloadCart(unsigned char* romdata)\r
{\r
  free(romdata);\r
  return 0;\r
}\r
\r