Makefile

@@ -5,7 +5,7 @@ CC = ${HOME}/opt/cross/bin/i686-elf-gcc
 CPP = ${HOME}/opt/cross/bin/i686-elf-g++ 
 CFLAGS =  -ffreestanding -O2 -Wall -Wextra
 
-OFILES =	$(BUILD_DIR)/boot.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/io.o $(BUILD_DIR)/MMU.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o
+OFILES =	$(BUILD_DIR)/boot.o $(BUILD_DIR)/kterm.o $(BUILD_DIR)/kernel.o $(BUILD_DIR)/io.o $(BUILD_DIR)/MMU.o $(BUILD_DIR)/idt.o $(BUILD_DIR)/pic.o $(BUILD_DIR)/string.o
 
 SRC_DIR = src
 BUILD_DIR = build
@@ -79,3 +79,6 @@ $(BUILD_DIR)/idt.o:
 
 $(BUILD_DIR)/pic.o:
 	$(CPP) -c $(SRC_DIR)/kernel/arch/i386/pic/pic.cpp -o $(BUILD_DIR)/pic.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+$(BUILD_DIR)/string.o:
+	$(CC) -c $(SRC_DIR)/libc/include/string.c  -o $(BUILD_DIR)/string.o $(CFLAGS) -std=gnu99

src/kernel/MMU.cpp

@@ -1,4 +1,5 @@
 #include "MMU.h"
+#include <stdint.h>
 
 
 
@@ -34,8 +35,13 @@ void MMU::enable(){
     enablePaging();
 }
 
-
-uint32_t MMU::readTableEntry(int entry){
-    return this->page_directory[entry];
-
+/*
+void IdentityPaging(uint32_t *first_pte, vaddr from, int size)
+{
+    from = from & 0xFFFFF000; // Discard the bits we don't want
+    for (; size > 0; from += 4096, first_pte++)
+    {
+        *first_pte = from | 1; // makr page present.
     }
+}
+*/

src/kernel/MMU.h

@@ -1,13 +1,26 @@
 #pragma once 
 #include <stdint.h>
 
-extern "C" void loadPageDirectory (long unsigned int* addr );
+extern "C" void loadPageDirectory (uint32_t* addr );
 extern "C" void enablePaging();
+typedef uintptr_t address_t;
+
+
+#define KB 1024
+
+static const int MAX_PAGES =  1024 * KB; // 4GB , 4kB/page
+static volatile address_t pmem_stack[MAX_PAGES];
+static volatile address_t pmem_stack_top = MAX_PAGES; // top down allocation
+
+
+struct page_directory_entry {};
+struct page_table_entry{};
+
+
 
 class MMU {
     public:
     void enable ();
-    uint32_t readTableEntry(int);
     
     private:
     uint32_t page_directory[1024] __attribute__((aligned(4096)));

src/kernel/arch/i386/boot.s

@@ -21,7 +21,6 @@ stack_bottom:
 stack_top:
  
 .section .text
-
 /*
 * Interupt handlers
 */
@@ -469,7 +468,7 @@ loadPageDirectory:
 .type _start, @function
 _start:
 	/*Setup the stack pointer to point to the beginning of our stack */
-	/* I believe its a hight address growing down to lower adress for the stack on x86*/
+	/* I believe its a high address growing down to lower adress for the stack on x86*/
 	mov $stack_top, %esp
 
 	/*Reset EFLAGS*/
@@ -484,6 +483,7 @@ _start:
 	
 	call early_main
 	cli
+	
 	load_gdt:
 		lgdt gdt
 

src/kernel/arch/i386/gdt/gdtc.cpp

@@ -1,5 +1,5 @@
 #include "gdtc.h"
-
+#include "../tty/kterm.h"
  
 gdtEntry_t gdt[3];
 
