fixing more stuff and adding more stuff

src/boot/kernel_loader.asm

@@ -4,14 +4,9 @@ kernel_sector equ 1   ; Sector containing the kernel (adjust for your kernel's l
 kernel_segments equ 4  ; Number of sectors to load (adjust for your kernel size)
 kernel_load_address equ 0x1000 ; Memory address to load the kernel
 
-; ... (Function prototypes and int_13h implementation copied from previous response)
-; Function prototypes for readability
-; (These functions are not strictly necessary in NASM, but improve code organization)
-; Prototype for BIOS disk read interrupt (INT 13h)
 void int_13h(unsigned int ah, unsigned int al, unsigned int dx, unsigned int ch, unsigned int cl, unsigned int bx);
 
-; Function prototype for error handling or printing a message
-void error_handler(const char *message);
+void error_handler(const char *message)
 ; Main kernel loading code
 mov bx, kernel_load_address  ; Set load address
 

src/cpu/cpuid.asm

@@ -0,0 +1,18 @@
+[bits 32]
+
+global cpuid
+
+cpuid:
+  ; Input parameter in EAX register
+  mov eax, %edi
+
+  ; Call CPUID instruction (clobbers EAX, EBX, ECX, EDX)
+  cpuid
+
+  ; Return values in output registers
+  mov %esi, [esp + 4]   ; eax (output)
+  mov %edx, [esp + 8]   ; ebx (output)
+  mov %ecx, [esp + 12]  ; ecx (output)
+  mov %edi, [esp + 16]  ; edx (output)
+
+  ret

src/cpu/cpuid.c

@@ -0,0 +1,36 @@
+#include "cpuid.h"
+#include <stdint.h>
+
+void cpuid(uint32_t code, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx) {
+  asm volatile ("cpuid" : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx) : "a" (code));
+}
+
+void identify_cpu() {
+  uint32_t max_leaf;
+  uint32_t vendor_id[4];
+  uint32_t eax, ebx, ecx, edx;
+
+  // Get the maximum supported leaf value (CPUID function)
+  cpuid(0, &eax, &ebx, &ecx, &edx);
+  max_leaf = eax;
+
+  // Get the vendor ID string
+  cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
+  vendor_id[0] = eax;
+  vendor_id[1] = ebx;
+  vendor_id[2] = ecx;
+  vendor_id[3] = edx;
+
+  // Print the vendor ID string (assuming ASCII characters)
+  printf("Vendor ID: %.4s%.4s\n", (char *)&vendor_id[0], (char *)&vendor_id[1]);
+
+  // Identify basic features based on CPUID information (optional, needs further logic)
+  // ... (code to check specific CPU features using max_leaf and additional CPUID calls) ...
+
+  printf("Maximum leaf value: %u\n", max_leaf);
+}
+
+int main() {
+  identify_cpu();
+  return 0;
+}

src/cpu/cpuid.h

@@ -0,0 +1,7 @@
+#ifndef CPUID_H
+#define CPUID_H
+
+// Function prototypes for CPUID instruction
+void cpuid(uint32_t code, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx);
+
+#endif

src/drivers/io/io.c

@@ -15,8 +15,15 @@
     LPT3: 0x3BC
 */
 
+typedef enum {
+    IO_SUCCESS = 0,
+    IO_ERROR_PORT_NOT_READY,
+    IO_ERROR_PORT_UNAVAILABLE,
+    // Add more error codes as needed
+} IOErrorCode;
+
 // Function to initialize the ports before reading or writing
-void io_init()
+void io_init(uint16_t port)
 {
     // Initialize COM1 port (0x3F8) - You can add more port initializations here if needed
 

src/drivers/io/io.h

@@ -4,7 +4,7 @@
 #include <stdint.h>
 
 // Function to initialize the COM and LPT ports
-void io_init();
+void io_init(uint16_t port);
 
