Reading from the FAT12-formatted floppy works \o

8 files changed, 374 insertions, 3 deletions

diff --git a/Source/Kernel/Core/Sys.ns.h b/Source/Kernel/Core/Sys.ns.h
index 4d15676..9b34dbf 100644
--- a/Source/Kernel/Core/Sys.ns.h
+++ b/Source/Kernel/Core/Sys.ns.h
@@ -18,9 +18,12 @@
 
 //This file contains system-relative functions
 class String;
+class SimpleVT;
 class VirtualTerminal;
 struct registers_t;
 
+extern SimpleVT* kvt;
+
 namespace Sys {
 	void outb(u16int port, u8int value);
 	u8int inb(u16int port);
diff --git a/Source/Kernel/Core/kmain.wtf.cpp b/Source/Kernel/Core/kmain.wtf.cpp
index d0751d1..bb77eeb 100644
--- a/Source/Kernel/Core/kmain.wtf.cpp
+++ b/Source/Kernel/Core/kmain.wtf.cpp
@@ -25,6 +25,7 @@
 #include <Rand.ns.h>
 #include <VFS/Part.ns.h>
 #include <FileSystems/RamFS/RamFS.class.h>
+#include <FileSystems/FAT/FATFS.class.h>
 #include <VFS/FileNode.class.h>
 #include <VFS/VFS.ns.h>
 #include <VFS/DirectoryNode.class.h>
@@ -37,6 +38,8 @@ extern u32int end;	//Placement address
 
 extern "C" void kmain(multiboot_info_t* mbd, u32int magic);
 
+SimpleVT* kvt;
+
 u32int logoAnimation(void* p) {
 	SimpleVT& vt = *((SimpleVT*)p);
 	vt.setColor(8);
@@ -140,7 +143,7 @@ void kmain(multiboot_info_t* mbd, u32int magic) {
 	Disp::setText(vgaout);
 
 	//Create a VT for logging what kernel does
-	SimpleVT *kvt = new ScrollableVT(25, 80, 20, KVT_FGCOLOR, KVT_BGCOLOR);
+	kvt = new ScrollableVT(25, 80, 20, KVT_FGCOLOR, KVT_BGCOLOR);
 	kvt->map(0, 0);
 	*kvt << "Melon is loading...";
 
@@ -187,6 +190,8 @@ void kmain(multiboot_info_t* mbd, u32int magic) {
 	cwd = VFS::getRootNode();
 	Task::currProcess()->setCwd(cwd);
 
