Merge pull request #99 from gbowne1/gbowne1-add-hid

Add HID support

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];
+// Use volatile so the compiler knows these change inside interrupts
-static uint8_t buffer_head = 0;  // Write position (interrupt)
+static volatile char key_buffer[KEY_BUFFER_SIZE];
-static uint8_t buffer_tail = 0;  // Read position (get_char)
+static volatile uint8_t buffer_head = 0;
-static uint8_t buffer_count = 0;
+static volatile uint8_t buffer_tail = 0;
-static uint8_t buffer_index = 0;
+static volatile uint8_t buffer_count = 0;
 
-// Basic US QWERTY keymap (scancode to ASCII)
+// Exported map: Removed 'static' so hid.c can reference it if needed
-static const char scancode_map[128] = {
+const char scancode_map[128] = {
-    0,  27, '1', '2', '3', '4', '5', '6', '7', '8', // 0x00 - 0x09
+    0,  27, '1', '2', '3', '4', '5', '6', '7', '8',
-   '9', '0', '-', '=', '\b', '\t', 'q', 'w', 'e', 'r', // 0x0A - 0x13
+    '9', '0', '-', '=', '\b', '\t', 'q', 'w', 'e', 'r',
-   't', 'y', 'z', 'u', 'i', 'o', 'p', '[', ']', '\n', // 0x14 - 0x1D
+    't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n', 0,
-    0, 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', // 0x1E - 0x27
+    'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';',
-   ';', '\'', '`', 0, '\\', 'x', 'c', 'v', 'b', // 0x28 - 0x31
+    '\'', '`', 0, '\\', 'z', 'x', 'c', 'v', 'b', 'n',
-   'n', 'm', ',', '.', '/', 0, '*', 0, ' ', 0,      // 0x32 - 0x3B
+    'm', ',', '.', '/', 0, '*', 0, ' ', 0
-    // rest can be filled as needed
 };
 
-// Interrupt handler for IRQ1
+/**
-void keyboard_callback(void) {
+ * Shared function used by both PS/2 (callback) and USB (hid.c)
-    uint8_t scancode = inb(KEYBOARD_DATA_PORT);
+ * This fixes the "undefined reference to keyboard_buffer_add" error.
-
+ */
-    if (scancode & 0x80) return;  // Ignore key release
+void keyboard_buffer_add(char c) {
-
-    char c = scancode_map[scancode];
     if (!c) return;
 
     uint8_t next_head = (buffer_head + 1) % KEY_BUFFER_SIZE;
 
-    // Drop key if buffer full
+    // If buffer is full, we must drop the key
-    if (next_head == buffer_tail) return;
+    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");
+
+    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");
+            __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);