Update ata.h

Updated header to match ata.c

kernel/ata.c

@@ -0,0 +1,119 @@
+#include "ata.h"
+#include "io.h"
+#include "print.h"
+
+#define ATA_TIMEOUT 100000
+
+static inline void ata_delay(void) {
+    /* 400ns delay by reading alternate status */
+    inb(ATA_PRIMARY_CTRL);
+    inb(ATA_PRIMARY_CTRL);
+    inb(ATA_PRIMARY_CTRL);
+    inb(ATA_PRIMARY_CTRL);
+}
+
+bool ata_wait_ready(void) {
+    for (int i = 0; i < ATA_TIMEOUT; i++) {
+        uint8_t status = inb(ATA_PRIMARY_IO + ATA_REG_STATUS);
+        /* Must NOT be busy AND must be ready */
+        if (!(status & ATA_SR_BSY) && (status & ATA_SR_DRDY))
+            return true;
+    }
+    return false;
+}
+
+static bool ata_wait(uint8_t mask) {
+    for (int i = 0; i < ATA_TIMEOUT; i++) {
+        uint8_t status = inb(ATA_PRIMARY_IO + ATA_REG_STATUS);
+        /* If ERR is set, stop waiting and return failure */
+        if (status & ATA_SR_ERR) return false;
+        
+        if (!(status & ATA_SR_BSY) && (status & mask))
+            return true;
+    }
+    return false;
+}
+
+bool ata_init(void) {
+    /* Select drive */
+    outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, ATA_MASTER);
+    ata_delay();
+
+    /* Check if drive exists */
+    uint8_t status = inb(ATA_PRIMARY_IO + ATA_REG_STATUS);
+    if (status == 0xFF || status == 0) return false;
+
+    outb(ATA_PRIMARY_IO + ATA_REG_COMMAND, ATA_CMD_IDENTIFY);
+    ata_delay();
+
+    if (!ata_wait(ATA_SR_DRQ))
+        return false;
+
+    uint16_t identify[256];
+    for (int i = 0; i < 256; i++)
+        identify[i] = inw(ATA_PRIMARY_IO);
+
+    print_string("[ATA] Primary master detected\n");
+    return true;
+}
+
+bool ata_read_sector(uint32_t lba, uint8_t* buffer) {
+    if (!buffer) return false;
+
+    /* 1. Wait for drive to be ready for command */
+    if (!ata_wait_ready()) return false;
+
+    /* 2. Setup Task File (LBA28) */
+    outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xE0 | ((lba >> 24) & 0x0F));
+    outb(ATA_PRIMARY_IO + ATA_REG_SECCOUNT0, 1);
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA0, (uint8_t)(lba));
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA1, (uint8_t)(lba >> 8));
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA2, (uint8_t)(lba >> 16));
+    
+    /* 3. Issue Read Command */
+    outb(ATA_PRIMARY_IO + ATA_REG_COMMAND, ATA_CMD_READ_PIO);
+
+    /* 4. Wait for Data Request (DRQ) */
+    if (!ata_wait(ATA_SR_DRQ))
+        return false;
+
+    /* 5. Transfer data */
+    for (int i = 0; i < 256; i++) {
+        uint16_t data = inw(ATA_PRIMARY_IO);
+        buffer[i * 2]     = data & 0xFF;
+        buffer[i * 2 + 1] = (data >> 8) & 0xFF;
+    }
+
+    ata_delay();
+    return true;
+}
+
+bool ata_write_sector(uint32_t lba, const uint8_t* buffer) {
+    if (!buffer) return false;
+
+    /* 1. Wait for drive to be ready for command */
+    if (!ata_wait_ready()) return false;
+
+    /* 2. Setup Task File */
+    outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xE0 | ((lba >> 24) & 0x0F));
+    outb(ATA_PRIMARY_IO + ATA_REG_SECCOUNT0, 1);
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA0, (uint8_t)(lba));
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA1, (uint8_t)(lba >> 8));
+    outb(ATA_PRIMARY_IO + ATA_REG_LBA2, (uint8_t)(lba >> 16));
+    
+    /* 3. Issue Write Command */
+    outb(ATA_PRIMARY_IO + ATA_REG_COMMAND, ATA_CMD_WRITE_PIO);
+
+    /* 4. Wait for drive to request data */
+    if (!ata_wait(ATA_SR_DRQ))
+        return false;
+
+    /* 5. Transfer data */
+    for (int i = 0; i < 256; i++) {
+        uint16_t word = buffer[i * 2] | (buffer[i * 2 + 1] << 8);
+        outw(ATA_PRIMARY_IO, word);
+    }
+
+    ata_delay();
+    return true;
+}

