Update ata.h

Updated header to match ata.c

kernel/display.c

@@ -1,80 +1,36 @@
-#include <string.h>
 #include "display.h"
-#include "io.h"
+#include "io.h" // Include your I/O header for port access
 #include "vga.h"
 
 // Initialize the display
 void init_display(void) {
-    // Initialize the VGA driver. This typically sets up the 80x25 text mode,
-    // clears the screen, and sets the cursor.
-    vga_init();
+    // Initialize VGA settings, if necessary
+    // This could involve setting up the VGA mode, etc.
+    set_display_mode(0x13); // Example: Set to 320x200 256-color mode
 }
 
 // Enumerate connected displays
 void enumerate_displays(void) {
-    // This function is often a complex operation in a real driver.
-    // In this simplified kernel/VGA text mode environment, we use printf
-    // to output a message and rely on the fact that VGA is present.
+    // This is a simplified example. Actual enumeration may require
+    // reading from specific VGA registers or using BIOS interrupts.
     
-    // Clear the display before printing a message
-    vga_clear(vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK));
-    
-    // Output a simplified enumeration message
-    vga_printf("Display: Standard VGA Text Mode (80x25) Detected.\n");
-    
-    // In a real driver, you would use inb() and outb() with specific VGA ports
-    // to read information (e.g., from the CRTC registers 0x3D4/0x3D5)
-    // to check for display presence or configuration.
+    // For demonstration, we will just print a message
+    // In a real driver, you would check the VGA registers
+    // to determine connected displays.
+    clear_display();
+    // Here you would typically read from VGA registers to find connected displays
+    // For example, using inb() to read from VGA ports
 }
 
 // Set the display mode
-// NOTE: Setting arbitrary VGA modes (like 0x13 for 320x200) is very complex
-// and requires writing hundreds of register values, often done via BIOS in
-// real mode. Since we are in protected mode and have a simple text driver,
-// this function is kept simple or treated as a placeholder for full mode changes.
 void set_display_mode(uint8_t mode) {
-    // Check if the requested mode is a known mode (e.g., VGA Text Mode 3)
-    // For this example, we simply acknowledge the call.
-    // A true mode set would involve complex register sequencing.
-    
-    // The provided vga.c is a Text Mode driver, so a graphical mode set
-    // like 0x13 (320x200 256-color) would break the existing vga_printf functionality.
-    
-    // A simplified text-mode-specific response:
-    if (mode == 0x03) { // Mode 3 is standard 80x25 text mode
-        vga_printf("Display mode set to 80x25 Text Mode (Mode 0x03).\n");
-        vga_init(); // Re-initialize the text mode
-    } else {
-        // Simple I/O example based on the original structure (Caution: Incomplete for full mode set)
-        outb(VGA_PORT, mode); // Example function to write to a port
-        vga_printf("Attempting to set display mode to 0x%x. (Warning: May break current display)\n", mode);
-    }
+    // Set the VGA mode by writing to the appropriate registers
+    outb(VGA_PORT, mode); // Example function to write to a port
 }
 
 // Clear the display
 void clear_display(void) {
-    // Use the VGA driver's clear function, typically clearing to black on light grey
-    // or black on black. We'll use the black on light grey from vga_init for consistency.
-    vga_clear(vga_entry_color(VGA_COLOR_BLACK, VGA_COLOR_LIGHT_GREY));
-    // Reset cursor to 0, 0
-    vga_set_cursor_position(0, 0);
-}
-
-// Helper function to write a string
-void display_write_string(const char* str) {
-    // Use the VGA driver's string writing function
-    vga_write_string(str, strlen(str));
-}
-
-// Helper function to print a formatted string
-void display_printf(const char* format, ...) {
-    // Use the VGA driver's printf function
-    va_list args;
-    va_start(args, format);
-    
-    // The vga_printf function already handles the va_list internally,
-    // so we can just call it directly.
-    vga_printf(format, args);
-    
-    va_end(args);
+    // Clear the display by filling it with a color
+    // This is a placeholder for actual clearing logic
+    // You would typically write to video memory here
 }

kernel/display.h

@@ -2,21 +2,13 @@
 #define DISPLAY_H
 
 #include <stdint.h>
-#include "vga.h" // Include VGA functions
 
-#define VGA_PORT 0x3C0  // Base port for VGA (Often used for general control, though 0x3D4/0x3D5 are used for cursor)
+#define VGA_PORT 0x3C0  // Base port for VGA
 
