FrameBuffer的重要数据结构

struct fb_fix_screeninfo {

char id[16]; /* identification string eg "TT Builtin" */

unsigned long smem_start; /* Start of frame buffer mem */
/* (physical address) */

__u32 smem_len; /* Length of frame buffer mem */

__u32 type; /* see FB_TYPE_* */

__u32 type_aux; /* Interleave for interleaved Planes */

__u32 visual; /* see FB_VISUAL_* */

__u16 xpanstep; /* zero if no hardware panning */

__u16 ypanstep; /* zero if no hardware panning */

__u16 ywrapstep; /* zero if no hardware ywrap */

__u32 line_length; /* length of a line in bytes */

unsigned long mmio_start; /* Start of Memory Mapped I/O */
/* (physical address) */

__u32 mmio_len; /* Length of Memory Mapped I/O */

__u32 aclearcase/" target="_blank" >ccel; /* Type of acceleration available */

__u16 reserved[3]; /* Reserved for future compatibility */

};


struct fb_bitfield {

__u32 offset; /* beginning of bitfield */

__u32 length; /* length of bitfield */

__u32 msb_right; /* != 0 : Most significant bit is */
/* right */

};


struct fb_info {

char modename[40]; /* default video mode */

kdev_t node;

int flags;
int open; /* Has this been open already ? */

#define FBINFO_FLAG_MODULE 1 /* Low-level driver is a module */

struct fb_var_screeninfo var; /* Current var */

struct fb_fix_screeninfo fix; /* Current fix */

struct fb_monspecs monspecs; /* Current Monitor specs */

struct fb_cmap cmap; /* Current cmap */

struct fb_ops *fbops;

char *screen_base; /* Virtual address */

struct display *disp; /* initial display variable */

struct vc_data *display_fg; /* Console visible on this display */

char fontname[40]; /* default font name */

devfs_handle_t devfs_handle; /* Devfs handle for new name */

devfs_handle_t devfs_lhandle; /* Devfs handle for compat. symlink */

int (*changevar)(int); /* tell console var has changed */

int (*switch_con)(int, struct fb_info*);

/* tell fb to switch consoles */

int (*updatevar)(int, struct fb_info*);
/* tell fb to update the vars */

void (*blank)(int, struct fb_info*); /* tell fb to (un)blank the screen */
/* arg = 0: unblank */
/* arg > 0: VESA level (arg-1) */

void *pseudo_palette; /* Fake palette of 16 colors and
the cursor's color for non
palette mode */
/* From here on everything is device dependent */

void *par;

};


struct fbgen_hwswitch {

void (*detect)(void);

int (*encode_fix)(struct fb_fix_screeninfo *fix, const void *par,
struct fb_info_gen *info);

int (*decode_var)(const struct fb_var_screeninfo *var, void *par,
struct fb_info_gen *info);

int (*encode_var)(struct fb_var_screeninfo *var, const void *par,
struct fb_info_gen *info);

void (*get_par)(void *par, struct fb_info_gen *info);

void (*set_par)(const void *par, struct fb_info_gen *info);

int (*getcolreg)(unsigned regno, unsigned *red, unsigned *green,
unsigned *blue, unsigned *transp, struct fb_info *info);

int (*setcolreg)(unsigned regno, unsigned red, unsigned green,
unsigned blue, unsigned transp, struct fb_info *info);

int (*pan_display)(const struct fb_var_screeninfo *var,
struct fb_info_gen *info);

int (*blank)(int blank_mode, struct fb_info_gen *info);

void (*set_disp)(const void *par, struct display *disp,
struct fb_info_gen *info);

};


struct fb_info_gen {

struct fb_info info;

/* Entries for a generic frame buffer device */
/* Yes, this starts looking like C++ */
u_int parsize;

struct fbgen_hwswitch *fbhw;

/* From here on everything is device dependent */

};

原文转自：http://www.ltesting.net