fs.h File Reference

File system, adds file system interruption in int0x21() More...

#include <types.h>
#include <errno.h>
#include <io.h>
#include <string.h>
#include "interrupts.h"

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Macros
#define	FILENAME_MAX   16
	Maximal size of file name.
#define	SECTORS_PER_TRACK   37
	Number of sectors per track. More...
#define	TRACKS_MAX   3
	Maximal number of tracks in OS. More...

Functions
void	__strncpy (char *destination, const char *source, size_t num)
	Copy from ss:source to cs:destination.
int	sys_setup ()
	load file system More...
int	sys_open (const int filename)
	Open file. More...
int	sys_create (const int filename, size_t size)
	Create file. More...
int	sys_remove (const int filename)
	Remove file. More...
int	sys_read (const Byte id, int ptr, size_t size)
	Read from file. More...
int	sys_write (Byte id, int ptr, size_t size)
	Write to file. More...
__int void	int0x21 (interruptFrame *frame)
	interruption for file system More...

Variables
struct {
char   name [FILENAME_MAX]
Byte   track
Byte   beginSector
Byte   size
} *	files
bool	map [TRACKS_MAX][SECTORS_PER_TRACK]
	Map of used sectors in tracks.
size_t	numberOfFiles = 0

Detailed Description

File system, adds file system interruption in int0x21()

Adds file management

Attention

Only for kernel use, users should use file.h

Todo:

better handle disk errors see info.c, check if CF is set after reading/writing

Definition in file fs.h.

Macro Definition Documentation

SECTORS_PER_TRACK

#define SECTORS_PER_TRACK   37

Number of sectors per track.

Depends on floppy mode, 18 for 1.44 or 36 for 2.88, I use 2.88

Todo:

to avoid breaking file into tracks see sys_create()

Definition at line 30 of file fs.h.

TRACKS_MAX

#define TRACKS_MAX   3

Maximal number of tracks in OS.

Todo:

do it dynamically

Definition at line 36 of file fs.h.

Function Documentation

int0x21()

__int void int0x21

(

interruptFrame *

frame

)

interruption for file system

sets all sys_* functions as interruption see interrupts-asm.c and interrupts.h

AH	Description	BX	CX	DX	Returned AX
0	sys_setup()				Number of loaded files
1	sys_open()	file name			(file ID)<<8 | (file size (in sectors))
2	sys_read()	file id	memory beginning	size in B	Actually readed Bytes
3	sys_write()	file id	memory beginning	size in B	Actually saved Bytes (completed to 512B)
4	sys_create()	file name	new file size in Sec		file's ID
4	sys_remove()	file name			0 if success

Parameters

registers

AX, BX, CX, DX, SI, DI

Returns

register AX

Todo:

change order of ah

Definition at line 310 of file fs.h.

sys_create()

int sys_create	(	const int	filename,
		size_t	size
	)

Create file.

Parameters

filename
size	in sectors(512B)

Returns

int new file's id or -error

Todo:

file must be all in one track, change it

add it to sys_open when file wasn't found

Definition at line 120 of file fs.h.

sys_open()

int sys_open

(

const int

filename

)

Open file.

Parameters

filename

Returns

int {size in Sectors(512B),id} or -error

Definition at line 101 of file fs.h.

sys_read()

int sys_read	(	const Byte	id,
		int	ptr,
		size_t	size
	)

Read from file.

Parameters

id	file's id
ptr	pointer to target memory
size	to read in bytes

Returns

int actually readed Bytes or -error

Definition at line 203 of file fs.h.

sys_remove()

int sys_remove

(

const int

filename

)

Remove file.

Parameters

filename

Returns

int 0 if success or -error

Definition at line 171 of file fs.h.

sys_setup()

int sys_setup

(

)

load file system

Returns

int number of loaded files

Definition at line 81 of file fs.h.

sys_write()

int sys_write	(	Byte	id,
		int	ptr,
		size_t	size
	)

Write to file.

Parameters

id	file's id
ptr	pointer to source memory
size	to write in Bytes, file will be rounded to whole sectors

Returns

int actually written Bytes or -error

Todo:

add modes, when append when override

Definition at line 249 of file fs.h.