keyboard.c (1958B)
1 #include <fns.h> 2 #include "keyboard.h" 3 4 unsigned int shift_state = 0; 5 6 unsigned char buf[buf_size]; 7 unsigned int buf_head = 0; 8 unsigned int buf_tail = 0; 9 10 const char lower_scancodes[128] = { 11 0, 0, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', 12 '=', '\b', '\t', 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', 13 '[', ']', '\n', 0, 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', 14 ';', '\'', '`', 0, '\\', 'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', 15 '.', '/', 0, '*', 0, ' ', 0, 0, 0, 0, 0, 0}; 16 17 const char upper_scancodes[128] = { 18 0, 0, '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', 19 '+', '\b', '\t', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', 20 '{', '}', '\n', 0, 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', 21 ':', '\"', '~', 0, '|', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', 22 '>', '?', 0, '*', 0, ' ', 0, 0, 0, 0, 0, 0}; 23 24 extern void keyboard_asm(void); 25 26 char keyboard_read(void) { 27 while (1) { 28 asm volatile("cli"); 29 if (buf_head != buf_tail) { 30 char ch = buf[buf_head]; 31 buf_head = (buf_head + 1) % buf_size; 32 asm volatile("sti"); 33 return ch; 34 } 35 asm volatile("sti; hlt"); 36 } 37 } 38 39 void keyboard_handler(void) { 40 unsigned char scancode = inb(0x60); 41 42 if (scancode == 0x2a || scancode == 0x36) { 43 shift_state = 1; 44 outb(0x20, 0x20); 45 return; 46 } else if (scancode == 0xaa || scancode == 0xb6) { 47 shift_state = 0; 48 outb(0x20, 0x20); 49 return; 50 } 51 52 if (scancode < 0x80) { 53 char ascii_char; 54 55 if (shift_state) { 56 ascii_char = upper_scancodes[scancode]; 57 } else { 58 ascii_char = lower_scancodes[scancode]; 59 } 60 61 if (ascii_char != 0) { 62 unsigned int next_tail = (buf_tail + 1) % buf_size; 63 if (next_tail != buf_head) { 64 buf[buf_tail] = ascii_char; 65 buf_tail = next_tail; 66 } 67 } 68 } 69 70 outb(0x20, 0x20); 71 } 72 73 void keyboard_init() { 74 idt_register(33, keyboard_asm); 75 }