tty.h

fairysky系统,是一个小型的内核,模拟linux原始版本的

/*
 * 'tty.h' defines some structures used by tty_io.c and some defines.
 *
 * NOTE! Don't touch this without checking that nothing in rs_io.s or
 * con_io.s breaks. Some constants are hardwired into the system (mainly
 * offsets into 'tty_queue'
 */

#ifndef _TTY_H
#define _TTY_H

#include <termios.h>
#include <fairysky/types.h>

#define TTY_BUF_SIZE 1024

//tty等待队列数据结构
struct tty_queue {
	u32 data;       //等待队列缓存区中当前字符行数
	u32 head;       //缓存区数据头指针
	u32 tail;       //缓存区数据尾指针
	struct task_struct * proc_list;     //等待进程列表
	char buf[TTY_BUF_SIZE];             //队列的缓存区
};

#define INC(a)      ((a) = ((a) + 1) & (TTY_BUF_SIZE - 1))      //a缓存区指针向前移1字节，并循环
#define DEC(a)      ((a) = ((a) - 1) & (TTY_BUF_SIZE - 1))      //a缓存区指针后退移1字节，并循环
#define EMPTY(a)    ((a).head == (a).tail)                      //判断指定缓存区队列是否为空
#define LEFT(a)     (((a).tail - (a).head - 1) & (TTY_BUF_SIZE - 1))    //缓存区还可以妇女方字符的长度
#define LAST(a)     ((a).buf[(TTY_BUF_SIZE - 1) & ((a).head - 1)])      //缓存区中最后一个位置
#define FULL(a)     (! LEFT(a))                                         //缓存区满
#define CHARS(a)    (((a).head - (a).tail) & (TTY_BUF_SIZE - 1))        //缓存区中已存放字符的长度
//从queue队列缓存区中取一字符
#define GETCH(queue, c) do {        \
    c = (queue).buf[(queue).tail];  \
    INC((queue).tail);              \
}while(0)

//往queue队列缓存区中存一字符    
#define PUTCH(c, queue) do {         \
    (queue).buf[(queue).head] = (c);\
    INC((queue).head);              \
}while(0)
    

#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])     //中断附
#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])     //退出附
#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])   //檫除附
#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])     //终止附
#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])       //文件结束附
#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])   //开始附
#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])     //结束附
#define SUSPEND_CHAR(tty) ((tty)->termios.c_cc[VSUSP])  //挂起附

struct tty_struct {
	struct termios termios;     //终端io属性和控制字符数据结构
	int pgrp;                   //所属进程组
	int stopped;                //停止标志
	void (*write)(struct tty_struct * tty);     //tty写函数指针
	struct tty_queue read_q;    //tty读队列
	struct tty_queue write_q;   //tty写队列
	struct tty_queue secondary; //tty规范模式队列
};

extern struct tty_struct tty_table[];

/*	intr=^C		quit=^|		erase=del	kill=^U
	eof=^D		vtime=\0	vmin=\1		sxtc=\0
	start=^Q	stop=^S		susp=^Z		eol=\0
	reprint=^R	discard=^U	werase=^W	lnext=^V
	eol2=\0
*/
#define INIT_C_CC "\003\034\177\025\004\0\1\0\021\023\032\0\022\017\027\026\0"

extern void con_init(void);
extern void tty_init(void);

extern int tty_read(unsigned c, char * buf, int n);
extern int tty_write(unsigned c, char * buf, int n);

extern void con_write(struct tty_struct * tty);

extern void copy_to_cooked(struct tty_struct * tty);
typedef struct kbuf {
    char scan;
    char ascii;
} keybuf;

keybuf keyBufs[254];

int keyHead = 0;
int keyTail = 0;

#define keybdTail (keyBufs+keyTail)
#define keybdHead (keyBufs+keyHead)

void readkey(char *ascii, char *scan );
int keyEmpty(void);

#endif