+	FATFS::mount(Part::partitions[0], (DirectoryNode*)VFS::createDirectory("/Mount"));
+
 	if (keymap != "builtin") {
 		if (!Kbd::loadKeymap(keymap)) *kvt << "\nWARNING : Could not load keymap " << keymap << ", using built-in keymap instead.";
 	}
diff --git a/Source/Kernel/FileSystems/FAT/FATDirectoryNode.class.h b/Source/Kernel/FileSystems/FAT/FATDirectoryNode.class.h
new file mode 100644
index 0000000..c2f55e1
--- /dev/null
+++ b/Source/Kernel/FileSystems/FAT/FATDirectoryNode.class.h
@@ -0,0 +1,16 @@
+#ifndef DEF_FATDIRECTORYNODE_CLASS_H
+#define DEF_FATDIRECTORYNODE_CLASS_H
+
+#include <VFS/DirectoryNode.class.h>
+
+class FATDirectoryNode : public DirectoryNode {
+	friend class FATFS;
+	FATDirectoryNode(String name, FileSystem* fs, FSNode* parent, u32int permissions = 0777,
+			u32int uid = 0, u32int gid = 0) :
+			DirectoryNode(name, fs, parent, permissions, uid, gid) {}
+
+	u32int m_firstCluster;
+	u32int m_firstDirEntryID;	//id of the first directory entry corresponding to this file in parent directory
+};
+
+#endif
diff --git a/Source/Kernel/FileSystems/FAT/FATFS.class.cpp b/Source/Kernel/FileSystems/FAT/FATFS.class.cpp
new file mode 100644
index 0000000..2590785
--- /dev/null
+++ b/Source/Kernel/FileSystems/FAT/FATFS.class.cpp
@@ -0,0 +1,201 @@
+#include "FATFS.class.h"
+#include <VTManager/SimpleVT.class.h>
+#include "FATFileNode.class.h"
+#include "FATDirectoryNode.class.h"
+#include <VFS/VFS.ns.h>
+
+#define FIRSTCLUS(node) ((u32int&)(node->type() == NT_DIRECTORY ? \
+			((FATDirectoryNode*)(node))->m_firstCluster : \
+			((FATFileNode*)(node))->m_firstCluster))
+#define FIRSTDEID(node) ((u32int&)(node->type() == NT_DIRECTORY ? \
+			((FATDirectoryNode*)(node))->m_firstDirEntryID : \
+			((FATFileNode*)(node))->m_firstDirEntryID))
+
+FATFS* FATFS::mount(Partition* p, DirectoryNode* mountpoint) {
+	if (mountpoint != 0 and !mountpoint->mountpointable()) return 0;
+	//		***	READ BOOT SECTOR ***
+	union {
+		fat_BS_t s;
+		u8int c[512];
+	} bs;
+	p->readBlocks(0, 1, bs.c);
+	//		*** CHECK FILESYSTEM TYPE ***
+	if (bs.s.extBS_16.boot_signature != 0x28 and bs.s.extBS_16.boot_signature != 0x29
+			and bs.s.extBS_32.boot_signature != 0x28 and bs.s.extBS_32.boot_signature != 0x29) return 0;
+	//		*** DO SOME CALCULATIONS ***
+	FATFS* fs = new FATFS();
+	fs->m_fatSize = (bs.s.table_size_16 == 0 ? bs.s.extBS_32.table_size_32 : bs.s.table_size_16);
+	fs->m_totalSectors = (bs.s.total_sectors_16 == 0 ? bs.s.total_sectors_32 : bs.s.total_sectors_16);
+	fs->m_rootDirSectors = ((bs.s.root_entry_count * 32) + (bs.s.bytes_per_sector - 1)) / bs.s.bytes_per_sector;
+	fs->m_firstDataSector = bs.s.reserved_sector_count + (fs->m_fatSize * bs.s.table_count);
+	fs->m_clusterSize = bs.s.bytes_per_sector * bs.s.sectors_per_cluster;
+	u32int dataSectors = fs->m_totalSectors - (fs->m_firstDataSector + fs->m_rootDirSectors);
+	fs->m_countOfClusters = dataSectors / bs.s.sectors_per_cluster;
+	if (fs->m_countOfClusters < 4085) {	//Find out FAT type
+		fs->m_fatType = 12;
+	} else if (fs->m_countOfClusters < 65525) {
+		fs->m_fatType = 16;
+	} else {
+		fs->m_fatType = 32;
+	}
+	fs->m_readOnly = true;
+	fs->m_bs = bs.s;
+	fs->m_part = p;
+	//		*** CREATE ROOT DIRECTORY NODE ***
+	fs->m_rootNode = new FATDirectoryNode("/", fs, mountpoint);
+	FIRSTCLUS(fs->m_rootNode) = 2;
+	if (fs->m_fatType == 32) FIRSTCLUS(fs->m_rootNode) = bs.s.extBS_32.root_cluster;
+	if (mountpoint != 0) mountpoint->mount(fs->m_rootNode);
+	VFS::registerFilesystem(fs);
+	*kvt << "\nDetected a FAT" << (s64int)fs->m_fatType << " filesystem.\n" <<
