* Added support to msdos partition table and fat32 file system

* Updated read28 function
* added new command lspt

Author: Arun007coder

Drivers/HDD-ATA.cpp

@@ -66,7 +66,7 @@ void AdvancedTechnologyAttachment::Identify()
     printf("\n");
 }
 
-void AdvancedTechnologyAttachment::Read28(uint32_t sectorNum, int count)
+void AdvancedTechnologyAttachment::Read28(uint32_t sectorNum, uint8_t* data, int count)
 {
     if(sectorNum > 0x0FFFFFFF)
         return;
@@ -93,19 +93,13 @@ void AdvancedTechnologyAttachment::Read28(uint32_t sectorNum, int count)
 
     printf("Reading ATA Drive: ");
 
-    for(int i = 0; i < count; i += 2)
+    for(uint16_t i = 0; i < count; i += 2)
     {
         uint16_t wdata = dataPort.ReadFromPort();
 
-        char *text = "  \0";
-        text[0] = wdata & 0xFF;
-
+        data[i] = wdata & 0x00FF;
         if(i+1 < count)
-            text[1] = (wdata >> 8) & 0xFF;
-        else
-            text[1] = '\0';
-
-        printf(text);
+            data[i+1] = (wdata >> 8) & 0x00FF;
     }    
 
     for(int i = count + (count%2); i < 512; i += 2)

Drivers/HDD-ATA.h

@@ -22,7 +22,7 @@ class AdvancedTechnologyAttachment
     AdvancedTechnologyAttachment(bool master, uint16_t portBase);
     ~AdvancedTechnologyAttachment();
     void Identify();
-    void Read28(uint32_t sectorNum, int count = 512);
+    void Read28(uint32_t sectorNum, uint8_t* data, int count = 512);
     void Write28(uint32_t sectorNum, uint8_t* data, uint32_t count);
     void Flush();
 };

Drivers/Keyboard.cpp

@@ -16,6 +16,7 @@ void detect_cpu();
 void PrintMEM(const void* multiboot_structure);
 void PrintSATA();
 void PVGA();
+void PrintPartitions();
 
 PowerControl power;
 
@@ -307,6 +308,8 @@ void KeyboardDriver::CommandInterpreter() // SOSH v1.0.3 [SectorOS SHell]. 11 Co
             printf("Help page 2:\nadd1 <num1> <num2> :To add 2 numbers.This command only supports 1 digit number\nsub1 <num1> <num2> :to subtract 2 numbers.This command only supports 1 digit number\ntxt : To enter the text mode. You cannot save files\nmul1 <num1> <num2> : To multiply 2 numbers.");
         else if (key_buffer[5] == "3")
             printf("Help page 3:\nspi : To print the data in serial port 0x3F8.\nspo : To write data to serial port 0x3F8.\nsysinfo [option] : To get info about system.\nvga : To use experimental vga graphics.");
+        else if (key_buffer[5] == "4")
+            printf("Help page 4:\nlspt: To list partitions in a drive.");
         else
             printf("Help page 1:\necho <message> : to print the message in the console \nhelp : to show this message \nclear : to clear the screen \nsd <options> : controls the power of the computer ");
     }
@@ -453,6 +456,11 @@ void KeyboardDriver::CommandInterpreter() // SOSH v1.0.3 [SectorOS SHell]. 11 Co
         COMNAME = "vga";
         PVGA();
     }
+    else if (key_buffer[0] == "l" && key_buffer[1] == "s" && key_buffer[2] == "p" && key_buffer[3] == "t")
+    {
+        COMNAME = "lspt";
+        PrintPartitions();
+    }
     else
     {
         printf("Unknown Command. Type help in console to get all the commands");

