sgicons.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 * sgicons.c: Setting up and registering console I/O on the SGI.
 *
 * Copyright (C) 1996 David S. Miller ([e-mail])
 * Copyright (C) 1997 Miguel de Icaza ([e-mail])
 *
 * This implements a virtual console interface.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <asm/uaccess.h>
#include "gconsole.h"

/* This is the system graphics console (the first adapter found) */
struct console_ops *gconsole = 0;
struct console_ops *real_gconsole = 0;

void
enable_gconsole (void)
{
	if (!gconsole)
		gconsole = real_gconsole;
}

void
disable_gconsole (void)
{
	if (gconsole){
		real_gconsole = gconsole;
		gconsole = 0;
	}
}

EXPORT_SYMBOL(disable_gconsole);
EXPORT_SYMBOL(enable_gconsole);

void
register_gconsole (struct console_ops *gc)
{
	if (gconsole)
		return;
	gconsole = gc;
}