 // Function prototypes
 void init_display(void);
 void enumerate_displays(void);
-void set_display_mode(uint8_t mode); // In this context, modes are typically BIOS or VESA modes, which are complex.
-                                      // We'll treat this as a placeholder/simple mode call.
+void set_display_mode(uint8_t mode);
 void clear_display(void);
 
-// New function to write a string using the VGA driver
-void display_write_string(const char* str);
-
-// New function to print a formatted string using the VGA driver
-void display_printf(const char* format, ...);
-
 #endif // DISPLAY_H

kernel/fat16.c

@@ -1,107 +0,0 @@
-#include "fat16.h"
-#include "ata.h"   // Use ata_read_sector and ata_write_sector
-#include "print.h" // For debugging
-#include <string.h> // For string manipulation
-
-// Global variables
-static fat16_boot_sector_t boot_sector;
-static uint32_t root_dir_sector = FAT16_ROOT_DIR_SECTOR;
-
-// Read a sector from the disk using ATA
-bool read_sector(uint32_t lba, uint8_t* buffer) {
-    return ata_read_sector(lba, buffer);
-}
-
-// Write a sector to the disk using ATA
-bool write_sector(uint32_t lba, const uint8_t* buffer) {
-    return ata_write_sector(lba, buffer);
-}
-
-// Parse the boot sector to retrieve basic file system info
-bool parse_fat16_boot_sector(void) {
-    uint8_t sector_buffer[FAT16_SECTOR_SIZE];
-
-    // Read the boot sector
-    if (!read_sector(FAT16_BOOT_SECTOR, sector_buffer)) {
-        print_string("[FAT16] Failed to read boot sector\n");
-        return false;
-    }
-
-    // Cast to boot sector structure
-    memcpy(&boot_sector, sector_buffer, sizeof(fat16_boot_sector_t));
-
-    // Check for FAT16 signature
-    if (boot_sector.oem_name[0] != 'F' || boot_sector.oem_name[1] != 'A' || boot_sector.oem_name[2] != 'T') {
-        print_string("[FAT16] Invalid FAT16 boot sector signature\n");
-        return false;
-    }
-
-    print_string("[FAT16] FAT16 boot sector parsed successfully\n");
-    return true;
-}
-
-// Parse the root directory
-bool parse_fat16_root_dir(void) {
-    uint8_t sector_buffer[FAT16_SECTOR_SIZE];
-
-    for (int i = 0; i < (boot_sector.max_root_entries / (FAT16_SECTOR_SIZE / sizeof(fat16_dir_entry_t))); i++) {
-        // Read root directory sector
-        if (!read_sector(root_dir_sector + i, sector_buffer)) {
-            print_string("[FAT16] Failed to read root directory sector\n");
-            return false;
-        }
-
-        // Parse the root directory entries
-        for (int j = 0; j < (FAT16_SECTOR_SIZE / sizeof(fat16_dir_entry_t)); j++) {
-            fat16_dir_entry_t* entry = (fat16_dir_entry_t*)&sector_buffer[j * sizeof(fat16_dir_entry_t)];
-            if (entry->name[0] == 0x00) {
-                // End of directory entries
-                return true;
-            }
-            if (entry->name[0] != 0xE5) {
-                // Print file name (8.3 format)
-                char filename[12];
-                strncpy(filename, (char*)entry->name, 8);
-                filename[8] = '.';
-                strncpy(&filename[9], (char*)entry->ext, 3);
-                filename[11] = '\0';
-                print_string(filename);
-                print_string("\n");
-            }
-        }
-    }
-    return true;
-}
-
-// Read a specific directory entry from the FAT16 root directory
-bool read_fat16_entry(uint16_t entry_index, fat16_dir_entry_t* entry) {
-    uint8_t sector_buffer[FAT16_SECTOR_SIZE];
-    uint32_t sector_num = FAT16_ROOT_DIR_SECTOR + (entry_index / (FAT16_SECTOR_SIZE / sizeof(fat16_dir_entry_t)));
-    uint16_t entry_offset = entry_index % (FAT16_SECTOR_SIZE / sizeof(fat16_dir_entry_t));
-
-    // Read the sector
-    if (!read_sector(sector_num, sector_buffer)) {
-        print_string("[FAT16] Failed to read root directory sector\n");
-        return false;
-    }
-
-    // Get the entry
-    memcpy(entry, &sector_buffer[entry_offset * sizeof(fat16_dir_entry_t)], sizeof(fat16_dir_entry_t));
-    return true;
-}
-
-// Mount the FAT16 filesystem
-bool mount_fat16(void) {
-    // Parse the boot sector
-    if (!parse_fat16_boot_sector()) {
-        return false;
-    }
-
-    // Parse the root directory
-    if (!parse_fat16_root_dir()) {
-        return false;
-    }
-
-    print_string("[FAT16] Filesystem mounted successfully\n");
-    return true;
-}

