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fat12.c File Reference

FAT-12 fyle system. More...

#include <const.h>
#include <string.h>
#include <arch/mem.h>
#include <kernel/console.h>
#include <kernel/floppy.h>
#include <kernel/keyboard.h>
#include <kernel/kmalloc.h>
#include <kernel/fat.h>

Go to the source code of this file.

Functions
bool	next_sector (word *next, word actual)
int	how_many_cluster (word start)
void	int_to_date (date_t *d, word date)
void	int_to_time (fat_time_t *time, word t)
void	read_attrib (attrib_t *FileAttr, byte attrib)
char *	show_attrib (attrib_t *FileAttr, char *stringa)
char *	file_name (FileEntry_t *temp, char *stringa)
bool	show_file_entry (FileEntry_t *TempFile)
void	name_ext (char *filename, char *name, char *ext)
bool	compare_name_ext (unsigned char *name1, unsigned char *name2, char *ext1, char *ext2)
void	read_file (sector_t *Buf, int start, int c)
bool	load_file (char *stringa, byte *buffer)
int	get_file_size (char *file_name)
void	ls ()
bool	cat (char *stringa)
void	add_dir_path (char *new_path)
void	up_dir_path (void)
char *	pwd ()
bool	cd (char *new_path)
bool	fat12_write ()
word	find_sector (int n, word actual)
void	write_sector_dir (SectorDir_t *sector, int num)
void	delete_file (word cluster)
bool	rm (char *filename)
bool	init_FAT ()
bool	check_FAT (void)
bool	Read_FAT ()
Variables
bootsect_t	bootsector
FAT12_t	fat
logical_FAT12_t	lfat
word	directory = 0
char	path [256]

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Detailed Description

FAT-12 fyle system.

Author:

Matteo Chesi <dalamar@inwind.it> Rudy Manganelli <feller@libero.it> Andrea Righi <drizzt@inwind.it>

Date:

Last update: 2003-11-09

Note:

Copyright (©) 2003 Matteo Chesi <dalamar@inwind.it> Rudy Manganelli <feller@libero.it> Andrea Righi <drizzt@inwind.it>

Definition in file fat12.c.

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Function Documentation

void add_dir_path (  char *    new_path )

Definition at line 438 of file fat12.c. { strcat(path, new_path); strcat(path, "/"); }

bool cat (  char *    stringa )

Definition at line 388 of file fat12.c. { unsigned char Nome[9], Ext[4]; SectorDir_t *Buf, *Buf2; word sector; int counter; int h, i; bool a=FALSE; name_ext(stringa, Nome, Ext); counter = how_many_cluster(directory); Buf = kmalloc(FAT_SECTOR_SIZE*counter); memset(Buf, 0, FAT_SECTOR_SIZE*counter); read_file((sector_t *)Buf, directory, counter); for(h=0; h<counter; h++) { for(i=0; i<FAT_SECTOR_SIZE/sizeof(FileEntry_t); i++) { a = compare_name_ext(Buf[h].Entry[i].Name, Nome, Buf[h].Entry[i].Extension, Ext); if (a) { // The file is empty // if ( !(Buf[h].Entry[i].StartCluster) ) goto founded; // Print the file to the standard output // sector = Buf[h].Entry[i].StartCluster; Buf2 = kmalloc(sizeof(sector_t)); memset(Buf2, 0, sizeof(sector_t)); for (;;) { read_file((sector_t *)Buf2, sector, 1); for (i=0; i<FAT_SECTOR_SIZE; i++) { kputchar( ((byte *)Buf2)[i] ); } if (!(next_sector(&sector, sector))) break; } kfree(Buf2); goto founded; } } } founded: kfree(Buf); if (!a) return(FALSE); return(TRUE); }

bool cd (  char *    new_path )

