BarinkOS/kernel/storage/vfs/vfs.cpp
Nigel 50bf952a49 Basic idea's are created for the storage solution
- Added boot device info parsing to the kernel
- Added a pointer in the kernel to our pre-kernel BootInfo structure
- Created a layout for the FAT driver
- Created a layout for the virtual filesystem
- Separated IDE driver from the basic atapio driver.
	This will ensure we are not using one or the other
- The create_harddrive shell script will now actually build a harddrive image of
	the kernel
- The virtual filesystem initializes and creates a filesystem structure
	for every FAT16 partition in the master boot record
2023-02-21 21:43:14 +01:00

131 lines
3.8 KiB
C++

#include "vfs.h"
#include <stdint-gcc.h>
#include "../../memory/KernelHeap.h"
#include "../ata pio/ATAPIO.h"
#include "../partitiontables/mbr/MasterBootRecord.h"
#include "../filesystems/FAT/FAT.h"
#include "StorageTypes.h"
#include <CoreLib/Memory.h>
PFS VirtualFileSystem::_filesystems[VirtualFileSystem::DEVICE_MAX];
PTR_PARTITION VirtualFileSystem::_partitions [VirtualFileSystem::PARTITION_MAX];
unsigned int VirtualFileSystem::num_partitions = 0;
void VirtualFileSystem::initialize()
{
// Mount the boot disk
// NOTE: we assume for now that it is the only disk in the system
// This information could possibly be had from the bootloader (GRUB)
// We als assume it is the primary device on the Master port.
ATAPIO::Soft_Reset(ATAPIO_PORT::Primary, DEVICE_DRIVE::MASTER);
bool isAvailable = ATAPIO::Identify(ATAPIO_PORT::Primary, DEVICE_DRIVE::MASTER);
if(!isAvailable){
// PANIC!!!
printf("Failed to mount root filesystem!\n");
return;
}
auto masterbootrecord = GetPartitions(false);
for (auto partition : masterbootrecord->TableEntries)
{
if(partition.PartitionType == 0x0) continue; // Consider marked as free
PTR_PARTITION found_partition = (PARTITION*) malloc(sizeof(PARTITION));
found_partition->Disk = ATAPIO_PORT::Primary | ( DEVICE_DRIVE::MASTER << 16);
printf("Disk Identifier: 0x%x\n", found_partition->Disk);
found_partition->Attributes = partition.driveAttribute;
found_partition->StartAddress = partition.LBA_partition_start;
found_partition->Sectors = partition.Number_sectors_inPartition;
found_partition->Fs_hint = partition.PartitionType;
VirtualFileSystem::RegisterPartition(found_partition);
}
printf("Found %d partitions on disk!\n", num_partitions);
for (int i = 0; i < num_partitions; i++)
{
auto* partition = _partitions[i];
// Check the fs_hint for a proper driver
if ( partition->Fs_hint != 0x06){
printf("Assumed Unkown filesystem!\n");
continue;
}
// Check if filesystem OK
printf("Partition Start Address (LBA): 0x%x\n", partition->StartAddress);
bool valid = FAT::Validate(partition);
if(!valid)
{
printf("Not a valid FAT fs!\n");
continue;
}
// setup FileSystem Description before mounting
PFS FS_FAT = (PFS)malloc(sizeof(FILESYSTEM));
FAT::Info(partition, FS_FAT);
// Mount the partition/filesystem
Mount(FS_FAT , i);
}
};
void VirtualFileSystem::RegisterPartition(PTR_PARTITION partition) {
_partitions[num_partitions] = partition;
num_partitions++;
}
FILE VirtualFileSystem::OpenFile(const char* path)
{
// See reference material (1) https://man7.org/linux/man-pages/man7/path_resolution.7.html
unsigned char device = 'a';
char* filename = (char*)path;
char* cpy = filename;
if(filename[1] == ':'){
device = filename[0];
filename += 2;
}
if ( _filesystems[device - 'a']){
// Unfortunately this way the FAT Driver doesn't know which device and which partition to read from
// leaving us hopeless of finding the file.
FILE file = _filesystems[device-'a']->Open(filename);
file.device = device;
free(cpy);
return file;
}
free(cpy);
FILE file;
file.flags = FS_INVALID;
return file;
}
void VirtualFileSystem::Mount(PFS filesystemDescriptor, unsigned int DeviceID)
{
if(DeviceID < DEVICE_MAX)
if(filesystemDescriptor)
_filesystems[DeviceID] = filesystemDescriptor;
}
void VirtualFileSystem::Unmount(unsigned int DeviceID) {
if(DeviceID < DEVICE_MAX)
_filesystems[DeviceID] = nullptr;
}