gc

README

gc

A library for reading and writing Nintendo GameCube memory card images.

Documentation

Index

• Constants
• func CardSize(cardSize uint16) func(*Writer) error
• func DetectMemoryCard(r io.ReaderAt, size int64) (bool, error)
• func Encoding(encoding uint16) func(*Writer) error
• func FlashID(flashID [12]byte) func(*Writer) error
• func FormatTime(formatTime uint64) func(*Writer) error
• type File
  • func (f *File) Open() (fs.File, error)
• type FileHeader
  • func (h *FileHeader) FileInfo() fs.FileInfo
  • func (h *FileHeader) Mode() fs.FileMode
• type ReadCloser
  • func OpenReader(name string) (*ReadCloser, error)
  • func (rc *ReadCloser) Close() error
• type Reader
  • func NewReader(r io.Reader) (*Reader, error)
  • func (r *Reader) Open(name string) (fs.File, error)
• type Writer
  • func NewWriter(w io.Writer, options ...func(*Writer) error) (*Writer, error)
  • func (w *Writer) Close() error
  • func (w *Writer) Create() (io.WriteCloser, error)

Examples

• Writer

Constants

const (
	MemoryCard59 uint16 = 4 << iota
	MemoryCard123
	MemoryCard251
	MemoryCard507
	MemoryCard1019
	MemoryCard2043
)

Supported memory card sizes.

const (
	EncodingANSI uint16 = iota
	EncodingSJIS
)

Supported memory card encodings.

Functions

func CardSize

func CardSize(cardSize uint16) func(*Writer) error

CardSize sets the memory card capacity.

func DetectMemoryCard

func DetectMemoryCard(r io.ReaderAt, size int64) (bool, error)

DetectMemoryCard works out if the io.ReaderAt r pointing to the data of size bytes looks sufficiently like a GameCube memory card image.

func Encoding

func Encoding(encoding uint16) func(*Writer) error

Encoding sets the memory card encoding.

func FlashID

func FlashID(flashID [12]byte) func(*Writer) error

FlashID sets the 12 byte Flash ID. If the target is an official memory card then this must be set correctly.

func FormatTime

func FormatTime(formatTime uint64) func(*Writer) error

FormatTime overrides the formatting time, which is expressed in seconds since 00:00:00, 1st January 2000. Setting it to 0 stops the serial number from being computed.

Types

type File

type File struct {
	FileHeader
	GameCode  string
	MakerCode string
	// contains filtered or unexported fields
}

A File is a single file within a memory card.

func (*File) Open

func (f *File) Open() (fs.File, error)

Open returns an fs.File that provides access to the File's contents. The file is prefixed with a 64 byte header (the directory entry) followed by one or more 8 KiB blocks. Multiple files may be read concurrently.

type FileHeader

type FileHeader struct {
	Name     string
	Modified time.Time
	Size     int64
}

FileHeader describes a file within a memory card.

func (*FileHeader) FileInfo

func (h *FileHeader) FileInfo() fs.FileInfo

FileInfo returns an fs.FileInfo for the FileHeader.

func (*FileHeader) Mode

func (h *FileHeader) Mode() fs.FileMode

Mode returns the permission and mode bits for the FileHeader.

type ReadCloser

type ReadCloser struct {
	Reader
	// contains filtered or unexported fields
}

A ReadCloser is a Reader that must be closed when no longer needed.

func OpenReader

func OpenReader(name string) (*ReadCloser, error)

OpenReader will open the memory card image specified by name and return a ReadCloser.

func (*ReadCloser) Close

func (rc *ReadCloser) Close() error

Close closes the memory card image, rendering it unusable for I/O.

type Reader

type Reader struct {
	File []*File

	FlashID  [12]byte
	CardSize uint16
	Encoding uint16
	// contains filtered or unexported fields
}

A Reader serves content from a memory card image.

func NewReader

func NewReader(r io.Reader) (*Reader, error)

NewReader returns a new Reader reading from r.

func (*Reader) Open

func (r *Reader) Open(name string) (fs.File, error)

Open opens the named file in the memory card image, using the semantics of fs.FS.Open: paths are always slash separated, with no leading / or ../ elements.

type Writer

type Writer struct {
	// contains filtered or unexported fields
}

A Writer is used for creating a new memory card image with files written to it.

Example

package main

import (
	"bytes"
	"fmt"

	"github.com/bodgit/gc"
)

func main() {
	buf := new(bytes.Buffer)

	w, err := gc.NewWriter(buf)
	if err != nil {
		panic(err)
	}

	if err := w.Close(); err != nil {
		panic(err)
	}

	fmt.Println(buf.Len())
}

Output:

524288

func NewWriter

func NewWriter(w io.Writer, options ...func(*Writer) error) (*Writer, error)

NewWriter returns a Writer targeting a new blank memory card which defaults to 59 block capacity, ANSI encoding and an all-zeroes Flash ID.

func (*Writer) Close

func (w *Writer) Close() error

Close writes out the memory card to the underlying io.Writer. Any in-flight open memory card files are closed first.

func (*Writer) Create

func (w *Writer) Create() (io.WriteCloser, error)

Create returns an io.WriteCloser for writing a new file on the memory card. The file should consist of a 64 byte header followed by one or more 8 KiB blocks as indicated in the header.