Definition at line 458 of file fat12.c. { int counter=0; int l, h, i; bool change=FALSE; word a=0; attrib_t FileAttr; char dir_name[8]; SectorDir_t *Buf; // Goto the root // if (new_path[0]=='/') if (new_path[1]=='\0') { path[0]='\0'; directory=0; return(TRUE); } counter = how_many_cluster(directory); Buf = kmalloc(FAT_SECTOR_SIZE*counter); memset(Buf, 0, FAT_SECTOR_SIZE*counter); read_file((sector_t *)Buf, directory, counter); for(h=0; h<counter; h++) { for(i=0; i<FAT_SECTOR_SIZE/sizeof(FileEntry_t); i++) { read_attrib(&FileAttr, Buf[h].Entry[i].Attribute); if (FileAttr.Directory) { if ((Buf[h].Entry[i].Name[0]!=0)&&(Buf[h].Entry[i].Name[0]!=0xE5)) { if (Buf[h].Entry[i].Name[0]==5) Buf[h].Entry[i].Name[0]=0xE5; l=0; do { dir_name[l]=Buf[h].Entry[i].Name[l]; } while(dir_name[l++]!=' '); dir_name[--l]='\0'; if (strcmp(new_path, dir_name)==0) { a = Buf[h].Entry[i].StartCluster; change=TRUE; goto founded; } if (Buf[h].Entry[i].Name[0]==0xE5) Buf[h].Entry[i].Name[0]=0x05; } } } } founded: kfree(Buf); if (change) { directory = a; if (!a) path[0]='\0'; else { if(new_path[0] != '.') add_dir_path(new_path); else { if (new_path[1] == '.') up_dir_path(); } } return TRUE; } else return FALSE; }

bool check_FAT (  void    )

Definition at line 661 of file fat12.c. { if ( (bootsector.BytesPerSector!=FAT_SECTOR_SIZE) || (bootsector.SectorsPerCluster!=1) || (bootsector.Fats!=2) || (bootsector.RootDirectoryEntries!=224) || (bootsector.LogicalSectors!=2880) || (bootsector.MediumDescriptorByte!=0xF0) ) { kprintf("\n\rNot a valid FAT12 filesystem on the disk.\n\r"); return FALSE; } return TRUE; }

bool compare_name_ext (  unsigned char *    name1, unsigned char *    name2, char *    ext1, char *    ext2 )

Definition at line 217 of file fat12.c. { bool different = TRUE; if ( (*name1 != 0) && (*name1 != 0xE5) ) { if (*name1 == 0x05) *name1=0xE5; if ( (strncmp(name1, name2, 8) == 0) && (strncmp(ext1, ext2, 3) == 0) ) different = FALSE; if (*name1 == 0xE5) *name1=0x05; } return(!different); }

void delete_file (  word    cluster )

Definition at line 593 of file fat12.c. { // Delete the file from the FAT structure // word next; while ( next_sector(&next, cluster) ) { lfat.data[cluster] = 0; cluster = next; } lfat.data[cluster] = 0; }

bool fat12_write (    )

Definition at line 534 of file fat12.c. { // Write the logical FAT to the disk // int i, j; // Converts the FAT from the logical structure into the // // physical structure // for(i=0, j=0; j<3072; j+=2) { fat.data[i++] = (byte)lfat.data[j]; fat.data[i++] = (byte)((lfat.data[j]>>8)&(0x0F))|((lfat.data[j+1]<<4)&(0xF0)); fat.data[i++] = (byte)(lfat.data[j+1]>>4); } // Copy the FAT to the disk // for(j=0; j<bootsector.Fats; j++) { for(i=0; i<3; i++) if ( fdc_write(1, (byte *)&fat, bootsector.SectorsPerFat) ) break; if (i == 3) return(FALSE); } // Write successful! // return(TRUE); }

char* file_name (  FileEntry_t *    temp, char *    stringa )

Definition at line 112 of file fat12.c. { int k, a; a=0; for(k=0; k<8; k++) { if ((temp->Name[k]!=0)&&(temp->Name[k]!=' ')) { stringa[k]=temp->Name[k]; a=k; } } for(k=0;k<3;k++) { if (temp->Extension[k]!=' ') { if (k==0) stringa[++a]='.'; stringa[++a]=temp->Extension[k]; } } for(a++;a<12;a++) stringa[a]=' '; stringa[12]='\0'; return stringa; }

word find_sector (  int    n, word    actual )

Definition at line 562 of file fat12.c. { // Find the sector n from actual // word c, temp; temp = actual; for(c=0; c<n; c++) next_sector(&temp, temp); return(temp); }

int get_file_size (  char *    file_name )

