Nigel/BarinkOS
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BarinkOS/kernel/vfs/VFS.cpp
Nigel dea8ab7d71 Improved build system 
Added new entries to .gitignore
Moved away from source directory as central spot for all source code
2023-02-20 00:29:06 +01:00

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#include "VFS.h"
#include "../filesystem/FAT/BiosParameterBlock.h"
#include "../drivers/ide/ide.h"
#include "../drivers/ata/ataDevice.h"
#include "../partitiontable/mbr/MasterBootRecord.h"
#include "../memory/KernelHeap.h"
#include "../../CoreLib/Memory.h"
#include "../filesystem/FAT/DirectoryEntry.h"
MOUNT_INFO mountInfo;
PFILESYSTEM _filesystems[DEVICE_MAX];
FILE volOpenFile(const char* fname)
{
if(fname){
unsigned char device = 'a';
char* filename = (char*) fname;
if(fname[1]== ':'){
device = fname[0];
filename += 2; // strip the volume component from the path
}
if(_filesystems[device - 'a']){
FILE file = _filesystems[device-'a']->Open(filename);
file.device = device;
return file;
}
}
FILE file;
file.flags = FS_INVALID;
return file;
}
extern void volReadFile(PFILE file, unsigned char* Buffer, unsigned int length)
{
}
extern void volCloseFile(PFILE file)
{
if( file->device < DEVICE_MAX){
// _filesystems[file->device]->Close(file);
}
}
extern void volRegisterFilesystem(PFILESYSTEM fsys , unsigned int deviceID){
if(deviceID < DEVICE_MAX)
if(fsys)
_filesystems[deviceID] = fsys;
}
extern void volUnregisterFilesystem(PFILESYSTEM){
}
extern void volUnregisterFileSystemByID(unsigned int deviceID){
}
enum BUS_PORT {
Primary = 0x1f0,
Secondary = 0x170
};
bool driveAvailable(){
int devNumber = 0;
for ( auto device : ide_devices){
if(!device.Reserved)
continue;
devNumber++;
}
// FIXME: If no drive is connected we continue trying to read from
// a not connected drive!
ATA_DEVICE::Identify((uint16_t) BUS_PORT::Primary, DEVICE_DRIVE::MASTER);
return true;
}
MBR* getPartitions(bool DEBUG = false){
const int C = 0;
const int H = 0;
const int HPC = 16;
const int SPT = 63;
int S =1;
uint32_t LBA = (C*HPC+H) * SPT + (S-1);
MBR* mbr =(MBR*) malloc(sizeof (MBR));
ATA_DEVICE::Read(BUS_PORT::Primary, DEVICE_DRIVE::MASTER, LBA, (uint16_t*)mbr);
if(DEBUG){
printf("BootSector: 0x%x\n", mbr->ValidBootsector );
for( int i = 0 ; i < 4 ; i ++){
PartitionTableEntry PT = mbr->TableEntries[i];
printf("Partition %d [ %d sectors, PartitionType: 0x%x, 0x%x, \nLBA Start: 0x%x ]\n" ,
i, PT.Number_sectors_inPartition, PT.PartitionType, mbr->uniqueID, PT.LBA_partition_start );
}
}
return mbr;
}
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 & 0x01) == 0x01 || (entry->attribute & 0x20) == 0x20)
continue; // Skip listing if hidden or Achieve flag is set
// 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 == 0x08)) {
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;
}
*/
void FileSystem::initialize()
{
MBR* mbr = getPartitions();
BiosParameterBlock* bootsector = getBPB(mbr);
listFilesInRoot(*mbr, *bootsector);
free(mbr);
free(bootsector);
/*
mountInfo.numSectors = bootsector->NumberOfSectorsPerFAT;
mountInfo.fatOffset = 1;
mountInfo.fatSize = bootsector->NumberOfSectorsPerFAT;
mountInfo.fatEntrySize = 8;
mountInfo.numRootEntries = bootsector->NumberOfDirectoryEntries;
mountInfo.rootOffset = (bootsector->NumberOfFileAllocationTables * bootsector->NumberOfSectorsPerFAT) + 1;
mountInfo.rootSize = (bootsector->NumberOfDirectoryEntries * 32) / bootsector->BytesPerSector;
*/
}
char* FindNextEntryName (char* path )
{
int length = strlen(path);
char* name = path;
int i = 0;
if( name[0] == '/')
i++;
while ( name[i] != '/' && i <= length)
i++;
char* s = (char*) malloc(i + 1 * sizeof(char));
for ( int a = 0; a < i; a++)
s[a] = path[a];
s[i + 1] = '\0';
return s;
}
void FileSystem::ResolvePath(Path &path)
{
// See reference material (1) https://man7.org/linux/man-pages/man7/path_resolution.7.html
char* string_path = path.str();
void* cpy = string_path;
bool isAbsolutePath = string_path[0] == '/';
if(isAbsolutePath)
{
// strip the first slash
string_path++;
}
char* entry_name = FindNextEntryName(string_path);
printf("Look for entry with name: %s\n", entry_name);
int skip = strlen(entry_name);
free(entry_name);
entry_name = FindNextEntryName(string_path + skip);
printf("Look for entry with name: %s\n", entry_name);
skip = strlen(entry_name);
free(entry_name);
free(cpy);
}
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