 // Function to read from the COM port
 char io_read_com();

src/drivers/keyboard/keyboard.c

@@ -22,14 +22,20 @@ static size_t keyboard_buffer_tail = 0;
 void set_interrupt_vector(uint8_t vector, void (*handler)());
 void enable_interrupt(uint8_t vector);
 
+bool keyboard_buffer_full()
+{
+    return (keyboard_buffer_head + 1) % KEYBOARD_BUFFER_SIZE == keyboard_buffer_tail;
+}
 void KeyboardInterruptHandler()
 {
-	uint8_t scancode = inb(KEYBOARD_DATA_PORT);
+	if (!keyboard_buffer_full())
+	{uint8_t scancode = inb(KEYBOARD_DATA_PORT);
 	uint8_t keycode = translate_scancode_to_keycode(scancode);
 
 	// Add scancode to buffer
 	keyboard_buffer[keyboard_buffer_head] = scancode;
 	keyboard_buffer_head = (keyboard_buffer_head + 1) % KEYBOARD_BUFFER_SIZE;
+	}
 }
 
 // Function to translate the combined extended scancode (first byte + second byte)
@@ -134,7 +140,30 @@ uint8_t translate_scancode_to_keycode(uint8_t scancode)
 		[0x51] = KEYCODE_PAGE_DOWN,
 		[0x52] = KEYCODE_INSERT,
 		[0x53] = KEYCODE_DELETE,
-
+		[0x54] = KEYCODE_HOME,
+		[0x55] = KEYCODE_UP,
+		[0x56] = KEYCODE_PAGE_UP,
+		[0x57] = KEYCODE_LEFT_CTRL_BREAK,  // Handle Break key (adjust if needed)
+		[0x58] = KEYCODE_RIGHT_SHIFT,
+		[0x59] = KEYCODE_NUM_LOCK,
+		[0x5A] = KEYCODE_SCROLL_LOCK,
+		[0x5B] = KEYCODE_F7,
+		[0x5C] = KEYCODE_F8,
+		[0x5D] = KEYCODE_F9,
+		[0x5E] = KEYCODE_F10,
+		[0x5F] = KEYCODE_PAUSE,  // Handle Pause key (adjust if needed)
+		[0x60] = KEYCODE_INSERT,
+		[0x61] = KEYCODE_DELETE,
+		[0x62] = KEYCODE_RIGHT,
+		[0x63] = KEYCODE_END,
+		[0x64] = KEYCODE_DOWN,
+		[0x65] = KEYCODE_PAGE_DOWN,
+		[0x66] = KEYCODE_F11,
+		[0x67] = KEYCODE_F12,
+		[0x68] = KEYCODE_UNKNOWN,  // (unused)
+		[0x69] = KEYCODE_LED_NUM_LOCK,  // Num Lock LED status
+		[0x6A] = KEYCODE_LED_CAPS_LOCK, // Caps Lock LED status
+		[0x6B] = KEYCODE_LED_SCROLL_LOCK
 		// ... (complete the rest based on the scancode table)
 		[0xE0] = 0, // Handle extended scancodes (e.g., Print Screen) separately
 	};

src/drivers/keyboard/keyboard.h

@@ -8,6 +8,7 @@ void KeyboardInterruptHandler();
 
 void keyboard_init();
 bool keyboard_buffer_empty();
+bool keyboard_buffer_full();
 uint8_t keyboard_read_scancode();
 void set_interrupt_vector(uint8_t vector, void (*handler)());
 void enable_interrupt(uint8_t vector);

src/drivers/network/ne2000.c

@@ -1,3 +1,4 @@
+#include "ne2000.h"
 #include <stdint.h>
 
 // NE2000 registers
@@ -12,15 +13,15 @@
 // ... more commands ...
 
