Keyboard

void con_init(void) // 键盘也是console的一部分
{
	set_trap_gate(0x21, &keyboard_interrupt);
}

// kernel/chr_drv/keyboard.S
.globl _keyboard_interrupt
_keyboard_interrupt:
	inb $0x60,%al  // 从端口0x60读扫描码
	call key_table(,%eax,4)
	...
	push $0
	call _do_tty_interrupt

key_table:
	.long none,do_self,do_self,do_self // 扫描码00-03
	.long do_self, ...,func,scroll,cursor 

key_map:
	.byte 0,27
	.ascii "1234567890-="
	.byte 127,9
	.ascii "qwertyuiop[]"
	.byte 13,0
	.ascii "asdfghjkl;'"
	.byte '`,0
	.ascii "\\zxcvbnm,./"
	.byte 0,'*,0,32		/* 36-39 */
	.fill 16,1,0		
	.byte '-,0,0,0,'+	
	.byte 0,0,0,0,0,0,0	
	.byte '<
	.fill 10,1,0

do_self:
	lea alt_map,%ebx
	testb $0x20,mode		// alt键是否同时按下
	jne 1f
	lea shift_map,%ebx
	testb $0x03,mode
	jne 1f
	lea key_map,%ebx
1:	movb (%ebx,%eax),%al  // 扫描码索引，ascii码-> al
	orb %al,%al
	je none  // 没有对应的ascii码
	testb $0x4c,mode		// 是否大写锁定
	je 2f
	cmpb $'a,%al
	jb 2f
	cmpb $'},%al
	ja 2f
	subb $32,%al
2:	testb $0x0c,mode		// 处理其他模式
	je 3f
	cmpb $64,%al
	jb 3f
	cmpb $64+32,%al
	jae 3f
	subb $64,%al
3:	testb $0x10,mode		
	je 4f
	orb $0x80,%al
4:	andl $0xff,%eax
	xorl %ebx,%ebx
	call put_queue
none:	ret

put_queue:
	pushl %ecx
	pushl %edx
	movl table_list,%edx		# read-queue for console
	movl head(%edx),%ecx
1:	movb %al,buf(%edx,%ecx)

void do_tty_interrupt(int tty) // 上面传入的是0
{
	copy_to_cooked(tty_table+tty);
}

void copy_to_cooked(struct tty_struct *tty)
{
	GETCH(tty->read_q,c);
	if(L_ECHO(tty)) {  // 回显
		PUTCH(c,tty->write_q);
		tty->write(tty);
	}
	PUTCH(c,tty->secondary);
	...
	wake_up(&tty->secondary.proc_list);
}