@@ -18,6 +18,8 @@ void gdtSetGate(int num, uint64_t base, uint64_t limit, uint8_t access,
 }
 
 void setupGdt(){
+
+   printf("setupGdt is called!");
    gdtPointer.limit   = (sizeof(gdtEntry_t) * 3) - 1;
    gdtPointer.base    = &gdt;
 

src/kernel/arch/i386/gdt/gdtc.h

@@ -1,5 +1,5 @@
 #include <stdint.h>
-extern "c"{
+extern "C"{
 
 typedef struct {
    uint16_t           lLimit;

src/kernel/arch/i386/idt/idt.cpp

@@ -44,7 +44,7 @@ void irq_handler (registers regs) {
             // Keyboard interrupt !!
 
             int scan;
-            register int i;
+            /*register*/int i;
 
             // Read scancode 
 

src/kernel/arch/i386/idt/idt.h

@@ -8,7 +8,6 @@
 extern "C"{
     #include "../tty/kterm.h"
 }
-#define AS_KERNEL() (  kterm_writestring("[KERNEL]:"))
 
 
 extern "C" {

src/kernel/arch/i386/linker.ld

@@ -6,10 +6,11 @@ ENTRY(_start)
    kernel image. */
 SECTIONS
 {
+	
 	/* Begin putting sections at 1 MiB, a conventional place for kernels to be
 	   loaded at by the bootloader. */
 	. = 1M;
- 
+ 	kernel_begin = .;
 	/* First put the multiboot header, as it is required to be put very early
 	   early in the image or the bootloader won't recognize the file format.
 	   Next we'll put the .text section. */
@@ -40,4 +41,7 @@ SECTIONS
  
 	/* The compiler may produce other sections, by default it will put them in
 	   a segment with the same name. Simply add stuff here as needed. */
+
+	kernel_end = .;
 }
+

src/kernel/arch/i386/pic/pic.h

@@ -49,7 +49,7 @@ void PIC_sendEOI (unsigned char irq);
 }
 
 
-static uint16_t __pic_get_irq_reg(int ocw3);
+//static uint16_t __pic_get_irq_reg(int ocw3);
 uint16_t pic_get_irr(void);
 uint16_t pic_get_isr(void);
 

src/kernel/arch/i386/tty/kterm.c

@@ -1,4 +1,5 @@
 #include "kterm.h"
+
 static const size_t VGA_WIDTH = 80;
 static const size_t VGA_HEIGHT = 25;
 
@@ -201,8 +202,10 @@ void printf ( const char *format, ...) {
             switch (c)
             {
             case 'd':
-
+                kterm_writestring("Not implemented!!");
+                break;
             case 'u':
+                break;
             case 'x':
                 itoa(buf, c, *((int *) arg++));
 

src/kernel/arch/i386/tty/kterm.h

@@ -6,6 +6,10 @@
 
 #include "../vga/colors.h"
 #include "../../../io.h"
+
+
+#include "./../../../../libc/include/string.h"
+
 void kterm_init();
 
 /* Kernel terminal - Colour functions*/
@@ -31,7 +35,7 @@ int get_cursor_y (uint16_t cursor_pos);
 
 void printf ( const char *format, ...);
 
-static void itoa (char *buf, int base, int d);
+//static void itoa (char *buf, int base, int d);
 
 #define KernelTag "[Kernel]: "
 #define AS_KERNEL() (  kterm_setcolor(VGA_COLOR_LIGHT_BLUE),\

src/kernel/bootcheck.h

@@ -33,7 +33,7 @@ void CheckMBT ( multiboot_info_t*  mbt  ){
         /* Are mods_* valid? */
         if(CHECK_FLAG ( mbi->flags, 3)){
             multiboot_module_t *mod;
-            int i;
+            uint32_t i;
 
             printf("mods count = %d, mods_addr = 0x%x\n", (int) mbi->mods_count, (int) mbi->mods_addr);
 

src/kernel/cpu.h

@@ -1,6 +1,6 @@
 #include <cpuid.h> // NOTE: Only available in GCC 
-
-    static int get_model(){
+// NOT currently usefull!
+/*    static int get_model(){
         int ebx, unused;
         __cpuid(0, unused, ebx, unused, unused);
         return ebx;
@@ -14,3 +14,4 @@
         __get_cpuid(1, &eax, &unused, &unused, &edx);
         return  edx & CPUID_FEAT_EDX_APIC;
     }
+*/

