Difference between revisions of "Ocarina of time"

Revision as of 21:47, 19 September 2012

Ocarina of time saves are still a tad unknown however thanks to spinout i have this:

Info

The Ocarina of Time save file consists of a simple 32 byte long header, and six 5200 byte long game files, in the order 1,2,3/1,2,3. The header can be freely edited. The individual game files cannot however, as the game will reject them if they've been modified, unless the checksum is manually recalculated.

File Header

Game Data

After the file header, there are 6 different game files

RAM Offsets

The save data format seems to match up to a portion of ram in game. Therefore, it's possible to determine what the values stored in the save file do by peeking into the RAM in-game. You can also use this table, along with the following table, to generate cheat codes. Simply take the appropriate offset for your game (ex. 1.0 U, 11A5D0), take an offset from the following table (ex. Respawn Point, 0x0002), and add them together (11A5D2). Then prefix it with either 80 (modify 1 byte) or 81 (modify 2 bytes), and assign a value to it (ex. 8111A5D2 0000)

Checksum

Each segment of game data has a 16 bit checksum at offset 0x1352. It is generated by adding all previous 0x9A9 shorts together (overflowing to 0 when 0xFFFF is reached).

Game Data Format

C structs/functions

Beware of endianess! Big endian (N64 native) assumed.

#define	LINK_ADULT	0
#define LINK_CHILD	1

typedef struct
{
    uint32_t	respawn_exit_n;	/* 0x0004 */
    uint32_t	age;		/* 0x0008 */
    uint8_t	__pad_00[0x014];/* 0x001C */
    char	str[5];		/* 0x0021   "ZELDA" in created file */
    uint8_t	__pad_01[0x001];/* 0x0022 */
    uint16_t	death_count;	/* 0x0024 */
    uint8_t	name[8];	/* 0x002C Special char encoding */
    uint8_t     __pad_02[0x006];/* 0x0032 */
    uint32_t    rupee_count;    /* 0x0036 */
    uint8_t	__pad_03[0x002];/* 0x0038 */
    uint16_t	scene_count;	/* 0x003A May be uint32_t */
    uint8_t	__pad_04[0xE2A];/* 0x0E64 */
    struct
    {
    	float		x, y, z;	/* 0x0E70 */
    	uint16_t	y_rot;		/* 0x0E72 */
    	uint8_t		__pad_00[0x8];	/* 0x0E7A */
    	uint16_t	scene_no;	/* 0x0E7C */
    	uint32_t	map_no;		/* 0x0E80 */
    	uint32_t	isset;		/* 0x0E84 */
    }
    farore_warp;
    uint8_t	__pad_05[0x4CE];/* 0x1352 */
    uint16_t	chksum;		/* 0x1354 */
    uint8_t	__pad_06[0x0FC];/* 0x1540 */
}
z_save_file;

typedef struct
{
    uint8_t sound_opt;
    uint8_t ztarget_opt;
    char tag[5]; /* "ZELDA" (not null terminated) */
    z_save_file files[3];
}
z_save;

void
calc_chksum( z_save_file *f )
{
    int16_t *data = (int16_t*)(f);
    int sum = 0;
    int i;
    
    f->chksum = 0;

    for( i = 0; i < 0x9A9; i++ )
    {
        sum += data[i];
        sum &= 0xFFFF;
    }
    
    f->chksum = (uint16_t)sum;
}