 // Write a value to a NE2000 register
-void ne2000_write_reg(uint16_t base_addr, uint8_t reg, uint8_t value) {
-	volatile uint8_t *ne2000_reg = (volatile uint8_t *)(base_addr + reg);
-    *ne2000_reg = value;
+void ne2000_write_reg(uint16_t base_addr, uint8_t reg, uint8_t value)
+{
+	outb(base_addr + reg, value);
 }
 
 // Read a value from a NE2000 register
-uint8_t ne2000_read_reg(uint16_t base_addr, uint8_t reg) {
-	volatile uint8_t *ne2000_reg = (volatile uint8_t *)(base_addr + reg);
-	return *ne2000_reg;
+uint8_t ne2000_read_reg(uint16_t base_addr, uint8_t reg)
+{
+	return inb(base_addr + reg);
 }
 
 // Initialize the NE2000 card

src/drivers/network/ne2000.h

@@ -3,6 +3,9 @@
 
 #include <stdint.h>
 
+uint8_t inb(uint16_t port);
+void outb(uint16_t port, uint8_t value);
+
 // NE2000 registers
 #define NE2000_COMMAND 0x00
 #define NE2000_PSTART 0x01

src/filesystem/fat16/fat16.c

@@ -1,3 +1,32 @@
-/*
-fat16 goes here
-*/
+#include "fat16.h"
+#include <stdint.h>
+#include "fat16_io.h"
+
+// Implementation of read_sector and write_sector functions (replace with actual disk I/O)
+int read_sector(uint32_t sector_number, void *buffer)
+{
+	// ... (Code to read a sector from disk) ...
+}
+
+int write_sector(uint32_t sector_number, void *buffer)
+{
+	return read_sector_from_disk(sector_number, buffer);
+}
+
+// Function to parse the boot sector (replace with actual parsing logic)
+int parse_boot_sector(const char *device_name)
+{
+	// ... (Read and parse boot sector information) ...
+	return 0; // Or error code
+}
+
+// Function to mount the FAT16 volume (replace with actual mounting logic)
+int mount_fat16(const char *device_name)
+{
+	if (parse_boot_sector(device_name) != 0)
+	{
+		return -1; // Error parsing boot sector
+	}
+	// ... (Additional mounting logic) ...
+	return 0;
+}

src/filesystem/fat16/fat16.h

@@ -1,3 +1,26 @@
-/*
-fat16 goes here
-*/
+#ifndef FAT16_H
+#define FAT16_H
+
+#include <stdint.h>
+// Define constants for sector size, cluster size, etc. (replace with actual values)
+#define SECTOR_SIZE 512
+#define BYTES_PER_CLUSTER 4096 // Example: 8 sectors per cluster
+
+// Define structures for FAT entry, directory entry, etc.
+typedef struct
+{
+	// ... (FAT entry fields) ...
+} fat_entry_t;
+
+typedef struct
+{
+	// ... (Directory entry fields) ...
+} directory_entry_t;
+
+// Function prototypes for FAT operations
+int read_sector(uint32_t sector_number, void *buffer);
+int write_sector(uint32_t sector_number, void *buffer);
+int mount_fat16(const char *device_name); // Mount the FAT16 volume
+// ... (other function prototypes) ...
+
+#endif