Definition at line 311 of file fat12.c. { // Get the size of a file // unsigned char name[9], ext[4]; SectorDir_t *Buf; int counter, count=0, h, i; bool found=FALSE; // Get the file name and extension // name_ext(file_name, name, ext); // Get the list of file into the current directory // counter = how_many_cluster(directory); Buf = kmalloc(FAT_SECTOR_SIZE*counter); memset(Buf, 0, FAT_SECTOR_SIZE*counter); // Read the directory // read_file((sector_t *)Buf, directory, counter); // Find the file // for(h=0; h<counter; h++) { for(i=0; i<FAT_SECTOR_SIZE/sizeof(FileEntry_t); i++) { found = compare_name_ext(Buf[h].Entry[i].Name, name, Buf[h].Entry[i].Extension, ext); if (found) { // The file is empty // if ( !(Buf[h].Entry[i].StartCluster) ) goto founded; // Get the size in clusters // count = how_many_cluster(Buf[h].Entry[i].StartCluster); goto founded; } } } founded: kfree(Buf); if (!found) return(-1); return(count*FAT_SECTOR_SIZE); };

int how_many_cluster (  word    start )

Definition at line 43 of file fat12.c. { word c=1, cl; // The root directory (start=0) has a fixed size // if (!start) return( (bootsector.RootDirectoryEntries*sizeof(FileEntry_t))/bootsector.BytesPerSector ); // Calculate the size of the directory (it's not the root!) // cl=start; while (next_sector(&cl, cl)) c++; return(c); }

bool init_FAT (    )

Definition at line 647 of file fat12.c. { // Initialize the file system // int i; for(i=0; i<3; i++) if (fdc_read(FAT_BOOT_SECTOR, (byte *)&bootsector, 1)) break; if (i != 3) return(TRUE); else return(FALSE); }

void int_to_date (  date_t *    d, word    date )

Definition at line 58 of file fat12.c. { d->year=date/512; d->month=(date-(d->year*512))/32; d->day=date-(d->year*512)-(d->month*32); }

void int_to_time (  fat_time_t *    time, word    t )

Definition at line 65 of file fat12.c. { time->hour=t/2048; time->minute=(t-(time->hour*2048))/32; time->second=(t-(time->hour*2048)-(time->minute*32))*2; }

bool load_file (  char *    stringa, byte *    buffer )

Definition at line 267 of file fat12.c. { unsigned char Nome[9], Ext[4]; SectorDir_t *Buf; int counter, count; int h, i; bool found=FALSE; // Get the file name and extension // name_ext(stringa, Nome, Ext); // Get the list of file into the current directory // counter = how_many_cluster(directory); Buf = kmalloc(FAT_SECTOR_SIZE*counter); memset(Buf, 0, FAT_SECTOR_SIZE*counter); // Read the directory // read_file((sector_t *)Buf, directory, counter); for(h=0; h<counter; h++) { for(i=0; i<FAT_SECTOR_SIZE/sizeof(FileEntry_t); i++) { found = compare_name_ext(Buf[h].Entry[i].Name, Nome, Buf[h].Entry[i].Extension, Ext); if (found) { // The file is empty // if ( !(Buf[h].Entry[i].StartCluster) ) goto founded; // Copy the file into the buffer // count = how_many_cluster(Buf[h].Entry[i].StartCluster); read_file((sector_t *)buffer, Buf[h].Entry[i].StartCluster, count); goto founded; } } } founded: kfree(Buf); if (!found) return(FALSE); return(TRUE); }

void ls (    )

Definition at line 352 of file fat12.c. { int counter=0; int h, i, scroll; SectorDir_t *Buf; counter = how_many_cluster(directory); Buf = kmalloc(FAT_SECTOR_SIZE*counter); memset(Buf, 0, FAT_SECTOR_SIZE*counter); read_file((sector_t *)Buf, directory, counter); kprintf("\nList of files into the directory:\n\r\n\r"); for(h=0, scroll=0; h<counter; h++) { for(i=0; i<(bootsector.BytesPerSector/sizeof(FileEntry_t)); i++) { if (scroll==20) { kprintf("\n\rPress a key to continue...\n\r"); scroll=0; if (kgetchar() == CTRL_C) { kprintf("\n\r"); kfree(Buf); return; } } if ( show_file_entry(&(Buf[h].Entry[i])) ) scroll++; } } kfree(Buf); kprintf("\n\r"); }

void name_ext (  char *    filename, char *    name, char *    ext )

Definition at line 177 of file fat12.c. { int i; unsigned char *find; // Set the string to uppercase // strtoupper(filename); // Get the file name // for(i=0; i<8; i++) { if ( (filename[i]=='.') || (filename[i]=='\0') ) break; name[i] = filename[i]; } for(; i<8; i++) name[i] = ' '; name[8] = '\0'; // Get the file extension // find = strstr(filename, "."); if (find++) { for(i=0; i<3; i++) { if (find[i]=='\0') break; ext[i] = find[i]; } for(; i<3; i++) ext[i] = ' '; } else { for(i=0; i<3; i++) ext[i] = ' '; } ext[3] = '\0'; }

bool next_sector (  word *    next, word    actual )

