kernel-ark/drivers/video/console/Kconfig
Antonino A. Daplas e4fc27618b [PATCH] fbcon: Console Rotation - Prepare fbcon for console rotation
This patch series implements generic code to rotate the console at 90, 180,
and 270 degrees. The implementation is completely done in the framebuffer
console level, thus no changes to the framebuffer layer or to the drivers
are needed.

Console rotation is required by some Sharp-based devices where the natural
orientation of the display is not at 0 degrees. Also, users that have
displays that can pivot will benefit by having a console in portrait mode
if they so desire.

The choice to implement the code in the console layer rather than in the
framebuffer layer is due to the following reasons:

- it's fast
- it does not require driver changes
- it can coexist with devices that can rotate the display at the hardware level
- it complements graphics applications that can do display rotation

The changes to core fbcon are minimal-- recognition of the console
rotation angle so it can swap directions, origins and axes (xres vs yres,
xpanstep vs ypanstep, xoffset vs yoffset, etc) and storage of the rotation
angle per display. The bulk of the code that does the actual drawing to the
screen are placed in separate files. Each angle of rotation has separate
methods (bmove, clear, putcs, cursor, update_start which is derived from
update_var, and clear_margins).  To mimimize processing time, the fontdata
are pre-rotated at each console switch (only if the font or the angle has
changed).

The option can be compiled out (CONFIG_FRAMEBUFFER_CONSOLE_ROTATION = n) if
rotation is not needed.

Choosing the rotation angle can be done in several ways:

1. boot option fbcon=rotate:n, where
     n = 0 - normal
     n = 1 - 90 degrees (clockwise)
     n = 2 - 180 degrees (upside down)
     n = 3 - 270 degrees (counterclockwise)

2. echo n > /sys/class/graphics/fb[num]/con_rotate

     where n is the same as described above. It sets the angle of rotation
of the current console

3 echo n > /sys/class/graphics/fb[num]/con_rotate_all

     where n is the same as described above. Globally sets the angle of
rotation.

GOTCHAS:

	The option, especially at angles of 90 and 270 degrees, will exercise
the least used code of drivers.  Namely, at these angles, panning is done
in the x-axis, so it can reveal bugs in the driver if xpanstep is set
incorrectly. A workaround is to set xpanstep = 0.

	Secondly, at these angles, the framebuffer memory access can be
unaligned if (fontheight * bpp) % 32 ~= 0 which can reveal bugs in the drivers
imageblit, fillrect and copyarea functions.  (I think cfbfillrect may have
this buglet). A workaround is to use a standard 8x16 font.

Speed:

	The scrolling speed difference between 0 and 180 degrees is minimal,
somewhere areound 1-2%.  At 90 or 270 degress, speed drops down to a vicinity
of 30-40%. This is understandable because the blit direction is across the
framebuffer "direction." Scrolling will be helped at these angles if xpanstep
is not equal to zero, use of 8x16 fonts, and setting xres_virtual >= xres * 2.

Note: The code is tested on little-endian only, so I don't know if it will
work in big-endian. Please let me know, it will take only less than a minute
of your time.

This patch prepares fbcon for console rotation and contains the following
changes:

- add rotate field in struct fbcon_ops to keep fbcon's current rotation
  angle

- add con_rotate field in struct display to store per-display rotation angle

- create a private copy of the current var to fbcon.  This will prevent
  fbcon from directly manipulating info->var, especially the fields xoffset,
  yoffset and vmode.

- add ability to swap pertinent axes (xres, yres; xpanstep, ypanstep; etc)
  depending on the rotation angle

- change global update_var() (function that sets the screen start address)
  as an fbcon method update_start.  This is required because the axes, start
  offset, and/or direction can be reversed depending on the rotation angle.

- add fbcon method rotate_font() which will rotate each character bitmap to
  the correct angle of rotation.

- add fbcon boot option 'rotate' to select the angle of rotation at bootime.
   Currently does nothing until all patches are applied.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:34 -08:00

