BarinkOS/kernel/filesystem/FAT/FAT.cpp

268 lines
7.7 KiB
C++

//
// Created by nigel on 21/02/23.
//
#include "FAT.h"
void FAT::Read()
{
}
void FAT::Open()
{
}
void FAT::Write()
{
}
void ParseDateInteger(unsigned int date){
printf("Date (hex) 0x%x\n", date);
unsigned int year = (date >> 9 )+ 1980;
unsigned int month = (date & 0xf0 ) >> 4;
unsigned int day = date & 0xf ;
printf("Date: (D,M,Y) %d, %d ,%d\n", day , month, year );
}
BiosParameterBlock* getBPB(MBR* mbr, bool DEBUG =false ){
BiosParameterBlock* bpb = (BiosParameterBlock*) malloc(sizeof(BiosParameterBlock));
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, mbr->TableEntries[0].LBA_partition_start, (uint16_t*) bpb);
if(DEBUG)
{
printf("OEM ID: %s\n", bpb->OEM_id);
printf("Bytes per sector: %d\n", bpb->BytesPerSector);
printf("Sectors per cluster: %d\n", bpb->SectorsPerCluster);
printf("Reserved sectors: %d\n", bpb->ReservedSectors);
printf("Number of FAT: %d\n", bpb->NumberOfFileAllocationTables);
printf("Number of Dir entries: %d\n", bpb->NumberOfDirectoryEntries);
printf("Total Sectors in volume: %d\n", bpb->TotalSectorsInLogicalVolume);
printf("Sectors per FAT: %d\n", bpb->NumberOfSectorsPerFAT);
}
return bpb;
}
uint16_t* ReadFAT (BiosParameterBlock& bpb , MBR& mbr, bool DEBUG = false ) {
uint32_t FATAddress = mbr.TableEntries[0].LBA_partition_start + bpb.ReservedSectors ;
uint16_t* FAT = (uint16_t*)malloc(sizeof (uint16_t) * 256);
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, FATAddress, FAT );
// Show data in terminal
if(DEBUG){
for( unsigned int i =0 ; i < 256 ; i++) {
printf("0x%x ", (unsigned short)FAT[i]);
}
kterm_put('\n');
}
return FAT;
}
void readFile(uint32_t DataRegion, DirectoryEntry* entry, uint16_t FATentry, BiosParameterBlock& bpb ){
printf("Show contents");
printf("Start cluster of the file: 0x%x\n", entry->StartingCluster);
printf("IS it only 1 cluster? %s\n", FATentry == 0xFFFF ? "Yes" : "No");
uint32_t sector = DataRegion + ((entry->StartingCluster - 0x02) * bpb.SectorsPerCluster);
uint16_t dataBlob[256];
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, sector, dataBlob);
for (unsigned short n: dataBlob) {
kterm_put(n & 0x00ff);
kterm_put(n >> 8);
}
kterm_put('\n');
}
void listFilesInRoot(MBR& mbr, BiosParameterBlock& bpb ){
auto FATAddress = mbr.TableEntries[0].LBA_partition_start + bpb.ReservedSectors;
uint32_t RootDirectoryRegion = FATAddress + ( bpb.NumberOfFileAllocationTables * bpb.NumberOfSectorsPerFAT );
uint32_t DataRegion = RootDirectoryRegion + ((bpb.NumberOfDirectoryEntries * 32) / bpb.BytesPerSector );
uint16_t* FAT = ReadFAT(bpb, mbr);
uint16_t data2 [256];
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, RootDirectoryRegion, data2 );
auto* RootDirectory = (DirectoryEntry*) data2;
// List files in root
for(int i= 0; i < sizeof (data2) / sizeof (DirectoryEntry); i++ ) {
auto *entry = (DirectoryEntry * )((uint32_t) RootDirectory + (i * sizeof(DirectoryEntry)));
if (entry->filename[0] == (uint8_t) 0x00)
continue; // There are no more entries in this directory or the entry is free
if (entry->attribute & ATTRIBUTES::ATT_HIDDEN)
continue;
if(entry->attribute & ATTRIBUTES::ATTR_SYSTEM)
continue;
if(entry->attribute & ATTRIBUTES::ATTR_VOLUME_ID)