Filesystem/FATFS.cpp

@@ -0,0 +1,83 @@
+#include "FATFS.h"
+
+void printf(char*);
+void printHex(uint8_t Key);
+
+void ReadBiosBlock(AdvancedTechnologyAttachment *hd, uint32_t partitionOffset)
+{
+    BiosParameterBlock32 bpb;
+    hd->Read28(partitionOffset, (uint8_t*)&bpb, sizeof(BiosParameterBlock32));
+
+    
+    printf("sectors per cluster: ");
+    printHex(bpb.sectorsPerCluster);
+    printf("\n");
+    
+    
+    uint32_t fatStart = partitionOffset + bpb.reservedSectors;
+    uint32_t fatSize = bpb.tableSize;
+    
+    uint32_t dataStart = fatStart + fatSize*bpb.fatCopies;
+    
+    uint32_t rootStart = dataStart + bpb.sectorsPerCluster*(bpb.rootCluster - 2);
+    
+    
+    DirectoryEntryFat32 dirent[16];
+    hd->Read28(rootStart, (uint8_t*)&dirent[0], 16*sizeof(DirectoryEntryFat32));
+    
+    for(int i = 0; i < 16; i++)
+    {
+        if(dirent[i].name[0] == 0x00)
+            break;
+        
+        if((dirent[i].attributes & 0x0F) == 0x0F)
+            continue;
+        
+        char* foo = "        \n";
+        for(int j = 0; j < 8; j++)
+            foo[j] = dirent[i].name[j];
+        printf(foo);
+        
+        
+        if((dirent[i].attributes & 0x10) == 0x10) // directory
+            continue;
+        
+        uint32_t firstFileCluster = ((uint32_t)dirent[i].firstClusterHi) << 16
+                             | ((uint32_t)dirent[i].firstClusterLow);
+        
+        
+                             
+                             
+        int32_t SIZE = dirent[i].size;
+        int32_t nextFileCluster = firstFileCluster;
+        uint8_t buffer[513];
+        uint8_t fatbuffer[513];
+                             
+        
+        while(SIZE > 0)
+        {
+            uint32_t fileSector = dataStart + bpb.sectorsPerCluster * (nextFileCluster-2);
+            int sectorOffset = 0;
+        
+            for(; SIZE > 0; SIZE -= 512)
+            {
+                hd->Read28(fileSector+sectorOffset, buffer, 512);
+                
+                buffer[SIZE > 512 ? 512 : SIZE] = '\0';
+                printf((char*)buffer);
+                
+                if(++sectorOffset > bpb.sectorsPerCluster)
+                    break;
+            }
+            
+            uint32_t fatSectorForCurrentCluster = nextFileCluster / (512/sizeof(uint32_t));
+            hd->Read28(fatStart+fatSectorForCurrentCluster, fatbuffer, 512);
+            uint32_t fatOffsetInSectorForCurrentCluster = nextFileCluster % (512/sizeof(uint32_t));
+            nextFileCluster = ((uint32_t*)&fatbuffer)[fatOffsetInSectorForCurrentCluster] & 0x0FFFFFFF;
+            
+        }
+        
+    }
+
+    
+}

Filesystem/FATFS.h

@@ -0,0 +1,60 @@
+#ifndef __FATFS_H
+#define __FATFS_H
+
+#include "../Drivers/HDD-ATA.h"
+#include "../Includes/types.h"
+
+struct BiosParameterBlock32
+{
+    uint8_t jump[3];
+    uint8_t softName[8];
+    uint16_t bytesPerSector;
+    uint8_t sectorsPerCluster;
+    uint16_t reservedSectors;
+    uint8_t fatCopies;
+    uint16_t rootDirEntries;
+    uint16_t totalSectors;
+    uint8_t mediaType;
+    uint16_t fatSectorCount;
+    uint16_t sectorsPerTrack;
+    uint16_t headCount;
+    uint32_t hiddenSectors;
+    uint32_t totalSectorCount;
+    
+    uint32_t tableSize;
+    uint16_t extFlags;
+    uint16_t fatVersion;
+    uint32_t rootCluster;
+    uint16_t fatInfo;
+    uint16_t backupSector;
+    uint8_t reserved0[12];
+    uint8_t driveNumber;
+    uint8_t reserved;
+    uint8_t bootSignature;
+    uint32_t volumeId;
+    uint8_t volumeLabel[11];
+    uint8_t fatTypeLabel[8];
+} __attribute__((packed));
+        
+        
+struct DirectoryEntryFat32
+{
+    uint8_t name[8];
+    uint8_t ext[3];
+    uint8_t attributes;
+    uint8_t reserved;
+    uint8_t cTimeTenth;
+    uint16_t cTime;
+    uint16_t cDate;
+    uint16_t aTime;
+    uint16_t firstClusterHi;
+    uint16_t wTime;
+    uint16_t wDate;
+    uint16_t firstClusterLow;
+    uint32_t size;
+} __attribute__((packed));
+    
+    
+    void ReadBiosBlock(AdvancedTechnologyAttachment *hd, uint32_t partitionOffset);
+
+#endif

