Filesystem

Filesystem

Function

The function of the filesystem is to provide a structure for each program, library or other file that is stored or loaded into RAM. It specifies things like the program/library/file name.

Specifications

Every page is 512 words in size. There are a total of ? pages. (? = unknown since the size of the kernel is unknown at this moment).

FAT table

Contains one-word references to next cluster of a file or 0xFFFF if EOF. It's located on the floppy in a sector specified in floppy FAT header.

File header

All files and directories (except root) are preceded by a header that contains metadata denoting useful characteristics of said file. The header is 0x10 words long and breaks down according to this scheme: Words

•   0x0-0x5    filename converted from 12 char word
  

•   0x6        file type, according to the RFC
  

•   0x7-0x8    DateTime of creation in multiplies of 1s since 1.1.1970
  

•   0x9-0xA    DateTime of modification
  

•   0xB-0xC    DateTime of view
  

•   0xD        Starting cluster of parent directory
  

•   0xE-0xF    File size in words
  

Further reference:

https://gist.github.com/2782945

(I do not know if we use the above system exactly as mentioned there, if we do, please remove this comment and add that specification to this page, thanks -M52).