+		"root_dir_sectors:" << fs->m_rootDirSectors << " fat_size:" << fs->m_fatSize << " total_sectors:" <<
+		fs->m_totalSectors << " data_sectors:" << dataSectors << " count_of_clusters:" << fs->m_countOfClusters <<
+		" sizeof(fat_dir_entry_t):" << sizeof(fat_dir_entry_t) << " first_data_sector:" << fs->m_firstDataSector;
+	return 0;
+}
+
+u32int FATFS::nextCluster(u32int cluster) {
+	u8int fat_table[m_part->getBlockSize()];
+	u32int val;
+	if (m_fatType == 12) {
+		u32int fat_offset = cluster + (cluster / 2);
+		u32int fat_sector = m_bs.reserved_sector_count + (fat_offset / m_part->getBlockSize());
+		u32int ent_offset = fat_offset % m_part->getBlockSize();
+		m_part->readBlocks(fat_sector, 1, fat_table);
+		u16int tblval = *(u16int*)&fat_table[ent_offset];
+		if (cluster & 1) val = tblval >> 4;
+		else val = tblval & 0x0FFF;
+		if (val >= 0xFF7) val = 0;
+	} else if (m_fatType == 16) {
+		u32int fat_offset = cluster * 2;
+		u32int fat_sector = m_bs.reserved_sector_count + (fat_offset / m_part->getBlockSize());
+		u32int ent_offset = fat_offset % m_part->getBlockSize();
+		m_part->readBlocks(fat_sector, 1, fat_table);
+		u16int tblval = *(u16int*)&fat_table[ent_offset];
+		val = tblval;
+		if (tblval >= 0xFFF7) val = 0;
+	} else if (m_fatType == 32) {
+		u32int fat_offset = cluster * 4;
+		u32int fat_sector = m_bs.reserved_sector_count + (fat_offset / m_part->getBlockSize());
+		u32int ent_offset = fat_offset % m_part->getBlockSize();
+		m_part->readBlocks(fat_sector, 1, fat_table);
+		val = *(u32int*)&fat_table[ent_offset] & 0x0FFFFFFF;
+		if (val >= 0x0FFFFFF7) val = 0;
+	}
+	return val;
+}
+
+void FATFS::readCluster(u32int cluster, u8int* data) {
+	u32int firstSector = ((cluster - 2) * m_bs.sectors_per_cluster) + m_firstDataSector;
+	if (cluster > 2 and m_fatType != 32) firstSector += m_rootDirSectors;
+	m_part->readBlocks(firstSector, m_bs.sectors_per_cluster, data);
+}
+
+bool FATFS::unmount() {
+	if (m_readOnly) return true;
+	return false;
+}
+
+bool FATFS::setName(FSNode* node, String name) {
+	if (m_readOnly) return false;
+	return false;
+}
+
+bool FATFS::setPermissions(FSNode* node, u32int permissions) {
+	if (m_readOnly) return false;
+	return false;
+}
+
+bool FATFS::setUid(FSNode* node, u32int uid) {
+	if (m_readOnly) return false;
+	return false;
+}
+
+bool FATFS::setGid(FSNode* node, u32int gid) {
+	if (m_readOnly) return false;
+	return false;
+}
+
+bool FATFS::setParent(FSNode* node, FSNode* parent) {
+	if (m_readOnly) return false;
+	return false;
+}
+
+u32int FATFS::read(FileNode* file, u64int position, u32int max_length, u8int *data) {
+	return 0;
+}
+
+bool FATFS::write(FileNode* file, u64int position, u32int length, u8int* data) {
+	if (m_readOnly) return false;
+	return false;
+}
+
+bool FATFS::truncate(FileNode* file) {
+	if (m_readOnly) return false;
+	return false;
+}
+
+bool FATFS::loadContents(DirectoryNode* dir) {
+	u32int cluster = FIRSTCLUS(dir);
+	union {
+		u8int *c;
+		fat_dir_entry_t *e;
+	} e;
+
+	u32int entries = m_clusterSize / sizeof(fat_dir_entry_t);
+	if (cluster == 2 and m_fatType != 32) {		//This is the value we use for the root directory
+		e.c = (u8int*)Mem::alloc(m_rootDirSectors * m_part->getBlockSize());
+		m_part->readBlocks(m_firstDataSector, m_rootDirSectors, e.c);
+	} else {
+		e.c = (u8int*)Mem::alloc(m_clusterSize);
+	}
+
+	while (cluster != 0) {
+		if (cluster != 2 or m_fatType == 32) readCluster(cluster, e.c);
+		for (u32int i = 0; i < entries; i++) {
+			if (e.e[i].name[0] == 0 or e.e[i].name[0] == 0xE5) continue;	//Nothing intresting here.
