GLFS Spec (v0)

good little file system, version 0

(affectionately good luck file system, version 0)

GLFS Structure Overview

[sector 0] GLFS SUPERBLOCK
----------
- magic GLFS+version identifier

[sector 1+] DIRECTORY TABLE
-----------
     [entry 0] filename: string
               start sector: int
	       size: int (bytes)

     [entry 1] filename: string
               start sector: int
	       size: int (bytes)
     (...)
     
[end of table marker]
----------
[file data]
(...)

[0] Superblock Overview

• size: 512b
• contents:
  • bytes 0..7: GLFSv0\n (7 bytes+newline)
  • bytes 7..511: reserved

[sector 1+] Directory Table Overview

• each 40-byte directory entry contains:
  • 32 byte filename
  • 4 byte (uint32) start sector (offset from sector 0)
  • 4 byte (uint32) file size in bytes
• end of table is marked with b'__END__' (8 bytes)