src/kernel/disk.h

@@ -0,0 +1,17 @@
+#pragma once
+
+// Let's write an ATA PIO | ATA driver for now. Mostly to show that I can in theory interact with a
+// storage device
+
+// PRIMARY_ATA_BUS
+// 0x1F0 through 0x1F7 
+
+// SECONDARY_ATA_BUS
+// 0x170 through 0x177
+
+#define DEVICE_CONTROL_REGISTER 0x3F6
+#define DEVICE_CONTROL_ALTERNATE 0x376
+
+
+// IRQ14 Primary bus interrupt
+// IRQ15 Secondary bus interrupt

src/kernel/io.cpp

@@ -1,19 +1,24 @@
 #include "io.h"
 
 unsigned char inb_p(unsigned short ){
-
+        // TODO: implement me!
+        return 0;
 }
 unsigned short inw(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 unsigned short inw_p(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 unsigned int inl(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 unsigned int inl_p(unsigned short ){
-
+// TODO: implement me!
+        return 0;
 }
 
 

src/kernel/kernel.cpp

@@ -23,11 +23,20 @@ extern "C" {
         /* Are mmap_* valid? */
         if (CHECK_FLAG(mbt->flags, 6)){
             multiboot_memory_map_t *mmap = (multiboot_memory_map_t*) mbt->mmap_addr;
+            uint32_t memorySizeInBytes = 0;
+            uint32_t reservedMemoryInBytes = 0;
+
 
             printf("mmap_addr = 0x%x, mmap_length = 0x%x\n",
             (unsigned) mbt->mmap_addr, (unsigned) mbt->mmap_length);
             
-            for (mmap;  (unsigned long) mmap < mbt->mmap_addr + mbt->mmap_length;  mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size))){
+            for (;  (unsigned long) mmap < mbt->mmap_addr + mbt->mmap_length;  mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size))){
+                    if ( mmap->type == MULTIBOOT_MEMORY_AVAILABLE){
+                        memorySizeInBytes +=  mmap->len;   
+                    } else {
+                        reservedMemoryInBytes += mmap->len;
+                    }
+
 
                     printf(
                         "size = 0x%x, base_addr = 0x%x%08x, length = 0x%x%08x, type = 0x%x\n",
@@ -39,17 +48,31 @@ extern "C" {
                         (unsigned) mmap->type);
                 
                 }
+            uint32_t memorySizeInGiB = memorySizeInBytes / 1073741824; 
             
+            printf("Available Memory: 0x%x bytes, 0x%x GiB\n",  memorySizeInBytes, memorySizeInGiB );
+            printf("Reserved Memory: 0x%x bytes\n",  reservedMemoryInBytes );
         }
         
+       
+
+       //int cpu_model = get_model();
+       //int local_apic = check_apic();
+       //printf( "CPU Model: %x, Local APIC: %D\n", cpu_model, local_apic);
+
+
+     /* Setup Paging and memory Managment*/
+        //MMU  MemoryManagementUnit = MMU();
+        //MemoryManagementUnit.enable(); // Warning: Causes triple page fault
+        //printf("Pages available: %9d\n", pmm_available());
+
         /* Draw diagonal blue line */
-        if (CHECK_FLAG (mbi->flags, 12)){
+        if (CHECK_FLAG (mbt->flags, 12)){
             printf("Can draw!");
         } 
 
-        int cpu_model = get_model();
-        int local_apic = check_apic();
-        printf( "CPU Model: %x, Local APIC: %D\n", cpu_model, local_apic);
+        //setupGdt();
+
        
     }
 
@@ -57,19 +80,12 @@ extern "C" {
 
         init_serial();
 
-
-
-
-
-        while (true){
+        while (false){
             //Read time indefinetely 
             read_rtc();
             printf( "UTC time: %02d-%02d-%02d %02d:%02d:%02d  [ Formatted as YY-MM-DD h:mm:ss]\r" ,year, month, day, hour, minute, second);
             delay(1000);
         }
        