+			if (e.e[i].attributes == FA_LFN) continue;	//Long file name entry, nothing intresting
+			if (e.e[i].attributes & FA_VOLUMEID) continue;
+			String name;
+			for (int j = 0; j < 8; j++) {
+				if (e.e[i].name[j] == ' ') break;
+				name += WChar(e.e[i].name[j]);
+			}
+			for (int j = 0; j < 3; j++) {
+				if (e.e[i].extension[j] == ' ') break;
+				if (j == 0) name += ".";
+				name += WChar(e.e[i].extension[j]);
+			}
+			u32int first_clus = (e.e[i].first_clust_high << 16) + e.e[i].first_clust_low;
+			FSNode* n;
+			if (e.e[i].attributes & FA_DIRECTORY) {
+				if (name == "." or name == "..") continue;
+				n = new FATDirectoryNode(name, this, dir);
+			} else {
+				n = new FATFileNode(name, this, dir, e.e[i].size);
+			}
+			FIRSTCLUS(n) = first_clus;
+			dir->getChildren().push(n);
+		}
+		if (cluster == 2 && m_fatType != 32) break;	//We are in a FAT12/16 root directory
+		cluster = nextCluster(cluster);
+	}
+
+	Mem::free(e.c);
+	return true;
+}
+
+FileNode* FATFS::createFile(DirectoryNode* parent, String name) {
+	if (m_readOnly) return false;
+	return 0;
+}
+
+DirectoryNode* FATFS::createDirectory(DirectoryNode* parent, String name) {
+	if (m_readOnly) return false;
+	return 0;
+}
+
+bool FATFS::remove(DirectoryNode* parent, FSNode* node) {
+	if (m_readOnly) return false;
+	return false;
+}
diff --git a/Source/Kernel/FileSystems/FAT/FATFS.class.h b/Source/Kernel/FileSystems/FAT/FATFS.class.h
new file mode 100644
index 0000000..50ff479
--- /dev/null
+++ b/Source/Kernel/FileSystems/FAT/FATFS.class.h
@@ -0,0 +1,130 @@
+#ifndef DEF_FATFS_CLASS_H
+#define DEF_FATFS_CLASS_H
+
+#include <VFS/FileSystem.proto.h>
+#include <VFS/Part.ns.h>
+
+struct fat_extBS_32_t {			//Extended boot sector for FAT32
+	unsigned int		table_size_32;
+	unsigned short		extended_flags;
+	unsigned short		fat_version;
+	unsigned int		root_cluster;
+	unsigned short		fat_info;
+	unsigned short		backup_BS_sector;
+	unsigned char 		reserved_0[12];
+	unsigned char		drive_number;
+	unsigned char 		reserved_1;
+	unsigned char		boot_signature;
+	unsigned int 		volume_id;
+	unsigned char		volume_label[11];
+	unsigned char		fat_type_label[8];
+}__attribute__((packed));
+
+struct fat_extBS_16_t {	//Extended boot sector for FAT12 and FAT16
+	unsigned char		bios_drive_num;
+	unsigned char		reserved1;
+	unsigned char		boot_signature;
+	unsigned int		volume_id;
+	unsigned char		volume_label[11];
+	unsigned char		fat_type_label[8];
+}__attribute__((packed));
+
+struct fat_BS_t {		//Boot sector
+	unsigned char 		bootjmp[3];
+	unsigned char 		oem_name[8];
+	unsigned short 	        bytes_per_sector;
+	unsigned char		sectors_per_cluster;
+	unsigned short		reserved_sector_count;
+	unsigned char		table_count;
+	unsigned short		root_entry_count;
+	unsigned short		total_sectors_16;
+	unsigned char		media_type;
+	unsigned short		table_size_16;
+	unsigned short		sectors_per_track;
+	unsigned short		head_side_count;
+	unsigned int 		hidden_sector_count;
+	unsigned int 		total_sectors_32;
+	union {
+		fat_extBS_32_t	extBS_32;
+		fat_extBS_16_t	extBS_16;
+	};
+}__attribute__((packed));
+
+struct fat_date_t {
+	u16int year		: 7;
+	u16int month	: 4;
+	u16int day		: 5;
+}__attribute__((packed));
+
+struct fat_time_t {
+	u16int hour		: 5;
+	u16int minutes	: 6;
+	u16int seconds	: 5;
+}__attribute__((packed));
+
+struct fat_dir_entry_t {
+	char name[8];
+	char extension[3];
+	u8int attributes;
+	u8int reserved;
+	u8int createtenthsofseconds;
+	fat_time_t created_time;
+	fat_date_t created_date;
+	fat_date_t accessed_date;
+	u16int first_clust_high;	//always 0 on FAT12/16
