Updated IPS code. Now supports RLE, should fix problems if the ROM is expanded, and automatically view the ROM with a header.

2003-08-18 20:13:58 +00:00
parent c324ad0ee7
commit 1cca98563b
6 changed files with 142 additions and 170 deletions
--- a/zsnes/src/patch.c
+++ b/zsnes/src/patch.c
@@ -0,0 +1,123 @@
+/*
+Copyright (C) 2003 ZSNES Team ( zsknight@zsnes.com / _demo_@zsnes.com )
+
+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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <stdio.h>
+
+extern int maxromspace;
+extern int curromspace;
+extern int NumofBytes;
+extern int NumofBanks;
+extern unsigned int *romdata;
+extern unsigned char IPSPatched;
+
+char *patchfile;
+
+void PatchUsingIPS()
+{
+  unsigned char *ROM = (unsigned char *)romdata;
+  int location = 0, length = 0;
+  
+  IPSPatched = 0;
+  
+  FILE *fp = 0;
+  fp = fopen(patchfile, "rb");
+  if (!fp) { return; }
+  
+  //Yup, it's goto! :)
+  //See 'IPSDone:' for explanation
+  if (fgetc(fp) != 'P') { goto IPSDone; }
+  if (fgetc(fp) != 'A') { goto IPSDone; }
+  if (fgetc(fp) != 'T') { goto IPSDone; }
+  if (fgetc(fp) != 'C') { goto IPSDone; }
+  if (fgetc(fp) != 'H') { goto IPSDone; }
+
+  while (!feof(fp))
+  {
+    //Location is a 3 byte value (max 16MB)
+    int inloc = (fgetc(fp) << 16) | (fgetc(fp) << 8) | fgetc(fp);
+
+    if (inloc == 0x454f46) //EOF
+    { 
+      break;
+    }
+
+    //We assume all IPS files are for ROMs with headers
+    location = inloc - 512;
+
+    //Length is a 2 byte value (max 64KB)
+    length = (fgetc(fp) << 8) | fgetc(fp);
+
+    if (length) // Not RLE 
+    {
+      int i;
+      for (i = 0; i < length; i++, location++)
+      {
+        if (location >= 0)
+        {
+          if (location >= maxromspace) { goto IPSDone; }
+          ROM[location] = (unsigned char)fgetc(fp);
+        }
+        else
+        {
+          fgetc(fp); //Need to skip the bytes that write to header
+        }
+      }
+    }
+    else //RLE
+    {
+      int i;
+      unsigned char newVal;
+      length = (fgetc(fp) << 8) | fgetc(fp); 
+      newVal = (unsigned char)fgetc(fp);
+      for (i = 0; i < length; i++, location++)
+      {
+        if (location >= 0)
+        {
+          if (location >= maxromspace) { goto IPSDone; }
+          ROM[location] = newVal;
+        }
+      }
+    }
+  }
+  
+  //We use gotos to break out of the nested loops,
+  //as well as a simple way to check for 'PATCH' in
+  //some cases like this one, goto is the way to go.
+  IPSDone:
+  
+  fclose(fp);
+  IPSPatched = 1;
+  
+  //Adjust size values if the ROM was expanded
+  if (location > curromspace  && location <= maxromspace)
+  {
+    curromspace = location;
+    NumofBytes = location;
+    NumofBanks = NumofBytes/32768;
+  }
+
+  /*
+  //Write out patched ROM
+  fp = fopen("zsnes.rom", "wb");
+  if (!fp) { asm volatile("int $3"); }
+  fwrite(ROM, 1, curromspace, fp);
+  fclose(fp);
+  */
+}  
+