==================================
ϡ
linux-2.6.13-rc5/Documentation/fb/internals.txt 
Ǥ
Ρ JF ץ < http://www.linux.or.jp/JF/ >
  2005/8/28
: Geert Uytterhoeven <geert at linux-m68k dot org>
          James Simmons <jsimmons at user dot sf dot net> 
  Hiroshi.Suzuki < setter at reset dot jp >
  Masanori Kobayasi  <zap03216 at nifty dot ne dot jp>
         Seiji Kaneko  <skaneko at a2 dot mbn dot or dot jp>
==================================

This is a first start for some documentation about frame buffer device
internals.

ϡե졼ХåեǥХ˴ؤ뤤ĤΤκǽΰǤ

Geert Uytterhoeven <geert at linux-m68k dot org>, 21 July 1998
James Simmons <jsimmons at user dot sf dot net>, Nov 26 2002

--------------------------------------------------------------------------------

	    ***  STRUCTURES USED BY THE FRAME BUFFER DEVICE API  ***

	    *** ե졼ХåեǥХ API ǻѤ빽¤ ***

The following structures play a role in the game of frame buffer devices. They
are defined in <linux/fb.h>.

˼¤Τϡե졼ХåեǥХȤǡ餸ΤǤ
ϡ<linux/fb.h> Ƥޤ

1. Outside the kernel (user space)

1. ͥγ¦ (桼)

  - struct fb_fix_screeninfo

    Device independent unchangeable information about a frame buffer device and
    a specific video mode. This can be obtained using the FBIOGET_FSCREENINFO
    ioctl.

   ǥХ¸Υե졼ХåեǥХˤĤƤѹǽʡȸͭΥӥǥ⡼ɡ
   FBIOGET_FSCREENINFO ioctl ޤ

  - struct fb_var_screeninfo

    Device independent changeable information about a frame buffer device and a
    specific video mode. This can be obtained using the FBIOGET_VSCREENINFO
    ioctl, and updated with the FBIOPUT_VSCREENINFO ioctl. If you want to pan
    the screen only, you can use the FBIOPAN_DISPLAY ioctl.

    ǥХ¸Υե졼ХåեǥХˤĤƤѹǽʾȡͭΥӥǥ⡼ɡ
    FBIOGET_VSCREENINFO ioctl ǼǤFBIOPUT_VSCREENINFO ioctl ǹޤ
    ̤ѥ󤷤ʤ顢FBIOPAN_DISPLAY ioctl Ȥޤ

  - struct fb_cmap

    Device independent colormap information. You can get and set the colormap
    using the FBIOGETCMAP and FBIOPUTCMAP ioctls.

    ǥХ¸Υ顼ޥå׾FBIOGETCMAP  FBIOPUTCMAP ioctls Ȥ
    顼ޥåפ򡢼/Ǥޤ

2. Inside the kernel

2. ͥ

  - struct fb_info

    Generic information, API and low level information about a specific frame
    buffer device instance (slot number, board address, ...).

    ŪʾǡΥե졼ХåեǥХ󥹥 (åֹ桤ܡɥɥ쥹, ...)
    ˴ؤ롢API ٥ʾ

  - struct `par'

    Device dependent information that uniquely defines the video mode for this
    particular piece of hardware.

    ϡɥʬΥӥǥ⡼ɤŪǥХ¸ξ

--------------------------------------------------------------------------------

	    ***  VISUALS USED BY THE FRAME BUFFER DEVICE API  ***

	    *** ե졼ХåեǥХ API ǻȤӥ奢 ***

Monochrome (FB_VISUAL_MONO01 and FB_VISUAL_MONO10)

 (FB_VISUAL_MONO01  FB_VISUAL_MONO10)
-------------------------------------------------
Each pixel is either black or white.

줾βǤϡΤɤ餫

Pseudo color (FB_VISUAL_PSEUDOCOLOR and FB_VISUAL_STATIC_PSEUDOCOLOR)

顼 (FB_VISUAL_PSEUDOCOLOR  FB_VISUAL_STATIC_PSEUDOCOLOR)
---------------------------------------------------------------------
The whole pixel value is fed through a programmable lookup table that has one
color (including red, green, and blue intensities) for each possible pixel
value, and that color is displayed.

٤ƤβͤϡġѲǽʲͤ1Ĥο (֡СĤζ٤) 
ץޥ֥ʥååץơ֥ͳǶ뤵졢ɽޤ


True color (FB_VISUAL_TRUECOLOR)

ȥ롼顼 (FB_VISUAL_TRUECOLOR)
--------------------------------
The pixel value is broken up into red, green, and blue fields.

ͤϡ֡СĤΥեɤʬ򤵤ޤ

Direct color (FB_VISUAL_DIRECTCOLOR)

쥯ȥ顼 (FB_VISUAL_DIRECTCOLOR)
------------------------------------
The pixel value is broken up into red, green, and blue fields, each of which 
are looked up in separate red, green, and blue lookup tables.

ͤϡ֡СĤΥեɤʬ򤵤졢줾̡ˡ֡С Υåå
ơ֥򸫤ޤ

Grayscale displays

졼ǥץ쥤
------------------
Grayscale and static grayscale are special variants of pseudo color and static
pseudo color, where the red, green and blue components are always equal to
each other.


쥤ȡŪ졼ϡ顼Ū顼̤ʲǤǡ
֡СĤιǤϡˤߤƱǤ