+	fat_time_t modified_time;
+	fat_date_t modified_date;
+	u16int first_clust_low;
+	u32int size;
+}__attribute__((packed));
+
+#define FA_READONLY 0x01
+#define FA_HIDDEN 0x02
+#define FA_SYSTEM 0x04
+#define FA_VOLUMEID 0x08
+#define FA_DIRECTORY 0x10
+#define FA_ARCHIVE 0x20
+#define FA_LFN 0x0F
+
+class FATFS : public FileSystem {
+	private:
+	FATFS() {}
+	~FATFS() {}
+
+	fat_BS_t m_bs;
+	bool m_readOnly;
+	u32int m_fatSize;	//Size of one FAT, in sectors
+	u32int m_totalSectors;	//Total sectors used by the FAT
+	u32int m_rootDirSectors;	//Sectors used by the root directory
+	u32int m_firstDataSector;	//First data sector, start of cluster 2
+	u32int m_countOfClusters;	//Count of usable clusters, EXCLUDING the ones used by the root directory
+	u32int m_clusterSize;	//size of a cluster in bytes
+	u32int m_fatType;	//12, 16 or 32
+	Partition* m_part;
+
+	u32int nextCluster(u32int cluster);		//Get the next cluster number in the chain (0 = EOF)
+	void readCluster(u32int cluster, u8int* data);	//Read the content of a cluster to a buffer
+	
+	public:
+	static FATFS* mount(Partition* p, DirectoryNode* mountpoint);
+
+	bool unmount();
+
+	bool setName(FSNode* node, String name);
+	bool setPermissions(FSNode* node, u32int permissions);
+	bool setUid(FSNode* node, u32int uid);
+	bool setGid(FSNode* node, u32int gid);
+	bool setParent(FSNode* node, FSNode* parent);
+
+	u32int read(FileNode* file, u64int position, u32int max_length, u8int *data);
+	bool write(FileNode* file, u64int position, u32int length, u8int *data);
+	bool truncate(FileNode* file);
+
+	bool loadContents(DirectoryNode* dir);
+	FileNode* createFile(DirectoryNode* parent, String name);
+	DirectoryNode* createDirectory(DirectoryNode* parent, String name);
+	bool remove(DirectoryNode* parent, FSNode* node);
+};
+
+#endif
+
diff --git a/Source/Kernel/FileSystems/FAT/FATFileNode.class.h b/Source/Kernel/FileSystems/FAT/FATFileNode.class.h
new file mode 100644
index 0000000..b64f911
--- /dev/null
+++ b/Source/Kernel/FileSystems/FAT/FATFileNode.class.h
@@ -0,0 +1,16 @@
+#ifndef DEF_FATFILENODE_CLASS_H
+#define DEF_FATFILENODE_CLASS_H
+
+#include <VFS/FileNode.class.h>
+
+class FATFileNode : public FileNode {
+	friend class FATFS;
+	FATFileNode (String name, FileSystem* fs, FSNode* parent, u32int size, u32int permissions = 0777,
+			u32int uid = 0, u32int gid = 0) :
+		FileNode(name, fs, parent, size, permissions, uid, gid){}
+
+	u32int m_firstCluster;
+	u32int m_firstDirEntryID;	//id of the first directory entry corresponding to this file in parent directory
+};
+
+#endif
diff --git a/Source/Kernel/Makefile b/Source/Kernel/Makefile
index a70c8c5..2005cd2 100644
--- a/Source/Kernel/Makefile
+++ b/Source/Kernel/Makefile
@@ -66,6 +66,7 @@ Objects = Core/loader.wtf.o \
 		VFS/DirectoryNode.class.o \
 		UserManager/Usr.ns.o \
 		FileSystems/RamFS/RamFS.class.o \
+		FileSystems/FAT/FATFS.class.o \
 		SyscallManager/IDT.ns.o \
 		SyscallManager/Ressource.class.o \
 		SyscallManager/Res.ns.o \
diff --git a/Source/Kernel/Shell/KernelShell.class.cpp b/Source/Kernel/Shell/KernelShell.class.cpp
index 8f71b9f..7f57f8b 100644
--- a/Source/Kernel/Shell/KernelShell.class.cpp
+++ b/Source/Kernel/Shell/KernelShell.class.cpp
@@ -128,8 +128,7 @@ u32int KernelShell::run() {
 					String p = VFS::path(n);
 					for (u32int i = 0; i < VFS::filesystems.size(); i++) {
 						if (VFS::path(VFS::filesystems[i]->getRootNode()) == p) {
-							VFS::unmount(VFS::filesystems[i]);
-							ok = true;
+							ok = VFS::unmount(VFS::filesystems[i]);
 							break;
 						}
 					}