Definition at line 34 of file fat12.c. { *next = lfat.data[actual]; if ( (*next == 0) || (*next >= 0x0FF0) ) return(FALSE); else return(TRUE); }

char* pwd (    )

Definition at line 452 of file fat12.c. { // Return the current path // return(path); }

void read_attrib (  attrib_t *    FileAttr, byte    attrib )

Definition at line 72 of file fat12.c. { FileAttr->RW= (attrib & (byte)0x1) && 0x1; FileAttr->Hidden= (attrib & (byte)0x2) && 0x2; FileAttr->System= (attrib & (byte)0x4) && 0x4; FileAttr->Label= (attrib & (byte)0x8) && 0x8; FileAttr->Directory=(attrib & (byte)0x10)&& 0x10; FileAttr->Archived= (attrib & (byte)0x20)&& 0x20; FileAttr->Reserved= attrib>>6; }

bool Read_FAT (    )

Definition at line 673 of file fat12.c. { // Read the FAT from the floppy (mount) // int i, j; if (!( init_FAT() )) { kprintf("\n\rFloppy I/O error. Unable to read the block!!!\n\r"); return(FALSE); } // FAT initializazion OK! // for (i=0; i<3; i++) if (fdc_read(1, (byte *)&fat, bootsector.SectorsPerFat)) break; if (i == 3) { kprintf("\n\rFloppy I/O error. Unable to read the block!!!\n\r"); return(FALSE); } // Converts the FAT into the logical structures (array of word) // for(i=0, j=0; i<4608; i+=3) { lfat.data[j++] = (fat.data[i] + (fat.data[i+1] << 8)) & 0x0FFF; lfat.data[j++] = (fat.data[i+1] + (fat.data[i+2] << 8)) >> 4; } // Check if the FAT is correct // if (!( check_FAT() )) { kprintf("\n\rNot a valid FAT12 filesystem!!!\n\r"); return(FALSE); } // Initialize the path // path[0]='\0'; #ifdef FAT_DEBUG kprintf("\n\rInitializing FileSystem...\n\r"); kprintf("\n\r"); kprintf("Jump:\t\t\t%02x %02x %02x\n\r", bootsector.Jump[0], bootsector.Jump[1], bootsector.Jump[2]); kprintf("OS Name:\t\t\t%s\n\r", bootsector.Name); kprintf("BytesPerSector:\t\t\t%u\n\r", bootsector.BytesPerSector); kprintf("SectorsPerCluster:\t\t\t%u\n\r", bootsector.SectorsPerCluster); kprintf("ReservedSectors:\t\t\t%u\n\r", bootsector.ReservedSectors); kprintf("Fats:\t\t\t%u\n\r", bootsector.Fats); kprintf("RootDirectoryEntries:\t\t\t%u\n\r", bootsector.RootDirectoryEntries); kprintf("LogicalSectors:\t\t\t%u\n\r", bootsector.LogicalSectors); kprintf("MediumDescriptorByte:\t\t\t%X\n\r", bootsector.MediumDescriptorByte); kprintf("SectorsPerFat:\t\t\t%u\n\r", bootsector.SectorsPerFat); kprintf("SectorsPerTrack:\t\t\t%u\n\r", bootsector.SectorsPerTrack); kprintf("Heads:\t\t\t%u\n\r", bootsector.Heads); kprintf("HiddenSectors:\t\t\t%u\n\r", bootsector.HiddenSectors); kprintf("\n\r"); #endif return(TRUE); }

void read_file (  sector_t *    Buf, int    start, int    c )

Definition at line 233 of file fat12.c. { int i, j; word a; word dir_start = bootsector.Fats*bootsector.SectorsPerFat+1; word data_start = dir_start + bootsector.RootDirectoryEntries*32/bootsector.BytesPerSector-2; if(!start) { for(j=0; j<3; j++) if (fdc_read(dir_start, (byte *)Buf, c)) break; } else { // Read the start sector // a=start; for(j=0; j<3; j++) if (fdc_read(data_start+a, (byte *)Buf, 1)) break; // Read the other sectors // for(i=1; i<c; i++) { if (next_sector(&a, a)) { for(j=0; j<3; j++) if (fdc_read(data_start+a, (byte *)(Buf+i), 1)) break; } else // End of file // break; } } }

bool rm (  char *    filename )

