adding and fixing some missing things and some undefined

kernel/keyboard.c

@@ -0,0 +1,53 @@
+#include "keyboard.h"
+#include "io.h"
+#include "isr.h"
+#include "terminal.h"
+
+#define KEYBOARD_DATA_PORT 0x60
+
+static char key_buffer[256];
+static uint8_t buffer_index = 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, '\\', 'y', 'x', 'c', 'v', 'b', // 0x28 - 0x31
+   'n', 'm', ',', '.', '/', 0, '*', 0, ' ', 0,      // 0x32 - 0x3B
+    // rest can be filled as needed
+};
+
+// Interrupt handler for IRQ1
+void keyboard_callback() {
+    uint8_t scancode = inb(KEYBOARD_DATA_PORT);
+
+    // Ignore key releases (scancodes with high bit set)
+    if (scancode & 0x80)
+        return;
+
+    char c = scancode_map[scancode];
+    if (c && buffer_index < sizeof(key_buffer)) {
+        key_buffer[buffer_index++] = c;
+        terminal_putchar(c); // Echo to terminal (optional)
+    }
+}
+
+void keyboard_init() {
+    register_interrupt_handler(33, keyboard_callback); // IRQ1 = int 33 (0x21)
+}
+
+// Blocking read (returns one char)
+char keyboard_get_char() {
+    while (buffer_index == 0);
+    char c = key_buffer[0];
+
+    // Shift buffer left
+    for (uint8_t i = 1; i < buffer_index; i++) {
+        key_buffer[i - 1] = key_buffer[i];
+    }
+    buffer_index--;
+
+    return c;
+}