kernel/fat16.h

@@ -1,60 +0,0 @@
-#ifndef FAT16_H
-#define FAT16_H
-
-#include <stdint.h>
-#include <stdbool.h>
-
-/* FAT16 Constants */
-#define FAT16_SECTOR_SIZE        512
-#define FAT16_CLUSTER_SIZE       1
-#define FAT16_MAX_FILENAME_LEN   11   // 8.3 format
-#define FAT16_ROOT_DIR_ENTRIES   224  // Fat16 root directory entries (typically 512 bytes per entry)
-
-#define FAT16_BOOT_SECTOR        0
-#define FAT16_FAT1_SECTOR        1
-#define FAT16_FAT2_SECTOR        2
-#define FAT16_ROOT_DIR_SECTOR    19  // First sector of root directory
-
-/* Boot Sector */
-typedef struct {
-    uint8_t jmp[3];               // Jump instruction to code
-    uint8_t oem_name[8];          // OEM Name
-    uint16_t bytes_per_sector;    // Bytes per sector (512)
-    uint8_t sectors_per_cluster;  // Sectors per cluster
-    uint16_t reserved_sectors;    // Reserved sectors
-    uint8_t num_fats;             // Number of FAT tables
-    uint16_t max_root_entries;    // Max number of root directory entries
-    uint16_t total_sectors_16;    // Total sectors in FAT16
-    uint8_t media_type;           // Media type (0xF8 = fixed drive)
-    uint16_t sectors_per_fat;    // Sectors per FAT table
-    uint16_t sectors_per_track;  // Sectors per track (for CHS addressing)
-    uint16_t num_heads;          // Number of heads (for CHS addressing)
-    uint32_t hidden_sectors;     // Hidden sectors (before the partition)
-    uint32_t total_sectors_32;   // Total sectors in FAT16 (extended)
-} __attribute__((packed)) fat16_boot_sector_t;
-
-/* FAT16 Directory Entry */
-typedef struct {
-    uint8_t name[8];   // File name (8 chars)
-    uint8_t ext[3];    // File extension (3 chars)
-    uint8_t attributes; // File attributes (e.g., directory, read-only)
-    uint8_t reserved;   // Reserved
-    uint8_t creation_time[2]; // Creation time
-    uint8_t creation_date[2]; // Creation date
-    uint8_t last_access_date[2]; // Last access date
-    uint8_t first_cluster_high[2]; // High part of first cluster number
-    uint8_t last_mod_time[2];  // Last modification time
-    uint8_t last_mod_date[2];  // Last modification date
-    uint8_t first_cluster_low[2];  // Low part of first cluster number
-    uint32_t file_size;         // File size in bytes
-} __attribute__((packed)) fat16_dir_entry_t;
-
-/* Function Prototypes */
-bool mount_fat16(void);
-bool read_sector(uint32_t lba, uint8_t* buffer);
-bool write_sector(uint32_t lba, const uint8_t* buffer);
-bool parse_fat16_boot_sector(void);
-bool parse_fat16_root_dir(void);
-bool read_fat16_entry(uint16_t entry_index, fat16_dir_entry_t* entry);
-
-#endif // FAT16_H

