keyboard.c (2004B)
1 #include "oxytoxin.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_entry(void); 25 26 char keyboard_read(void) { 27 char ch; 28 29 while (1) { 30 asm volatile ("cli"); 31 if (buf_head != buf_tail) { 32 ch = buf[buf_head]; 33 buf_head = (buf_head + 1) % buf_size; 34 asm volatile ("sti"); 35 return ch; 36 } 37 asm volatile ("sti; hlt"); 38 } 39 } 40 41 void keyboard_handler(void) { 42 unsigned char scancode; 43 unsigned int next_tail; 44 char ascii_char; 45 46 scancode = inb(0x60); 47 48 if (scancode == 0x2a || scancode == 0x36) { 49 shift_state = 1; 50 outb(0x20, 0x20); 51 return; 52 } else if (scancode == 0xaa || scancode == 0xb6) { 53 shift_state = 0; 54 outb(0x20, 0x20); 55 return; 56 } 57 58 59 if (scancode < 0x80) { 60 if (shift_state) { 61 ascii_char = upper_scancodes[scancode]; 62 } else { 63 ascii_char = lower_scancodes[scancode]; 64 } 65 66 if (ascii_char != 0) { 67 next_tail = (buf_tail + 1) % buf_size; 68 if (next_tail != buf_head) { 69 buf[buf_tail] = ascii_char; 70 buf_tail = next_tail; 71 } 72 } 73 } 74 75 outb(0x20, 0x20); 76 } 77 78 void keyboard_init(void) { 79 idt_register(33, keyboard_entry); 80 }