src/filesystem/fat16/fat16_io.c

@@ -0,0 +1,50 @@
+#include "fat16_io.h"
+#include <stdint.h>
+// I/O port addresses for IDE controller (replace with actual values if needed)
+#define PRIMARY_DATA_REGISTER 0x1F0
+#define PRIMARY_ERROR_REGISTER 0x1F1
+#define PRIMARY_COMMAND_REGISTER 0x1F2
+#define PRIMARY_SELECT_REGISTER 0x1F6
+
+// Define bit masks for IDE commands
+#define ATA_CMD_READ_SECTORS_WITHOUT_RETRIES 0x20
+#define ATA_CMD_READ_SECTORS_WITH_RETRIES 0xC4
+
+// Function to read a sector from disk
+int read_sector(uint32_t sector_number, void *buffer)
+{
+	// 1. Prepare for disk access
+	outb(PRIMARY_SELECT_REGISTER, 0x00); // Select primary IDE channel
+
+	// 2. Wait for controller to become ready
+	while ((inb(PRIMARY_STATUS_REGISTER) & 0x02) == 0)
+	{
+	} // Wait for BUSY bit to clear
+
+	// 3. Send read command with parameters
+	outb(PRIMARY_COMMAND_REGISTER, ATA_CMD_READ_SECTORS_WITHOUT_RETRIES);  // Replace with retries if needed
+	outb(PRIMARY_ERROR_REGISTER, 0);									   // Features (usually set to 0)
+	outb(PRIMARY_SELECT_REGISTER, (sector_number & 0x0FF) | 0x80);		   // LBA low byte with LBA bit set
+	outb(PRIMARY_COMMAND_REGISTER, ((sector_number >> 8) & 0xFF));		   // LBA mid byte
+	outb(PRIMARY_COMMAND_REGISTER, ((sector_number >> 16) & 0x0F) | 0xE0); // LBA high byte with select bit
+	outb(PRIMARY_COMMAND_REGISTER, 1);									   // Number of sectors to read (1 in this case)
+
+	// 4. Wait for data transfer to complete (replace with timeout if needed)
+	while ((inb(PRIMARY_STATUS_REGISTER) & 0x08) == 0)
+	{
+	} // Wait for DRQ bit to set
+
+	// 5. Read data from the data register
+	for (int i = 0; i < 512; ++i)
+	{
+		((uint8_t *)buffer)[i] = inb(PRIMARY_DATA_REGISTER);
+	}
+
+	// 6. Check for errors (optional, implement error handling)
+	if (inb(PRIMARY_STATUS_REGISTER) & 0x01)
+	{
+		return -1; // Error occurred
+	}
+
+	return 0; // Success
+}

src/filesystem/fat16/fat16_io.h

@@ -0,0 +1,19 @@
+#ifndef FAT16_IO_H
+#define FAT16_IO_H
+
+#include <stdint.h>
+
+// I/O port addresses for IDE controller (replace with actual values if needed)
+#define PRIMARY_DATA_REGISTER 0x1F0
+#define PRIMARY_ERROR_REGISTER 0x1F1
+#define PRIMARY_COMMAND_REGISTER 0x1F2
+#define PRIMARY_SELECT_REGISTER 0x1F6
+
+// Define bit masks for IDE commands
+#define ATA_CMD_READ_SECTORS_WITHOUT_RETRIES 0x20
+#define ATA_CMD_READ_SECTORS_WITH_RETRIES 0xC4
+
+// Function prototype for reading a sector from disk
+int read_sector(uint32_t sector_number, void *buffer);
+
+#endif // FAT16_IO_H

src/kernel/arch/x86/idt.h

@@ -3,6 +3,12 @@
 
 #include "include/types.h"
 
+#define IDT_ENTRY_SIZE 16
+
+#if IDT_ENTRY_SIZE != 16
+#error "idt_entry structure size mismatch!"
+#endif
+
 // IDT entry structure
 struct idt_entry
 {
@@ -18,4 +24,9 @@ extern struct idt_entry idt[256];
 // Initialize the IDT
 void InitializeIDT();
 
+extern void KeyboardInterruptHandler();
+extern void TimerInterruptHandler();
+
+extern void LoadIDT(struct idt_entry *entry);
+
 #endif /* IDT_H */

src/kernel/arch/x86/isr/exceptions.c

@@ -4,37 +4,117 @@
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
+
+#define PAGE_SIZE 4096
+typedef struct memory_region_t
+{
+	void *start_address;
+	size_t size;
+} memory_region_t;
+
+// Array of allocated memory regions (example)
+memory_region_t *allocated_regions;
+size_t num_allocated_regions;
+
+jmp_buf page_fault_buffer;
 
 void DivideByZero()
 {
 	// Add logic to handle Divide By Zero Exception
-    printf("Divide By Zero Exception\n");
+	printf("Divide By Zero Exception\n");
 