kernel/gui.c

@@ -1,66 +0,0 @@
-#include "gui.h"
-#include "vga.h"  // VGA functions for drawing and clearing screen
-#include "framebuffer.h"  // For pixel manipulation if needed
-
-// Initialize the GUI (could set up any global state or variables here)
-void gui_init(void) {
-    // Clear the screen with black or any color
-    gui_clear(vga_entry_color(VGA_COLOR_BLACK, VGA_COLOR_WHITE));
-}
-
-// Draw a window (simple rectangle with a title)
-void gui_draw_window(gui_window_t* window) {
-    // Draw the window's border
-    for (uint32_t y = 0; y < window->height; ++y) {
-        for (uint32_t x = 0; x < window->width; ++x) {
-            // Check if we are at the border
-            if (x == 0 || y == 0 || x == window->width - 1 || y == window->height - 1) {
-                vga_put_entry_at('#', vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK), window->x + x, window->y + y);
-            } else {
-                // Fill the inside of the window
-                vga_put_entry_at(' ', vga_entry_color(VGA_COLOR_BLACK, VGA_COLOR_BLACK), window->x + x, window->y + y);
-            }
-        }
-    }
-
-    // Draw the title at the top
-    if (window->title) {
-        size_t i = 0;
-        while (window->title[i] != '\0' && i < window->width - 2) {
-            vga_put_entry_at(window->title[i], vga_entry_color(VGA_COLOR_WHITE, VGA_COLOR_BLACK), window->x + i + 1, window->y);
-            i++;
-        }
-    }
-}
-
-// Draw a button (a simple rectangle with text in the middle)
-void gui_draw_button(gui_button_t* button) {
-    for (uint32_t y = 0; y < button->height; ++y) {
-        for (uint32_t x = 0; x < button->width; ++x) {
-            // Check if we are at the border
-            if (x == 0 || y == 0 || x == button->width - 1 || y == button->height - 1) {
-                vga_put_entry_at('#', vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK), button->x + x, button->y + y);
-            } else {
-                // Fill the inside of the button
-                vga_put_entry_at(' ', vga_entry_color(VGA_COLOR_BLACK, VGA_COLOR_BLACK), button->x + x, button->y + y);
-            }
-        }
-    }
-
-    // Draw the label in the center of the button
-    size_t label_len = 0;
-    while (button->label[label_len] != '\0') {
-        label_len++;
-    }
-
-    size_t start_x = button->x + (button->width - label_len) / 2;
-    size_t start_y = button->y + (button->height - 1) / 2;
-    for (size_t i = 0; i < label_len; ++i) {
-        vga_put_entry_at(button->label[i], vga_entry_color(VGA_COLOR_WHITE, VGA_COLOR_BLACK), start_x + i, start_y);
-    }
-}
-
-// Clear the screen with a color
-void gui_clear(uint32_t color) {
-    vga_clear(color);  // Just clear the VGA screen with a solid color
-}

kernel/gui.h

@@ -1,34 +0,0 @@
-#ifndef GUI_H
-#define GUI_H
-
-#include <stdint.h>
-#include <stddef.h>
-
-#define GUI_WINDOW_WIDTH   80
-#define GUI_WINDOW_HEIGHT  25
-#define GUI_BUTTON_WIDTH   10
-#define GUI_BUTTON_HEIGHT  3
-
-// Window structure
-typedef struct {
-    uint32_t x, y;
-    uint32_t width, height;
-    uint32_t color;  // Background color
-    const char* title;
-} gui_window_t;
-
-// Button structure
-typedef struct {
-    uint32_t x, y;
-    uint32_t width, height;
-    uint32_t color;  // Background color
-    const char* label;
-} gui_button_t;
-
-// Function prototypes for GUI elements
-void gui_init(void);
-void gui_draw_window(gui_window_t* window);
-void gui_draw_button(gui_button_t* button);
-void gui_clear(uint32_t color);
-
-#endif // GUI_H