-
-       
-       
     }   
 }

src/kernel/kernel.h

@@ -1,10 +1,11 @@
 #pragma once 
 extern "C" {
-    #include "../libc/include/string.h"
+
     #include "arch/i386/tty/kterm.h"
     #include "pmm.h"
 }
 
+#include "../libc/include/string.h"
 #include "multiboot.h"
 #include "bootcheck.h"
 #include "arch/i386/idt/idt.h"

src/kernel/pci.cpp

@@ -0,0 +1,108 @@
+#include "pci.h"
+
+uint16_t ConfigReadWord (uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset){
+    uint32_t address;
+    uint32_t lbus = (uint32_t) bus;
+    uint32_t lslot = (uint32_t) slot;
+    uint32_t lfunc = (uint32_t) func;
+    uint16_t tmp = 0;
+
+    /* Create configuration address as per Figure 1 */
+    address = (uint32_t) ((lbus << 16) |  (lslot << 11) | (lfunc << 8) | (offset & 0xFC) |((uint32_t) 0x80000000) );
+    /*write out the address */ 
+    outl(CONFIG_ADDRESS, address);
+    /* read in the data */
+    /* (offset & 2 ) * 8 ) = o will choosse the first word of the 32 bits register*/
+    tmp = (uint16_t)((inl(CONFIG_DATA)) >> ((offset & 2) * 8) & 0xFFFF);
+    return (tmp);
+}
+
+uint16_t CheckVendor (uint8_t bus, uint8_t slot) {
+    uint16_t vendor, device;
+    /* 
+        Try and read the first configuration register. Since there ar no
+        vendors that == 0xFFFF, it must be a non-existent device.
+    */
+   if((vendor = ConfigReadWord(bus, slot, 0,0)) != 0xFFFF) {
+       device = ConfigReadWord(bus, slot, 0,2);
+        // Possible read more config values ...
+   } return (vendor);
+}
+
+void checkDevice (uint8_t bus, uint8_t device ) {
+    uint8_t function = 0;
+
+    uint16_t vendorID = CheckVendor(bus, device);
+    if (vendorID == 0xFFFF) {
+        return;
+    }
+
+    checkFunction (bus, device, function );
+    headerType = getHeaderType(bus, device, function );
+    if( (headerType & 0x80) != 0) {
+        /* It is  a multi-function device, so check remaining functions */
+        for (function = 1; function < 8; function++){
+            if (CheckVendor(bus, device)!= 0xFFFF){
+                checkFunction(bus, device, function );
+            } 
+        }
+    }
+
+}
+
+
+void checkFunction (uint8_t bus, uint8_t device, uint8_t function ){
+    uint8_t baseClass;
+    uint8_t subClass;
+    uint8_t secondaryBus;
+
+    baseClass = getBaseClass(bus, device, function);
+    subClass = getSubClass (bus, device, function );
+    if ( (baseClass == 0x06) && (subClass == 0x04)){
+        secondaryBus = getSecondaryBus(bus,device, function);
+        checkBus(secondaryBus);
+    }
+}
+
+
+// Brute-force scan
+void checkAllBuses (){
+    uint16_t bus;
+    uint8_t device;
+
+    for(bus = 0; bus < 256; bus++){
+        for(device = 0; device < 32; device++){
+            checkDevice(bus,device);
+        }
+    }
+}
+
+// Recursive scan
+void checkBus (uint8_t bus){
+    uint8_t device;
+
+    for(device = 0; device < 32; device ++){
+        checkDevice(bus,device);
+    }
+}
+
+void checkAllBuses(){
+    uint8_t function; 
+    uint8_t bus;
+
+    headerType = getHeaderType(0,0,0);
+    if ( (headerType & 0x80) == 0 ){
+        /* Single PCI host controller */
+        checkBus(0);
+    } else{
+        /* Multiple PCI host controllers */
+        for (function = 0; function < 8; function++){
+            if( CheckVendor(0,0) != 0xFFFF) {
+                break;
+            }
+            bus = function;
+            checkBus(bus);
+        }
+    }
+
+}