Filesystem/MSDOSPT.cpp

@@ -0,0 +1,52 @@
+#include "MSDOSPT.h"
+
+void printf(char*);
+void printHex(uint8_t);
+
+void MSDOSPartitionTable::ReadPartitions(AdvancedTechnologyAttachment *hd)
+{
+    
+    MasterBootRecord mbr;
+    
+    printf("MBR: ");
+    
+    hd->Read28(0, (uint8_t*)&mbr, sizeof(MasterBootRecord));
+
+    /*
+    for(int i = 0x1BE; i <= 0x01FF; i++)
+    {
+        printHex(((uint8_t*)&mbr)[i]);
+        printf(" ");
+    }
+    printf("\n");
+    */
+    
+    if(mbr.magicnumber != 0xAA55)
+    {
+        printf("illegal MBR");
+        return;
+    }
+    
+    
+    for(int i = 0; i < 4; i++)
+    {
+        if(mbr.primaryPartition[i].partition_id == 0x00)
+            continue;
+        
+        printf(" Partition ");
+        printHex(i & 0xFF);
+        
+        
+        if(mbr.primaryPartition[i].bootable == 0x80)
+            printf(" bootable. Type");
+        else
+            printf(" not bootable. Type ");
+        
+        
+        printHex(mbr.primaryPartition[i].partition_id);
+        
+     
+        ReadBiosBlock(hd, mbr.primaryPartition[i].start_lba);
+    }
+    
+}

Filesystem/MSDOSPT.h

@@ -0,0 +1,41 @@
+#ifndef __MSDOSPT_H
+#define __MSDOSPT_H
+
+#include "../Drivers/HDD-ATA.h"
+#include "../Includes/types.h"
+#include "FATFS.h"
+
+struct PartitionTableEntry
+{
+    uint8_t bootable;
+    uint8_t start_head;
+    uint8_t start_sector : 6;
+    uint16_t start_cylinder : 10;
+    uint8_t partition_id;
+    uint8_t end_head;
+    uint8_t end_sector : 6;
+    uint16_t end_cylinder : 10;
+    
+    uint32_t start_lba;
+    uint32_t length;
+} __attribute__((packed));
+
+struct MasterBootRecord
+{
+    uint8_t bootloader[440];
+    uint32_t signature;
+    uint16_t unused;
+    
+    PartitionTableEntry primaryPartition[4];
+    
+    uint16_t magicnumber;
+} __attribute__((packed));
+
+
+class MSDOSPartitionTable
+{
+public:
+    static void ReadPartitions(AdvancedTechnologyAttachment *hd);
+};
+
+#endif

Includes/Public_VAR.h

@@ -4,11 +4,11 @@
 inline char* OS_NAME = "SectorOS";
 
 inline char* KERNEL_NAME = "SectorOS";
-inline char* KERNEL_VERSION = "V1.5.0";
-inline char* KERNEL_BUILD = "Build: 2021-11-24";
+inline char* KERNEL_VERSION = "V2.1.0";
+inline char* KERNEL_BUILD = "Build: 2021-11-25";
 inline char* KERNEL_ARCH = "x86";
 
 inline char* SHELL_NAME = "SOSH";
-inline char* SHELL_VER = "V1.0.6";
+inline char* SHELL_VER = "V1.0.7";
 
 #endif

Makefile

@@ -16,6 +16,8 @@ Drivers/Keyboard.o \
 Drivers/HDD-ATA.o \
 Drivers/VGADriver.o \
 CPU/syscall.o \
+Filesystem/MSDOSPT.o \
+Filesystem/FATFS.o \
 Drivers/Mouse.o \
 Drivers/RTC.o \
 Hardcom/SerialPort.o \

kernel/kernel.cpp

@@ -14,6 +14,7 @@
 #include "../Includes/Debug.h"
 #include "../Drivers/HDD-ATA.h"
 #include "../Drivers/VGADriver.h"
+#include "../Filesystem/MSDOSPT.h"
 
 static uint8_t cursory;
 static uint8_t cursorx;
@@ -460,6 +461,12 @@ void printHex(uint8_t Key)
     printf(foo);
 }
 
+void PrintPartitions()
+{
+    AdvancedTechnologyAttachment ata0s(false, 0x1F0);
+    MSDOSPartitionTable::ReadPartitions(&ata0s);
+}
+
 void PrintMEM(const void* multiboot_structure)
 {
     uint32_t* memupper = (uint32_t*)(((size_t)multiboot_structure) + 8);
@@ -792,6 +799,14 @@ extern "C" void kernelMain(const void* multiboot_structure, uint32_t /*multiboot
 
     PrintSATA();
 
+    PrintPartitions();
+    
+    /*
+    AdvancedTechnologyAttachment ata0s(false, 0x1F0);
+    ata0s.Write28(4, (uint8_t*)"Hello There", 12);
+    ata0s.Flush();
+    */
+
     printf("Allocating Memory....\n");
 
     PrintMEM(multiboot_structure);
@@ -816,6 +831,8 @@ extern "C" void kernelMain(const void* multiboot_structure, uint32_t /*multiboot
 
     printf("Welcome to SectorOS Shell\nRun help to get the list of commands which is implemented \n \n");
 
+    //ata0s.Read28(4);
+
     sp.logToSerialPort("\nKernel initialization surcessful.\nGiving execution access to the kernel.\nAwaiting user input...");
 
     printf("$: ");