kernel/hid.c

@@ -1,65 +0,0 @@
-#include "hid.h"
-#include "usb.h"
-#include "mouse.h"
-#include "keyboard.h"
-#include "print.h"
-#include <stdint.h>
-#include <stdbool.h>
-
-// Global variables
-static bool hid_initialized = false;
-
-void hid_init(void) {
-    if (hid_initialized) return;
-    hid_initialized = true;
-
-    // Initialize keyboard and mouse HID handling
-    keyboard_init();
-    // Assume USB mouse has been initialized and is connected.
-    usb_hid_init(); // Initializes USB HID for both keyboard and mouse
-}
-
-void hid_process_report(uint8_t* report, uint8_t length) {
-    // Process the HID report based on its type
-    if (length == 8) {  // Assuming a standard 8-byte report for HID keyboard
-        keyboard_hid_report_t* k_report = (keyboard_hid_report_t*) report;
-        hid_process_keyboard_report(k_report);
-    } else if (length == 3) {  // Assuming a standard 3-byte report for HID mouse
-        mouse_hid_report_t* m_report = (mouse_hid_report_t*) report;
-        hid_process_mouse_report(m_report);
-    }
-}
-
-// Handle HID keyboard report
-void hid_process_keyboard_report(const keyboard_hid_report_t* report) {
-    // Iterate over the keycodes and process key presses
-    for (int i = 0; i < 6; i++) {
-        uint8_t keycode = report->keycodes[i];
-        if (keycode != 0) {
-            char key = scancode_map[keycode];
-            if (key) {
-                keyboard_buffer_add(key);
-            }
-        }
-    }
-}
-
-// Handle HID mouse report
-void hid_process_mouse_report(const mouse_hid_report_t* report) {
-    // Process mouse movement and button clicks
-    mouse_data.x += report->x;
-    mouse_data.y += report->y;
-    mouse_data.left_button = (report->buttons & 0x01) != 0;
-    mouse_data.right_button = (report->buttons & 0x02) != 0;
-
-    print_hex((uint32_t)mouse_data.x, 1, 1);
-    print_hex((uint32_t)mouse_data.y, 1, 1);
-    print_hex((uint32_t)report->buttons, 1, 1);
-}
-
-// Parse the HID descriptor (for parsing USB HID device descriptors)
-bool hid_parse_descriptor(uint8_t* descriptor, uint32_t length) {
-    // HID descriptors are defined in the USB HID specification, we'll need to parse them here.
-    // For now, just return true assuming we have a valid descriptor.
-    return true;
-}

kernel/hid.h

@@ -1,46 +0,0 @@
-#ifndef HID_H
-#define HID_H
-
-#include <stdint.h>
-#include <stdbool.h>
-
-// HID Report types
-#define HID_REPORT_INPUT  0x01
-#define HID_REPORT_OUTPUT 0x02
-#define HID_REPORT_FEATURE 0x03
-
-// HID usage page constants (USB HID)
-#define HID_USAGE_PAGE_GENERIC 0x01
-#define HID_USAGE_KEYBOARD 0x06
-#define HID_USAGE_MOUSE 0x02
-
-// HID keyboard and mouse data
-typedef struct {
-    uint8_t modifier;    // Modifier keys (shift, ctrl, alt, etc.)
-    uint8_t reserved;    // Reserved byte
-    uint8_t keycodes[6]; // Keycodes for keys pressed
-} keyboard_hid_report_t;
-
-typedef struct {
-    uint8_t buttons;     // Mouse buttons (bitwise: 0x01 = left, 0x02 = right, 0x04 = middle)
-    int8_t x;            // X axis movement
-    int8_t y;            // Y axis movement
-    int8_t wheel;        // Mouse wheel
-} mouse_hid_report_t;
-
-// Initialize the HID subsystem
-void hid_init(void);
-
-// Process an incoming HID report
-void hid_process_report(uint8_t* report, uint8_t length);
-
-// Process HID keyboard report
-void hid_process_keyboard_report(const keyboard_hid_report_t* report);
-
-// Process HID mouse report
-void hid_process_mouse_report(const mouse_hid_report_t* report);
-
-// USB HID report descriptor parsing
-bool hid_parse_descriptor(uint8_t* descriptor, uint32_t length);
-
-#endif // HID_H