kernel/ata.h

@@ -0,0 +1,44 @@
+#ifndef ATA_H
+#define ATA_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/* ATA I/O ports */
+#define ATA_PRIMARY_IO     0x1F0
+#define ATA_PRIMARY_CTRL   0x3F6
+
+/* ATA registers */
+#define ATA_REG_DATA       0x00
+#define ATA_REG_ERROR      0x01
+#define ATA_REG_FEATURES   0x01
+#define ATA_REG_SECCOUNT0  0x02
+#define ATA_REG_LBA0       0x03
+#define ATA_REG_LBA1       0x04
+#define ATA_REG_LBA2       0x05
+#define ATA_REG_HDDEVSEL   0x06
+#define ATA_REG_COMMAND    0x07
+#define ATA_REG_STATUS     0x07
+
+/* ATA commands */
+#define ATA_CMD_READ_PIO   0x20
+#define ATA_CMD_WRITE_PIO  0x30
+#define ATA_CMD_IDENTIFY   0xEC
+
+/* Status flags */
+#define ATA_SR_BSY         0x80
+#define ATA_SR_DRDY        0x40
+#define ATA_SR_DRQ         0x08
+#define ATA_SR_ERR         0x01
+
+/* Drive select */
+#define ATA_MASTER         0xA0
+#define ATA_SLAVE          0xB0
+
+/* Public API */
+bool ata_init(void);
+bool ata_read_sector(uint32_t lba, uint8_t* buffer);
+bool ata_write_sector(uint32_t lba, const uint8_t* buffer);
+bool ata_wait_ready(void);
+
+#endif

kernel/display.c

@@ -1,36 +1,80 @@
+#include <string.h>
 #include "display.h"
-#include "io.h" // Include your I/O header for port access
+#include "io.h"
 #include "vga.h"
 
 // Initialize the display
 void init_display(void) {
-    // 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
+    // Initialize the VGA driver. This typically sets up the 80x25 text mode,
+    // clears the screen, and sets the cursor.
+    vga_init();
 }
 
 // Enumerate connected displays
 void enumerate_displays(void) {
-    // This is a simplified example. Actual enumeration may require
-    // reading from specific VGA registers or using BIOS interrupts.
+    // 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.
     
-    // 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
+    // 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.
 }
 
 // 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) {
-    // Set the VGA mode by writing to the appropriate registers
-    outb(VGA_PORT, mode); // Example function to write to a port
+    // 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);
+    }
 }
 
 // Clear the display
 void clear_display(void) {
-    // 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
+    // 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);
 }

kernel/display.h

@@ -2,13 +2,21 @@
 #define DISPLAY_H
 
 #include <stdint.h>
+#include "vga.h" // Include VGA functions
 
-#define VGA_PORT 0x3C0  // Base port for VGA
+#define VGA_PORT 0x3C0  // Base port for VGA (Often used for general control, though 0x3D4/0x3D5 are used for cursor)
 
 // Function prototypes
 void init_display(void);
 void enumerate_displays(void);
-void set_display_mode(uint8_t mode);
+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 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

@@ -0,0 +1,107 @@
+#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

@@ -0,0 +1,60 @@
+#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

@@ -0,0 +1,66 @@
+#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

@@ -0,0 +1,34 @@
+#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

@@ -0,0 +1,65 @@
+#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

@@ -0,0 +1,46 @@
+#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

@@ -2,64 +2,91 @@
 #include "io.h"
 #include "isr.h"
 #include "terminal.h"
+#include <stddef.h>
 
 #define KEYBOARD_DATA_PORT 0x60
 #define KEY_BUFFER_SIZE 256
 
-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;
+// 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;
 
-// 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
+// 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
 };
 
-// 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];
+/**
+ * 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) {
     if (!c) return;
 
     uint8_t next_head = (buffer_head + 1) % KEY_BUFFER_SIZE;
 
-    // Drop key if buffer full
-    if (next_head == buffer_tail) return;
+    // If buffer is full, we must drop the key
+    if (next_head == buffer_tail) {
+        return; 
+    }
 
     key_buffer[buffer_head] = c;
     buffer_head = next_head;
     buffer_count++;
 
+    // Echo to terminal
     terminal_putchar(c);
 }
 
-void keyboard_init() {
-    register_interrupt_handler(33, keyboard_callback); // IRQ1 = int 33 (0x21)
+/**
+ * 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);
 }
 
-// Blocking read (returns one char)
+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
+ */
 char keyboard_get_char(void) {
-    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;
+    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"); 
+    }
 }

kernel/keyboard.h

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

kernel/mouse.c

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

kernel/mouse.h

@@ -12,6 +12,8 @@ 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, my_strlen(buffer)); // Use my_strlen instead of strlen
+    vga_write_string(buffer, strlen(buffer)); // Use my_strlen instead of strlen
 }
 
 void vga_init(void) {

kernel/vga.h

@@ -35,6 +35,7 @@ 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);
@@ -50,4 +51,4 @@ void vga_set_cursor_blink_rate(uint8_t rate);
 
 void vga_printf(const char* format, ...);
 
-#endif
+#endif