Documentation
¶
Overview ¶
Package fat implements writing FAT16B file system images, which is useful when generating images for embedded devices such as the Raspberry Pi. With regards to reading, getting file offsets and lengths is implemented.
The resulting images use a cluster size of 4 sectors and a sector size of 512 bytes, i.e. their size is limited to about 127 MB.
Filenames are restricted to 8 characters + 3 characters for the file extension.
Example ¶
package main
import (
"io/ioutil"
"log"
"time"
"github.com/gokrazy/internal/fat"
)
func main() {
tmp, err := ioutil.TempFile("", "example")
if err != nil {
log.Fatal(err)
}
fw, err := fat.NewWriter(tmp)
if err != nil {
log.Fatal(err)
}
w, err := fw.File("etc/resolv.conf", time.Now())
if err != nil {
log.Fatal(err)
}
if _, err := w.Write([]byte("nameserver 8.8.8.8")); err != nil {
log.Fatal(err)
}
if err := fw.Flush(); err != nil {
log.Fatal(err)
}
if err := tmp.Close(); err != nil {
log.Fatal(err)
}
log.Printf("mount -o loop %s /mnt/loop", tmp.Name())
}
Output:
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Reader ¶
type Reader struct {
// contains filtered or unexported fields
}
Reader is a minimalistic FAT16B reader, which only aims to be compatible with file systems created by Writer.
func NewReader ¶
func NewReader(r io.ReadSeeker) (*Reader, error)
NewReader creates a new FAT16B Reader by reading file system metadata.
type Writer ¶
type Writer struct {
TotalSectors int // populated after Flush
// contains filtered or unexported fields
}
func NewWriter ¶
NewWriter returns a Writer which will write a FAT16B file system image to w once Flush is called.
Because the position of the data area in the resulting image depends on the size of the file allocation table and number of root directory entries, a temporary file is used to store data until Flush is called.
func (*Writer) File ¶
File creates a file with the specified path and modTime. The returned io.Writer stays valid until the next call to File, Flush or Mkdir.
Source Files