kernel/keyboard.c

@@ -2,91 +2,64 @@
 #include "io.h"
 #include "isr.h"
 #include "terminal.h"
-#include <stddef.h>
 
 #define KEYBOARD_DATA_PORT 0x60
 #define KEY_BUFFER_SIZE 256
 
-// Use volatile so the compiler knows these change inside interrupts
-static volatile char key_buffer[KEY_BUFFER_SIZE];
-static volatile uint8_t buffer_head = 0;
-static volatile uint8_t buffer_tail = 0;
-static volatile uint8_t buffer_count = 0;
+static char key_buffer[KEY_BUFFER_SIZE];
+static uint8_t buffer_head = 0;  // Write position (interrupt)
+static uint8_t buffer_tail = 0;  // Read position (get_char)
+static uint8_t buffer_count = 0;
+static uint8_t buffer_index = 0;
 
-// Exported map: Removed 'static' so hid.c can reference it if needed
-const char scancode_map[128] = {
-    0,  27, '1', '2', '3', '4', '5', '6', '7', '8',
-    '9', '0', '-', '=', '\b', '\t', 'q', 'w', 'e', 'r',
-    't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n', 0,
-    'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';',
-    '\'', '`', 0, '\\', 'z', 'x', 'c', 'v', 'b', 'n',
-    'm', ',', '.', '/', 0, '*', 0, ' ', 0
+// Basic US QWERTY keymap (scancode to ASCII)
+static const char scancode_map[128] = {
+    0,  27, '1', '2', '3', '4', '5', '6', '7', '8', // 0x00 - 0x09
+   '9', '0', '-', '=', '\b', '\t', 'q', 'w', 'e', 'r', // 0x0A - 0x13
+   't', 'y', 'z', 'u', 'i', 'o', 'p', '[', ']', '\n', // 0x14 - 0x1D
+    0, 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', // 0x1E - 0x27
+   ';', '\'', '`', 0, '\\', 'x', 'c', 'v', 'b', // 0x28 - 0x31
+   'n', 'm', ',', '.', '/', 0, '*', 0, ' ', 0,      // 0x32 - 0x3B
+    // rest can be filled as needed
 };
 
-/**
- * Shared function used by both PS/2 (callback) and USB (hid.c)
- * This fixes the "undefined reference to keyboard_buffer_add" error.
- */
-void keyboard_buffer_add(char c) {
+// Interrupt handler for IRQ1
+void keyboard_callback(void) {
+    uint8_t scancode = inb(KEYBOARD_DATA_PORT);
+
+    if (scancode & 0x80) return;  // Ignore key release
+
+    char c = scancode_map[scancode];
     if (!c) return;
 
     uint8_t next_head = (buffer_head + 1) % KEY_BUFFER_SIZE;
 
-    // If buffer is full, we must drop the key
-    if (next_head == buffer_tail) {
-        return; 
-    }
+    // Drop key if buffer full
+    if (next_head == buffer_tail) return;
 
     key_buffer[buffer_head] = c;
     buffer_head = next_head;
     buffer_count++;
 
-    // Echo to terminal
     terminal_putchar(c);
 }
 
-/**
- * Hardware Interrupt Handler for PS/2
- */
-void keyboard_callback(void) {
-    uint8_t scancode = inb(KEYBOARD_DATA_PORT);
-
-    // Ignore break codes (key release)
-    if (scancode & 0x80) return; 
-
-    char c = scancode_map[scancode];
-    keyboard_buffer_add(c);
+void keyboard_init() {
+    register_interrupt_handler(33, keyboard_callback); // IRQ1 = int 33 (0x21)
 }
 
