openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity
linux/Documentation/fb/internals.rst

87 lines
2.7 KiB
ReStructuredText
Raw Normal View History

docs: fb: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:52:45 +08:00
=============================
Frame Buffer device internals
=============================
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
This is a first start for some documentation about frame buffer device
internals.
docs: fb: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:52:45 +08:00
Authors:
- Geert Uytterhoeven <geert@linux-m68k.org>, 21 July 1998
- James Simmons <jsimmons@user.sf.net>, Nov 26 2002
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
--------------------------------------------------------------------------------
docs: fb: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:52:45 +08:00
Structures used by the frame buffer device API
==============================================
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
The following structures play a role in the game of frame buffer devices. They
are defined in <linux/fb.h>.
1. Outside the kernel (user space)
- 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.
- 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.
- struct fb_cmap
Device independent colormap information. You can get and set the colormap
using the FBIOGETCMAP and FBIOPUTCMAP ioctls.
2. Inside the kernel
- struct fb_info
Generic information, API and low level information about a specific frame
buffer device instance (slot number, board address, ...).
docs: fb: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:52:45 +08:00
- struct `par`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
Device dependent information that uniquely defines the video mode for this
particular piece of hardware.
docs: fb: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:52:45 +08:00
Visuals used by the frame buffer device API
===========================================
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
Monochrome (FB_VISUAL_MONO01 and FB_VISUAL_MONO10)
docs: fb: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:52:45 +08:00
--------------------------------------------------
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
Each pixel is either black or white.
Pseudo color (FB_VISUAL_PSEUDOCOLOR and 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.
True color (FB_VISUAL_TRUECOLOR)
--------------------------------
The pixel value is broken up into red, green, and blue fields.
Direct color (FB_VISUAL_DIRECTCOLOR)
------------------------------------
docs: fb: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:52:45 +08:00
The pixel value is broken up into red, green, and blue fields, each of which
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
are looked up in separate red, green, and blue lookup tables.
Grayscale displays
------------------
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.