src/kernel/pci.h

@@ -0,0 +1,58 @@
+#pragma once
+#include <stdint.h>
+#include "io.h"
+// Configuration Space Access Mechanism #1
+#define CONFIG_ADDRESS 0xCF8 // Configuration adress that is to be accessed
+#define CONFIG_DATA 0xCFC // Will do the actual configuration operation
+
+/*
+CONFIG_ADDRESS 
+
+32 bit register 
+
+bit 31      Enable bit      (Should CONFIG_DATA be translatedc to configuration cycles)      
+bit 30 - 24 Reserved    
+bit 23 - 16 Bus Number      (Choose a specific PCI BUS)
+bit 15 - 11 Device Number   (Selects specific device one the pci bus)
+bit 10 - 8  Function Number (Selects a specific function in a device)
+bit 7 -  0  Register Offset (Offset in the configuration space of 256 Bytes ) NOTE: lowest two bits will always be zero 
+
+*/
+
+
+/* 
+PCI Device structure
+
+Register    offset  bits 31-24  bits 23-16  bits 15-8   bits 7-0
+00          00      Device ID   <----       Vendor  ID  <-------
+01          04      Status      <----       Command     <-------
+02          08      Class code  Sub class   Prog IF     Revision ID
+03          0C      BIST        Header Type Ltncy Timer Cache line Size
+04          10      Base address #0 (BAR0) 
+05          14      Base address #1 (BAR1) 
+06          18      Base address #2 (BAR2) 
+07          1C      Base address #3 (BAR3)
+08          20      Base address #4 (BAR4)
+09          24      Base address #5 (BAR5)
+0A          28      Cardbus CIS Pointer
+0B          2C      Subsystem ID <------   Subsystem Vendor ID  <-------
+0C          30      Expansion ROM base address
+0D          34      Reserved     <-------   Capabilities Pointer <------
+0E          38      Reserved    <-------    <--------   <--------
+0F          3C      Max ltncy   Min Grant   Interrupt PIN   Interrupt Line
+
+*/
+
+
+/*
+The idea for now is to support the minimal things necessary to find ATA supported drives
+ */
+
+
+// Lets write some boiler plate configuration code
+
+uint16_t ConfigReadWord (uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
+
+uint16_t CheckVendor (uint8_t bus, uint8_t slot);
+
+void checkDevice (uint8_t bus, uint8_t device );

src/kernel/pmm.cpp

@@ -0,0 +1 @@
+#include "pmm.h"

