stdio_console.c

来自「优龙2410linux2.6.8内核源代码」· C语言 代码 · 共 250 行

/* 
 * Copyright (C) 2000, 2001 Jeff Dike ([e-mail])
 * Licensed under the GPL
 */

#include "linux/config.h"
#include "linux/posix_types.h"
#include "linux/tty.h"
#include "linux/tty_flip.h"
#include "linux/types.h"
#include "linux/major.h"
#include "linux/kdev_t.h"
#include "linux/console.h"
#include "linux/string.h"
#include "linux/sched.h"
#include "linux/list.h"
#include "linux/init.h"
#include "linux/interrupt.h"
#include "linux/slab.h"
#include "asm/current.h"
#include "asm/hardirq.h"
#include "asm/irq.h"
#include "stdio_console.h"
#include "line.h"
#include "chan_kern.h"
#include "user_util.h"
#include "kern_util.h"
#include "irq_user.h"
#include "mconsole_kern.h"
#include "init.h"
#include "2_5compat.h"

#define MAX_TTYS (8)

/* Referenced only by tty_driver below - presumably it's locked correctly
 * by the tty driver.
 */

static struct tty_driver *console_driver;

static struct chan_ops init_console_ops = {
	.type		= "you shouldn't see this",
	.init  		= NULL,
	.open  		= NULL,
	.close 		= NULL,
	.read  		= NULL,
	.write 		= NULL,
	.console_write 	= generic_write,
	.window_size 	= NULL,
	.free  		= NULL,
	.winch		= 0,
};

static struct chan init_console_chan = {
	.list  		= { },
	.primary 	= 1,
	.input 		= 0,
	.output 	= 1,
	.opened 	= 1,
	.fd 		= 1,
	.pri 		= INIT_STATIC,
	.ops 		= &init_console_ops,
	.data 		= NULL
};

void stdio_announce(char *dev_name, int dev)
{
	printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
	       dev_name);
}

static struct chan_opts opts = {
	.announce 	= stdio_announce,
	.xterm_title	= "Virtual Console #%d",
	.raw		= 1,
	.tramp_stack 	= 0,
	.in_kernel 	= 1,
};

static int con_config(char *str);
static int con_get_config(char *dev, char *str, int size, char **error_out);
static int con_remove(char *str);

static struct line_driver driver = {
	.name 			= "UML console",
	.devfs_name 		= "vc/%d",
	.major 			= TTY_MAJOR,
	.minor_start 		= 0,
	.type 		 	= TTY_DRIVER_TYPE_CONSOLE,
	.subtype 	 	= SYSTEM_TYPE_CONSOLE,
	.read_irq 		= CONSOLE_IRQ,
	.read_irq_name 		= "console",
	.write_irq 		= CONSOLE_WRITE_IRQ,
	.write_irq_name 	= "console-write",
	.symlink_from 		= "ttys",
	.symlink_to 		= "vc",
	.mc  = {
		.name  		= "con",
		.config 	= con_config,
		.get_config 	= con_get_config,
		.remove 	= con_remove,
	},
};

static struct lines console_lines = LINES_INIT(MAX_TTYS);

/* The array is initialized by line_init, which is an initcall.  The 
 * individual elements are protected by individual semaphores.
 */
struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
			      [ 1 ... MAX_TTYS - 1 ] = 
			      LINE_INIT(CONFIG_CON_CHAN, &driver) };

static int con_config(char *str)
{
	return(line_config(vts, sizeof(vts)/sizeof(vts[0]), str));
}

static int con_get_config(char *dev, char *str, int size, char **error_out)
{
	return(line_get_config(dev, vts, sizeof(vts)/sizeof(vts[0]), str, 
			       size, error_out));
}

static int con_remove(char *str)
{
	return(line_remove(vts, sizeof(vts)/sizeof(vts[0]), str));
}

static int open_console(struct tty_struct *tty)
{
	return(line_open(vts, tty, &opts));
}

static int con_open(struct tty_struct *tty, struct file *filp)
{
	return(open_console(tty));
}

static void con_close(struct tty_struct *tty, struct file *filp)
{
	line_close(vts, tty);
}

static int con_write(struct tty_struct *tty, int from_user, 
		     const unsigned char *buf, int count)
{
	 return(line_write(vts, tty, from_user, buf, count));
}

static void set_termios(struct tty_struct *tty, struct termios * old)
{
}

static int chars_in_buffer(struct tty_struct *tty)
{
	return(0);
}

static int con_init_done = 0;

int stdio_init(void)
{
	char *new_title;

	printk(KERN_INFO "Initializing stdio console driver\n");

	console_driver = line_register_devfs(&console_lines, &driver,
				&console_ops, vts, sizeof(vts)/sizeof(vts[0]));

	lines_init(vts, sizeof(vts)/sizeof(vts[0]));

	new_title = add_xterm_umid(opts.xterm_title);
	if(new_title != NULL) opts.xterm_title = new_title;

	open_console(NULL);
	con_init_done = 1;
	return(0);
}

__initcall(stdio_init);

static void console_write(struct console *console, const char *string, 
			  unsigned len)
{
	if(con_init_done) down(&vts[console->index].sem);
	console_write_chan(&vts[console->index].chan_list, string, len);
	if(con_init_done) up(&vts[console->index].sem);
}

static struct tty_operations console_ops = {
	.open 	 		= con_open,
	.close 	 		= con_close,
	.write 	 		= con_write,
	.chars_in_buffer 	= chars_in_buffer,
	.set_termios 		= set_termios,
	.write_room		= line_write_room,
};

static struct tty_driver *console_device(struct console *c, int *index)
{
	*index = c->index;
	return console_driver;
}

static int console_setup(struct console *co, char *options)
{
	return(0);
}

static struct console stdiocons = INIT_CONSOLE("tty", console_write, 
					       console_device, console_setup,
					       CON_PRINTBUFFER);

static void __init stdio_console_init(void)
{
	INIT_LIST_HEAD(&vts[0].chan_list);
	list_add(&init_console_chan.list, &vts[0].chan_list);
	register_console(&stdiocons);
}
console_initcall(stdio_console_init);

static int console_chan_setup(char *str)
{
	line_setup(vts, sizeof(vts)/sizeof(vts[0]), str, 1);
	return(1);
}

__setup("con", console_chan_setup);
__channel_help(console_chan_setup, "con");

static void console_exit(void)
{
	if(!con_init_done) return;
	close_lines(vts, sizeof(vts)/sizeof(vts[0]));
}

__uml_exitcall(console_exit);

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-file-style: "linux"
 * End:
 */