continue;
// Print the filename;
for (char n: entry->filename) {
if (n == 0x20)
break;
kterm_put(n);
}
for (unsigned char n: entry->Extension) {
kterm_put(n);
}
kterm_put('\n');
printf("Attribute: %x \n", entry->attribute);
printf("FileSize: %d Bytes\n", entry->FilesizeInBytes);
if (entry->FilesizeInBytes != 0x0 && (entry->attribute != 0x10)) {
readFile(DataRegion,entry, FAT[i], bpb);
}
}
free(FAT);
}
FILE fsysFatDirectory (const char* DirectoryName){
FILE file;
unsigned char* buf;
PDIRECTORY directory;
char DosFileName[11];
ToDosFileName(DirectoryName, DosFileName, 11);
DosFileName[11] =0;
for (int sector=0; sector <14 ; sector++){
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, mountInfo.rootOffset + sector, (uint16_t*)buf);
directory = (PDIRECTORY) buf;
for (int i =0; i < 16; i++){
char name[11];
memcpy(name, directory->Filename, 11);
name[11]=0;
if(strncmp(DosFileName, name, 11) == 0){
strcpy(file.name, DirectoryName);
file.id = 0;
file.currentCluster = directory->FirstCluster;
file.eof = 0;
file.filelength = directory->FileSize;
if(directory->Attrib == 0x10){
file.flags = FS_DIRECTORY;
} else {
file.flags = FS_FILE;
}
return file;
}
directory++;
}
}
// Can't find file
file.flags = FS_INVALID;
return file;
}
void fsysFATRead(PFILE file, unsigned char* buffer, unsigned int length){
if(file){
unsigned int physSector = 32 + (file->currentCluster - 1);
const unsigned int SECTOR_SIZE = 512;
// read sector
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, physSector, (uint16_t*) buffer );
unsigned int FAT_Offset = file->currentCluster + (file->currentCluster /2);
unsigned int FAT_Sector = 1 + (FAT_Offset / SECTOR_SIZE);
unsigned int entryOffset =FAT_Offset % SECTOR_SIZE;
uint8_t FAT[SECTOR_SIZE*2];
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, FAT_Sector,(uint16_t*) FAT); // Read 1st FAT sector
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, FAT_Sector +1, (uint16_t*)FAT+SECTOR_SIZE);
// read entry for next cluster
uint16_t nextCluster = *(uint16_t*) &FAT[entryOffset];
// test if entry is odd or even
if(file->currentCluster & 0x0001){
nextCluster>>= 4; // grab the high 12 bits
}else{
nextCluster &= 0x0FFF; // grab the low 12 bits
}
// test for end of file
if(nextCluster >= 0xff8){
file->eof -1;
return;
}
// test for file corruption
if(nextCluster == 0){
file->eof =1;
return;
}
// set next cluster
file->currentCluster = nextCluster;
}
}
FILE fsysFatOpenSubDir(FILE kFile, const char* filename){
FILE file;
char DosFileName[11];
ToDosFileName(filename, DosFileName, 11);
DosFileName[11] = 0;
while(!kFile.eof){
//read directory
unsigned char buf[512];
fsysFATRead(&file, buf, 512);
PDIRECTORY pkDir = (PDIRECTORY) buf;
for (unsigned int i = 0; i < 16; i++){
// get current filename
char name[11];
memcpy(name, pkDir->Filename, 11);
name[11] = 0;
if(strncmp(name, DosFileName, 11) == 0){
strcpy(file.name, filename);
file.id = 0;
file.currentCluster = pkDir->FirstCluster;
file.filelength = pkDir->FileSize;
file.eof = 0;
// set file type;
if(pkDir->Attrib == 0x10){
file.flags = FS_DIRECTORY;
} else{
file.flags = FS_FILE;
}
return file;
}
// go to next entry
pkDir++;
}
}
// unable to find file
file.flags = FS_INVALID;
return file;
}