framebuffer 子系统结构

 struct fb_info {

    
 	int node;
    
 	int flags;
    
 	struct mutex lock;		/* 调用open/release/ioctl时的锁 */
    
 	struct mutex mm_lock;		/* fb_mmap和smem_*的锁 */
    
 	struct fb_var_screeninfo var;	/* 当前LCD的可变参数 */
    
 	struct fb_fix_screeninfo fix;	/* 当前LCD的固定参数 */
    
 	struct fb_monspecs monspecs;	/* 当前LCD标准 */
    
 	struct work_struct queue;	/* 帧缓冲工作队列 */
    
 	struct fb_pixmap pixmap;	/* 图像硬件mapper */
    
 	struct fb_pixmap sprite;	/* 光标硬件mapper */
    
 	struct fb_cmap cmap;		/* 当前LCD的颜色表 */
    
 	struct list_head modelist;      /* mode list */
    
 	struct fb_videomode *m