Definition at line 606 of file fat12.c. { // Remove a file from the disk // unsigned char name[9], ext[4]; SectorDir_t *Buf; int counter, h, i; bool a=FALSE; if ( (strcmp(filename, ".")==0) || (strcmp(filename, "..")==0) ) return(FALSE); name_ext(filename, name, ext); counter = how_many_cluster(directory); Buf = kmalloc(FAT_SECTOR_SIZE*counter); memset(Buf, 0, FAT_SECTOR_SIZE*counter); read_file((sector_t *)Buf, directory, counter); for(h=0; h<counter; h++) { for(i=0; i<FAT_SECTOR_SIZE/sizeof(FileEntry_t); i++) { a = compare_name_ext(Buf[h].Entry[i].Name, name, Buf[h].Entry[i].Extension, ext); if (a) { // Delete the file // Buf[h].Entry[i].Name[0] = 0xE5; write_sector_dir(&Buf[h], h); delete_file(Buf[h].Entry[i].StartCluster); fat12_write(); goto founded; } } } founded: kfree(Buf); if (!a) return(FALSE); return(TRUE); }

char* show_attrib (  attrib_t *    FileAttr, char *    stringa )

Definition at line 83 of file fat12.c. { if (FileAttr->Label) { stringa="LABEL "; return stringa; } if (FileAttr->Directory) { stringa="DIR "; return stringa; } stringa[0]='r'; if (FileAttr->RW) stringa[1]='-'; //ReadOnly else stringa[1]='+';//Read and Write stringa[2]='h'; if (FileAttr->Hidden) stringa[3]='+'; //Hidden else stringa[3]='-';//Visible stringa[4]='s'; if (FileAttr->System) stringa[5]='+'; //System else stringa[5]='-';//NonSystem stringa[6]='a'; if (FileAttr->Archived) stringa[7]='+'; //Archived else stringa[7]='-';//NotArchived stringa[8]='\0'; return stringa; }

bool show_file_entry (  FileEntry_t *    TempFile )

Definition at line 139 of file fat12.c. { date_t FileDate; fat_time_t FileTime; attrib_t FileAttr; char Attributi[8]; char Nome[13]; read_attrib(&FileAttr, TempFile->Attribute); if (!FileAttr.Label) { if ( (TempFile->Name[0]) && (TempFile->Name[0]!=0xE5) ) { if (TempFile->Name[0]==0x05) TempFile->Name[0]=0xE5; int_to_date(&FileDate, TempFile->Date); int_to_time(&FileTime, TempFile->Time); kprintf("%s", file_name(TempFile, Nome)); gotoxy(15, -1); kprintf("%s", show_attrib(&FileAttr, Attributi)); gotoxy(25, -1); kprintf("%d/%d/%u", FileDate.day, FileDate.month, (FileDate.year+1980)); gotoxy(36, -1); kprintf("%d:%d:%d", FileTime.hour, FileTime.minute, FileTime.second); gotoxy(46, -1); kprintf("S:%#x", TempFile->StartCluster); gotoxy(60, -1); kprintf("D:%u", TempFile->FileLength); kprintf("\n\r"); if (TempFile->Name[0]==0xE5) TempFile->Name[0]=0x05; return TRUE; } } return FALSE; }

void up_dir_path (  void    )

Definition at line 444 of file fat12.c. { int i, k; for(i=0; path[i]!='\0'; i++); for(k=(i-2); path[k]!='/'; k--); path[++k] = '\0'; }

void write_sector_dir (  SectorDir_t *    sector, int    num )

Definition at line 572 of file fat12.c. { int i, j; word dir_start = bootsector.Fats*bootsector.SectorsPerFat+1; word data_start = dir_start + bootsector.RootDirectoryEntries*32/bootsector.BytesPerSector-2; if( !directory ) { for(j=0; j<3; j++) if ( fdc_write(dir_start+num, (byte *)sector, 1) ) break; } else { i = find_sector(num, directory); for(j=0; j<3; j++) if ( fdc_write(data_start+i, (byte *)sector, 1) ) break; } }

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Variable Documentation

bootsect_t bootsector

Definition at line 27 of file fat12.c.

word directory = 0

Definition at line 30 of file fat12.c.

FAT12_t fat

Definition at line 28 of file fat12.c.

logical_FAT12_t lfat

Definition at line 29 of file fat12.c.

char path[256]

Definition at line 31 of file fat12.c.

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