src/kernel/pmm.h

@@ -0,0 +1,125 @@
+#pragma once
+#include <stdint.h>
+// Lets assume we have 2 gigabytes of memory 
+// NOTE: We should really detect how much memory we have
+#define KiloByte 1024 // bytes
+#define MegaByte 1048576 // bytes
+#define GigaByte 1073741824 // bytes
+#define MemorySize 2147483648 // bytes
+
+const uint32_t bitmapSize = MemorySize / 8;
+
+extern void *kernel_begin;
+extern void *kernel_end;
+struct __attribute__((packed))  PMSegment {
+    void* address;
+    uint32_t size; 
+    PMSegment* Next;
+};
+
+
+static PMSegment pmStart;
+static uint32_t AvailablePhysicalMemory;  
+static uint32_t AllocatedMemorySize;
+
+void initPhysicalMemoryManager(){
+    AvailablePhysicalMemory = MemorySize;
+    AllocatedMemorySize = 0;
+
+    // Map the kernel
+    PMSegment KernelSegment = PMSegment();
+    printf("end of kernel: 0x%x\n", &kernel_end);
+    printf("start of kernel: 0x%x\n", &kernel_begin);
+    printf("pointer to kernel: 0x%x\n", &KernelSegment);
+
+    pmStart = KernelSegment;
+    KernelSegment.address = kernel_begin;
+    KernelSegment.size = &kernel_end - &kernel_begin;
+    AllocatedMemorySize += KernelSegment.size;
+    KernelSegment.Next = 0;
+
+    // make sure We allocate space for ourselves 
+    /*PMSegment start =  PMSegment();
+    start.address = KernelSegment.address + KernelSegment.size ;
+    start.size = (MemorySize /  sizeof(PMSegment) ) +  sizeof (uint32_t) * 2;
+    */
+
+    //KernelSegment.Next = &start;
+    //AllocatedMemorySize += start.size;
+}
+
+void printMemorySegments() 
+{
+    printf("Memory Segments:\n");
+    printf( "Start Segment: [addr: 0x%x, size: 0x%x, Next: 0x%x]\n" ,pmStart.address, pmStart.size, pmStart.Next);
+    printf("----------------------------\n");
+}
+
+
+void pmem_free (void* address){
+    
+    PMSegment* before = 0;
+    PMSegment* current = &pmStart;
+
+    printf("Address of pmStart : 0x%x\n", pmStart);
+    printf("Looking for segment with address: 0x%x \n", address );
+    printf("Address of pmStart(a.k.a current) : 0x%x \n", current);
+    while( current ) 
+    {
+        //printf("address of current segment 0x%x\n", current->address );
+        if ( current->address == address ) {
+            // this is the address we want to free
+            printf("Segment found!! Segment address: 0x%x \n", current->address);
+            if ( current->Next && before ){
+                before->Next = current->Next;
+            }else{
+                before->Next = 0;
+            }
+            // TODO: Clean memory [ Something like memset to zeroes]  
+            printf("Removing segment of size: 0x%x\n", current->size);
+            AllocatedMemorySize -= current->size;
+            break;
+        }
+
+        before = current;
+        current = current->Next;
+        
+    }
+
+}
+
+void* pmem_alloc ( uint32_t size ){
+    // Get the last segment
+    PMSegment* lastSegment = &pmStart;
+
+    while (lastSegment ) {
+        if( lastSegment->Next == 0){
+            break;
+        }
+        lastSegment = lastSegment->Next;
+    }   
+
+    printf("LastSegment is for address: 0x%x\n", lastSegment->address);
+
+
+    // So now we have the last segment available
+    PMSegment newSegment =  PMSegment();
+    newSegment.address = (PMSegment*)((uint32_t)lastSegment->address + lastSegment->size +1);
+
+    printf("NewSegment for Address: 0x%x\n", newSegment.address);
+
+    newSegment.size = size;
+
+    lastSegment->Next = &newSegment;
+
+    if ( AllocatedMemorySize + newSegment.size > AvailablePhysicalMemory){
+        // No segment available of this size
+        /// ERROR!!
+        return 0;
+    }
+    AllocatedMemorySize += newSegment.size;
+
+    return newSegment.address;
+    
+
+}

src/kernel/time.h

@@ -49,6 +49,8 @@ void read_rtc() {
       year = get_RTC_register(0x09);
       if(century_register != 0) {
             century = get_RTC_register(century_register);
+      } else {
+            century = 21;
       }
  
       do {
@@ -141,7 +143,7 @@ void WriteTOCMOS(unsigned char array[])
        asm("cli\n\t"       // Clear interrupts
          "mov al,index\n\t"    // move index address
          "out 0x70,al\n\t"     // copy address to CMOS register
-         /* some kind of real delay here is probably best 
+         // some kind of real delay here is probably best 
          "mov al,tvalue\n\t"   // move value to al
          "out 0x71,al\n\t"   // write 1 byte to CMOS
          "sti\n\\t"   );        // Enable interrupts

src/libc/include/string.c

@@ -0,0 +1,9 @@
+#include "string.h"
+
+size_t strlen(const char* str) {
+    size_t len = 0;
+    while(str[len]){
+        len++;
+    }
+    return len;
+}

src/libc/include/string.h

@@ -1,8 +1,3 @@
+#pragma once
 #include <stddef.h>
-size_t strlen(const char* str){
-    size_t len = 0;
-    while(str[len]){
-        len++;
-    }
-    return len;
-}
+size_t strlen(const char* str);