Cheats: find the cheat file by CRC32.

cheats.cpp

@@ -49,8 +49,49 @@ struct CheatComp
 
 static char cheat_zip[1024] = {};
 
-void cheats_init(char *rom_path)
-{
+int find_by_crc(uint32_t romcrc)
+{
+	sprintf(cheat_zip, "%s/cheats/%s", getRootDir(), HomeDir);
+	DIR *d = opendir(cheat_zip);
+	if (!d)
+	{
+		printf("Couldn't open dir: %s\n", cheat_zip);
+		return 0;
+	}
+
+	struct dirent *de = 0;
+	while((de = readdir(d)))
+	{
+		if (de->d_type == DT_REG)
+		{
+			char *ext = strcasestr(de->d_name, ".zip");
+			if (ext && (ext - de->d_name) > 10)
+			{
+				ext -= 10;
+				if (ext[0] == '[' && ext[9] == ']')
+				{
+					uint32_t crc = 0;
+					if (sscanf(ext, "[%X].zip", &crc) == 1)
+					{
+						if (crc == romcrc)
+						{
+							strcat(cheat_zip, "/");
+							strcat(cheat_zip, de->d_name);
+							closedir(d);
+							return 1;
+						}
+					}
+				}
+			}
+		}
+	}
+
+	closedir(d);
+	return 0;
+}
+
+void cheats_init(char *rom_path, uint32_t romcrc)
+{
 	cheats.clear();
 	loaded = 0;
 	cheat_zip[0] = 0;
@@ -68,9 +109,9 @@ void cheats_init(char *rom_path)
 	{
 		memset(&_z, 0, sizeof(_z));
 
-		char *rom_name = strrchr(rom_path, '/');
-		if (!rom_name) return;
-
+		char *rom_name = strrchr(rom_path, '/');
+		if (!rom_name) return;
+
 		sprintf(cheat_zip, "%s/cheats/%s%s", getRootDir(), HomeDir, rom_name);
 		char *p = strrchr(cheat_zip, '.');
 		if (p) *p = 0;
@@ -78,11 +119,17 @@ void cheats_init(char *rom_path)
 
 		if (!mz_zip_reader_init_file(&_z, cheat_zip, 0))
 		{
-			printf("no cheat file %s\n", cheat_zip);
-			return;
+			memset(&_z, 0, sizeof(_z));
+			if (!find_by_crc(romcrc) || !mz_zip_reader_init_file(&_z, cheat_zip, 0))
+			{
+				printf("no cheat file found\n");
+				return;
+			}
 		}
 	}
 
+	printf("Using cheat file: %s\n", cheat_zip);
+
 	mz_zip_archive *z = new mz_zip_archive(_z);
 	for (size_t i = 0; i < mz_zip_reader_get_num_files(z); i++)
 	{
@@ -325,6 +372,6 @@ void cheats_toggle()
 }
 
 int cheats_loaded()
-{
+{
 	return loaded;
 }

cheats.h

@@ -1,7 +1,7 @@
 #ifndef CHEATS_H
 #define CHEATS_H
 
-void cheats_init(char *rom_path);
+void cheats_init(char *rom_path, uint32_t romcrc);
 int cheats_available();
 void cheats_scan(int mode);
 void cheats_scroll_name();

menu.cpp

@@ -1414,7 +1414,7 @@ void HandleUI(void)
 		printf("File selected: %s\n", SelectedPath);
 		user_io_store_filename(SelectedPath);
 		user_io_file_tx(SelectedPath, user_io_ext_idx(SelectedPath, fs_pFileExt) << 6 | (menusub + 1), opensave);
-		cheats_init(SelectedPath);
+		if(user_io_use_cheats()) cheats_init(SelectedPath, user_io_get_file_crc());
 		menustate = MENU_NONE1;
 		break;
 

user_io.cpp

@@ -11,7 +11,6 @@
 #include <sys/statvfs.h>
 
 #include "lib/lodepng/lodepng.h"
-
 #include "hardware.h"
 #include "osd.h"
 #include "user_io.h"
@@ -29,6 +28,7 @@
 #include "bootcore.h"
 #include "charrom.h"
 #include "scaler.h"
+#include "miniz.h"
 
 #include "support.h"
 
@@ -297,6 +297,8 @@ int user_io_get_joy_transl()
 	return joy_transl;
 }
 
+static int use_cheats = 0;
+
 static void parse_config()
 {
 	int i = 0;
@@ -362,6 +364,11 @@ static void parse_config()
 				substrcpy(s + strlen(s), p, 1);
 				OsdCoreNameSet(s);
 			}
+
+			if (p[0] == 'C')
+			{
+				use_cheats = 1;
+			}
 		}
 		i++;
 	} while (p || i<3);
@@ -1290,6 +1297,17 @@ static void send_pcolchr(const char* name, unsigned char index, int type)
 	}
 }
 
+static uint32_t file_crc;
+uint32_t user_io_get_file_crc()
+{
+	return file_crc;
+}
+
+int user_io_use_cheats()
+{
+	return use_cheats;
+}
+
 int user_io_file_tx(const char* name, unsigned char index, char opensave, char mute, char composite)
 {
 	fileTYPE f = {};
@@ -1351,6 +1369,7 @@ int user_io_file_tx(const char* name, unsigned char index, char opensave, char m
 			spi_write(buf, 512, fio_size);
 			DisableFpga();
 
+			//strip original SNES ROM header if present (not used)
 			if (bytes2send & 512)
 			{
 				bytes2send -= 512;
@@ -1358,6 +1377,9 @@ int user_io_file_tx(const char* name, unsigned char index, char opensave, char m
 			}
 		}
 
+		file_crc = 0;
+		uint32_t skip = bytes2send & 0x3FF; // skip possible header up to 1023 bytes
+
 		while (bytes2send)
 		{
 			printf(".");
@@ -1372,8 +1394,16 @@ int user_io_file_tx(const char* name, unsigned char index, char opensave, char m
 			DisableFpga();
 
 			bytes2send -= chunk;
+
+			if (skip >= chunk) skip -= chunk;
+			else
+			{
+				file_crc = crc32(file_crc, buf + skip, chunk - skip);
+				skip = 0;
+			}
 		}
 		printf("\n");
+		printf("CRC32: %08X\n", file_crc);
 	}
 
 	FileClose(&f);

user_io.h

@@ -188,6 +188,7 @@ void user_io_serial_tx(char *, uint16_t);
 char *user_io_8bit_get_string(char);
 uint32_t user_io_8bit_set_status(uint32_t, uint32_t);
 int user_io_file_tx(const char* name, unsigned char index = 0, char opensave = 0, char mute = 0, char composite = 0);
+uint32_t user_io_get_file_crc();
 int  user_io_file_mount(char *name, unsigned char index = 0, char pre = 0);
 char user_io_serial_status(serial_status_t *, uint8_t);
 char *user_io_get_core_name();
@@ -251,5 +252,6 @@ void set_volume(int cmd);
 int  get_volume();
 
 void user_io_store_filename(char *filename);
+int user_io_use_cheats();
 
 #endif // USER_IO_H