-void keyboard_init(void) {
-    buffer_head = 0;
-    buffer_tail = 0;
-    buffer_count = 0;
-    // IRQ1 is usually mapped to IDT entry 33
-    register_interrupt_handler(33, keyboard_callback); 
-}
-
-/**
- * Blocking read with a safe HLT to prevent CPU 100% usage
- */
+// Blocking read (returns one char)
 char keyboard_get_char(void) {
-    char c;
-
-    while (1) {
-        __asm__ __volatile__("cli"); // Disable interrupts to check buffer_count safely
-        
-        if (buffer_count > 0) {
-            c = key_buffer[buffer_tail];
-            buffer_tail = (buffer_tail + 1) % KEY_BUFFER_SIZE;
-            buffer_count--;
-            __asm__ __volatile__("sti"); // Re-enable interrupts after reading
-            return c;
-        }
-
-        /* * IMPORTANT: 'sti' followed by 'hlt' is guaranteed by x86 
-         * to execute 'hlt' BEFORE the next interrupt can trigger.
-         * This prevents the race condition hang.
-         */
-        __asm__ __volatile__("sti; hlt"); 
+    while (buffer_count == 0) {
+        __asm__ __volatile__("hlt");  // Better than busy loop
     }
+
+    char c;
+    __asm__ __volatile__("cli");
+    c = key_buffer[buffer_tail];
+    buffer_tail = (buffer_tail + 1) % KEY_BUFFER_SIZE;
+    buffer_count--;
+    __asm__ __volatile__("sti");
+
+    return c;
 }

kernel/keyboard.h

@@ -1,12 +1,7 @@
 #ifndef KEYBOARD_H
 #define KEYBOARD_H
 
-#include <stdint.h>
-
 void keyboard_init(void);
-void keyboard_buffer_add(char c);
-char keyboard_get_char(void);  
-
-extern const char scancode_map[128]; 
+char keyboard_get_char(void);  // Blocking read from buffer
 
 #endif

kernel/mouse.c

@@ -5,7 +5,7 @@
 #include <stdbool.h>
 
 // Mouse buffer
-mouse_data_t mouse_data;
+static mouse_data_t mouse_data;
 
 // Read USB mouse data
 mouse_data_t usb_read_mouse(void) {

kernel/mouse.h

@@ -12,8 +12,6 @@ typedef struct {
     bool right_button;
 } mouse_data_t;
 
-extern mouse_data_t mouse_data;
-
 // Function declarations for USB 1.x HID mouse support
 bool usb_mouse_init(void);
 bool usb_mouse_detected(void);

kernel/vga.c

@@ -1,9 +1,9 @@
+#include "vga.h"
 #include <stddef.h>
 #include <stdbool.h>
 #include <string.h>
 #include <stdarg.h>
 #include "string_utils.h"
-#include "vga.h"
 
 void outb(uint16_t port, uint8_t value) {
     __asm__ volatile("outb %0, %1" : : "a"(value), "Nd"(port));
@@ -134,7 +134,7 @@ void vga_printf(const char* format, ...) {
     va_end(args);
     
     // Now you can use the buffer with vga_write_string
-    vga_write_string(buffer, strlen(buffer)); // Use my_strlen instead of strlen
+    vga_write_string(buffer, my_strlen(buffer)); // Use my_strlen instead of strlen
 }
 
 void vga_init(void) {

kernel/vga.h

@@ -35,7 +35,6 @@ typedef enum {
 // Function prototypes
 uint8_t vga_entry_color(vga_color fg, vga_color bg);
 uint16_t vga_entry(unsigned char uc, uint8_t color);
-void vga_init(void);
 
 void vga_put_entry_at(char c, uint8_t color, size_t x, size_t y);
 void vga_clear(uint8_t color);
@@ -51,4 +50,4 @@ void vga_set_cursor_blink_rate(uint8_t rate);
 
 void vga_printf(const char* format, ...);
 
-#endif
+#endif