-    // Additional Exception Handling Logic:
-    // Example: Perform specific actions for Divide By Zero scenario
-    // - Log the exception to a file
-    FILE *logFile = fopen("error.log", "a");
-    if (logFile != NULL) {
-        fprintf(logFile, "Divide By Zero Exception occurred\n");
-        fclose(logFile);
-    }
+	// Additional Exception Handling Logic:
+	// Example: Perform specific actions for Divide By Zero scenario
+	// - Log the exception to a file
+	FILE *logFile = fopen("error.log", "a");
+	if (logFile != NULL)
+	{
+		fprintf(logFile, "Divide By Zero Exception occurred\n");
+		fclose(logFile);
+	}
 
-    // - Gracefully terminate the kernel
-    printf("Exiting kernel due to Divide By Zero Exception\n");
+	// - Gracefully terminate the kernel
+	printf("Exiting kernel due to Divide By Zero Exception\n");
 	exit(EXIT_FAILURE);
 }
 
 void DoubleFault()
 {
-	// printf("Double Fault Exception");
+	printf("Double Fault Exception\n");
+	// Handle double fault exception (typically unrecoverable)
+	exit(EXIT_FAILURE);
 }
 
-void PageFault()
+// Function to check if address is within allocated memory (example)
+int IsAddressInRange(uint16_t address)
 {
-	// printf("Page Fault Exception");
+	for (size_t i = 0; i < num_allocated_regions; ++i)
+	{
+		if ((address >= allocated_regions[i].start_address) &&
+			(address < (allocated_regions[i].start_address + allocated_regions[i].size)))
+		{
+			return 1;
+		}
+	}
+	return 0;
+}
+
+// Placeholder for loading page from disk (replace with actual implementation)
+void LoadPageFromDisk(uint16_t fault_address, void *page_buffer)
+{
+	// Implement logic to read page data from disk based on fault_address
+	// and store it in the provided page_buffer
+	printf("** Placeholder: Load page from disk (implementation needed) **\n");
+}
+
+// Placeholder for modifying paging tables (replace with actual implementation)
+void NotifyCPUAboutPage(uint16_t fault_address)
+{
+	// Implement logic to modify paging tables based on fault_address
+	// to point to the loaded page data
+	printf("** Placeholder: Modify paging tables (implementation needed) **\n");
+}
+
+void PageFault(uint16_t fault_address)
+{
+	// 1. Identify the cause of the page fault
+	if (IsAddressInRange(fault_address))
+	{
+		// Address is within allocated memory, potentially a missing page
+		printf("Page fault for address 0x%x (potentially missing page)\n", fault_address);
+
+		// 2. Allocate memory for the page data (assuming OS doesn't handle this)
+		void *page_buffer = malloc(PAGE_SIZE); // Replace with actual page size
+		if (page_buffer == NULL)
+		{
+			printf("Failed to allocate memory for page data\n");
+			exit(EXIT_FAILURE);
+		}
+
+		// 3. Load the missing page from disk
+		LoadPageFromDisk(fault_address, page_buffer);
+
+		// 4. Inform the CPU that the page is now available
+		NotifyCPUAboutPage(fault_address);
+
+		// 5. Free the temporary page buffer (if applicable)
+		free(page_buffer);
+
+		// 6. Resume execution with longjmp
+		longjmp(page_fault_buffer, 1);
+	}
+	else
+	{
+		// Handle invalid memory access
+		printf("Invalid memory access at 0x%x\n", fault_address);
+		exit(EXIT_FAILURE); // Or perform alternative error handling
+	}
 }
 
 void GeneralProtectionFault()
 {
-	// printf("General Protection Fault Exception");
+	printf("General Protection Fault Exception\n");
+	// Handle general protection fault exception (access violation)
+	exit(EXIT_FAILURE);
 }

src/kernel/malloc/malloc.c

@@ -33,7 +33,6 @@ void *malloc(size_t size)
 	}
 
 	// Align the size to the word size for efficiency
-	size += sizeof(size_t) - 1;
 	size &= ~(sizeof(size_t) - 1);
 
 	// Search for a free block of sufficient size