initial import

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@2 be3aeb3a-fb24-0410-a615-afba39da0efa

Pico/Cart.c

@@ -0,0 +1,197 @@
+// This is part of Pico Library
+
+// (c) Copyright 2004 Dave, All rights reserved.
+// (c) Copyright 2006 notaz, All rights reserved.
+// Free for non-commercial use.
+
+// For commercial use, separate licencing terms must be obtained.
+
+
+#include "PicoInt.h"
+
+void Byteswap(unsigned char *data,int len)
+{
+  int i=0;
+
+  if (len<2) return; // Too short
+
+  do
+  {
+    unsigned short *pd=(unsigned short *)(data+i);
+    int value=*pd; // Get 2 bytes
+
+    value=(value<<8)|(value>>8); // Byteswap it
+    *pd=(unsigned short)value; // Put 2b ytes
+    i+=2;
+  }
+  while (i+2<=len);
+}
+
+// Interleve a 16k block and byteswap
+static int InterleveBlock(unsigned char *dest,unsigned char *src)
+{
+  int i=0;
+  for (i=0;i<0x2000;i++) dest[(i<<1)  ]=src[       i]; // Odd
+  for (i=0;i<0x2000;i++) dest[(i<<1)+1]=src[0x2000+i]; // Even
+  return 0;
+}
+
+// Decode a SMD file
+static int DecodeSmd(unsigned char *data,int len)
+{
+  unsigned char *temp=NULL;
+  int i=0;
+
+  temp=(unsigned char *)malloc(0x4000);
+  if (temp==NULL) return 1;
+  memset(temp,0,0x4000);
+
+  // Interleve each 16k block and shift down by 0x200:
+  for (i=0; i+0x4200<=len; i+=0x4000)
+  {
+    InterleveBlock(temp,data+0x200+i); // Interleve 16k to temporary buffer
+    memcpy(data+i,temp,0x4000); // Copy back in
+  }
+
+  free(temp);
+  return 0;
+}
+
+static unsigned char *PicoCartAlloc(int filesize)
+{
+  int alloc_size;
+  unsigned char *rom;
+
+  if (PicoMCD & 1) {
+    dprintf("sizeof(mcd_state): %i", sizeof(mcd_state));
+    if (filesize > 0x20000) return NULL; // invalid BIOS
+    rom=(unsigned char *)malloc(sizeof(mcd_state));
+    if (rom) memset(rom, 0, sizeof(mcd_state));
+    return rom;
+  }
+
+  alloc_size=filesize+0x7ffff;
+  if((filesize&0x3fff)==0x200) alloc_size-=0x200;
+  alloc_size&=~0x7ffff; // use alloc size of multiples of 512K, so that memhandlers could be set up more efficiently
+  if((filesize&0x3fff)==0x200) alloc_size+=0x200;
+  else if(alloc_size-filesize < 4) alloc_size+=4; // padding for out-of-bound exec protection
+  //dprintf("alloc_size: %x\n",  alloc_size);
+
+  // Allocate space for the rom plus padding
+  rom=(unsigned char *)malloc(alloc_size);
+  if(rom) memset(rom+alloc_size-0x80000,0,0x80000);
+  return rom;
+}
+
+int PicoCartLoad(FILE *f,unsigned char **prom,unsigned int *psize)
+{
+  unsigned char *rom=NULL; int size;
+  if (f==NULL) return 1;
+
+  fseek(f,0,SEEK_END); size=ftell(f); fseek(f,0,SEEK_SET);
+  if (size <= 0) return 1;
+  if (PicoMCD & 1) {
+    if (size > 0x20000) return 1; // invalid BIOS
+    size = 0xe0000;
+  } else {
+    size=(size+3)&~3; // Round up to a multiple of 4
+  }
+
+  // Allocate space for the rom plus padding
+  rom=PicoCartAlloc(size);
+  if (rom==NULL) return 1; // { fclose(f); return 1; }
+
+  fread(rom,1,size,f); // Load up the rom
+  // fclose(f); // this is confusing. From now on, caller should close it, because it opened this.
+
+  // Check for SMD:
+  if ((size&0x3fff)==0x200) { DecodeSmd(rom,size); size-=0x200; } // Decode and byteswap SMD
+  else Byteswap(rom,size); // Just byteswap
+
+  if (prom)  *prom=rom;
+  if (psize) *psize=size;
+
+  return 0;
+}
+
+// Insert/remove a cartridge:
+int PicoCartInsert(unsigned char *rom,unsigned int romsize)
+{
+  // notaz: add a 68k "jump one op back" opcode to the end of ROM.
+  // This will hang the emu, but will prevent nasty crashes.
+  // note: 4 bytes are padded to every ROM
+  if(rom != NULL)
+    *(unsigned long *)(rom+romsize) = 0xFFFE4EFA; // 4EFA FFFE byteswapped
+
+  SRam.resize=1;
+  Pico.rom=rom;
+  Pico.romsize=romsize;
+
+  return PicoReset(1);
+}
+
+int PicoUnloadCart(unsigned char* romdata)
+{
+  free(romdata);
+  return 0;
+}
+
+
+#ifdef _UNZIP_SUPPORT
+
+// notaz
+#include "../unzip/unzip.h"
+
+// nearly same as PicoCartLoad, but works with zipfiles
+int CartLoadZip(const char *fname, unsigned char **prom, unsigned int *psize)
+{
+	unsigned char *rom=0;
+	struct zipent* zipentry;
+	int size;
+	ZIP *zipfile = openzip(fname);
+
+	if(!zipfile) return 1;
+
+	// find first bin or smd
+	while((zipentry = readzip(zipfile)) != 0)
+	{
+		char *ext;
+		if(strlen(zipentry->name) < 5) continue;
+		ext = zipentry->name+strlen(zipentry->name)-4;
+
+		if(!strcasecmp(ext, ".bin") || !strcasecmp(ext, ".smd") || !strcasecmp(ext, ".gen")) break;
+	}
+
+	if(!zipentry) {
+		closezip(zipfile);
+		return 4; // no roms
+	}
+
+	size = zipentry->uncompressed_size;
+
+	size=(size+3)&~3; // Round up to a multiple of 4
+
+	// Allocate space for the rom plus padding
+	rom=PicoCartAlloc(size);
+	if (rom==NULL) { closezip(zipfile); return 2; }
+
+	if(readuncompresszip(zipfile, zipentry, (char *)rom) != 0) {
+		free(rom);
+		rom = 0;
+		closezip(zipfile);
+		return 5; // unzip failed
+	}
+
+	closezip(zipfile);
+
+	// Check for SMD:
+	if ((size&0x3fff)==0x200) { DecodeSmd(rom,size); size-=0x200; } // Decode and byteswap SMD
+	else Byteswap(rom,size); // Just byteswap
+
+	if (prom)  *prom=rom;
+	if (psize) *psize=size;
+
+	return 0;
+}
+
+#endif