227 lines
7.6 KiB
Plaintext

#
# Video configuration
#
menu "Console display driver support"
config VGA_CONSOLE
bool "VGA text console" if EMBEDDED || !X86
depends on !ARCH_ACORN && !ARCH_EBSA110 && !4xx && !8xx && !SPARC32 && !SPARC64 && !M68K && !PARISC && !ARCH_VERSATILE
default y
help
Saying Y here will allow you to use Linux in text mode through a
display that complies with the generic VGA standard. Virtually
everyone wants that.
The program SVGATextMode can be used to utilize SVGA video cards to
their full potential in text mode. Download it from
<ftp://ibiblio.org/pub/Linux/utils/console/>.
Say Y.
# if [ "$CONFIG_PCI" = "y" -a "$CONFIG_VGA_CONSOLE" = "y" ]; then
# bool ' Allow VGA on any bus?' CONFIG_VGA_HOSE
# if [ "$CONFIG_VGA_HOSE" = "y" ]; then
# define_bool CONFIG_DUMMY_CONSOLE y
# fi
# fi
config VIDEO_SELECT
bool "Video mode selection support"
depends on X86 && VGA_CONSOLE
---help---
This enables support for text mode selection on kernel startup. If
you want to take advantage of some high-resolution text mode your
card's BIOS offers, but the traditional Linux utilities like
SVGATextMode don't, you can say Y here and set the mode using the
"vga=" option from your boot loader (lilo or loadlin) or set
"vga=ask" which brings up a video mode menu on kernel startup. (Try
"man bootparam" or see the documentation of your boot loader about
how to pass options to the kernel.)
Read the file <file:Documentation/svga.txt> for more information
about the Video mode selection support. If unsure, say N.
config MDA_CONSOLE
depends on !M68K && !PARISC && ISA
tristate "MDA text console (dual-headed) (EXPERIMENTAL)"
---help---
Say Y here if you have an old MDA or monochrome Hercules graphics
adapter in your system acting as a second head ( = video card). You
will then be able to use two monitors with your Linux system. Do not
say Y here if your MDA card is the primary card in your system; the
normal VGA driver will handle it.
To compile this driver as a module, choose M here: the
module will be called mdacon.
If unsure, say N.
config SGI_NEWPORT_CONSOLE
tristate "SGI Newport Console support"
depends on SGI_IP22
help
Say Y here if you want the console on the Newport aka XL graphics
card of your Indy. Most people say Y here.
# bool 'IODC console' CONFIG_IODC_CONSOLE
config PROM_CONSOLE
bool "PROM console"
depends on SPARC32 || SPARC64
help
Say Y to build a console driver for Sun machines that uses the
terminal emulation built into their console PROMS.
config DUMMY_CONSOLE
bool
depends on PROM_CONSOLE!=y || VGA_CONSOLE!=y || SGI_NEWPORT_CONSOLE!=y
default y
config DUMMY_CONSOLE_COLUMNS
int "Initial number of console screen columns"
depends on PARISC && DUMMY_CONSOLE
default "160"
help
The default value is 160, which should fit a 1280x1024 monitor.
Select 80 if you use a 640x480 resolution by default.
config DUMMY_CONSOLE_ROWS
int "Initial number of console screen rows"
depends on PARISC && DUMMY_CONSOLE
default "64"
help
The default value is 64, which should fit a 1280x1024 monitor.
Select 25 if you use a 640x480 resolution by default.
config FRAMEBUFFER_CONSOLE
tristate "Framebuffer Console support"
depends on FB
select CRC32
help
Low-level framebuffer-based console driver.
config FRAMEBUFFER_CONSOLE_ROTATION
bool "Framebuffer Console Rotation"
depends on FRAMEBUFFER_CONSOLE
help
Enable display rotation for the framebuffer console. This is done
in software and may be significantly slower than a normally oriented
display. Note that the rotation is done at the console level only
such that other users of the framebuffer will remain normally
oriented.
config STI_CONSOLE
tristate "STI text console"
depends on PARISC
default y
help
The STI console is the builtin display/keyboard on HP-PARISC
machines. Say Y here to build support for it into your kernel.
The alternative is to use your primary serial port as a console.
config FONTS
bool "Select compiled-in fonts"
depends on FRAMEBUFFER_CONSOLE || STI_CONSOLE
help
Say Y here if you would like to use fonts other than the default
your frame buffer console usually use.
Note that the answer to this question won't directly affect the
kernel: saying N will just cause the configurator to skip all
the questions about foreign fonts.
If unsure, say N (the default choices are safe).
config FONT_8x8
bool "VGA 8x8 font" if FONTS
depends on FRAMEBUFFER_CONSOLE || STI_CONSOLE
default y if !SPARC32 && !SPARC64 && !FONTS
help
This is the "high resolution" font for the VGA frame buffer (the one
provided by the text console 80x50 (and higher) modes).
Note that this is a poor quality font. The VGA 8x16 font is quite a
lot more readable.
Given the resolution provided by the frame buffer device, answer N
here is safe.
config FONT_8x16
bool "VGA 8x16 font" if FONTS
depends on FRAMEBUFFER_CONSOLE || SGI_NEWPORT_CONSOLE=y || STI_CONSOLE || USB_SISUSBVGA_CON
default y if !SPARC32 && !SPARC64 && !FONTS
help
This is the "high resolution" font for the VGA frame buffer (the one
provided by the VGA text console 80x25 mode.
If unsure, say Y.
config FONT_6x11
bool "Mac console 6x11 font (not supported by all drivers)" if FONTS
depends on FRAMEBUFFER_CONSOLE || STI_CONSOLE
default y if !SPARC32 && !SPARC64 && !FONTS && MAC
help
Small console font with Macintosh-style high-half glyphs. Some Mac
framebuffer drivers don't support this one at all.
config FONT_7x14
bool "console 7x14 font (not supported by all drivers)" if FONTS
depends on FRAMEBUFFER_CONSOLE
help
Console font with characters just a bit smaller than the default.
If the standard 8x16 font is a little too big for you, say Y.
Otherwise, say N.
config FONT_PEARL_8x8
bool "Pearl (old m68k) console 8x8 font" if FONTS
depends on FRAMEBUFFER_CONSOLE
default y if !SPARC32 && !SPARC64 && !FONTS && AMIGA
help
Small console font with PC-style control-character and high-half
glyphs.
config FONT_ACORN_8x8
bool "Acorn console 8x8 font" if FONTS
depends on FRAMEBUFFER_CONSOLE
default y if !SPARC32 && !SPARC64 && !FONTS && ARM && ARCH_ACORN
help
Small console font with PC-style control characters and high-half
glyphs.
config FONT_MINI_4x6
bool "Mini 4x6 font"
depends on !SPARC32 && !SPARC64 && FONTS
config FONT_SUN8x16
bool "Sparc console 8x16 font"
depends on FRAMEBUFFER_CONSOLE && (!SPARC32 && !SPARC64 && FONTS || SPARC32 || SPARC64)
help
This is the high resolution console font for Sun machines. Say Y.
config FONT_SUN12x22
bool "Sparc console 12x22 font (not supported by all drivers)"
depends on FRAMEBUFFER_CONSOLE && (!SPARC32 && !SPARC64 && FONTS || SPARC32 || SPARC64)
help
This is the high resolution console font for Sun machines with very
big letters (like the letters used in the SPARC PROM). If the
standard font is unreadable for you, say Y, otherwise say N.
config FONT_10x18
bool "console 10x18 font (not supported by all drivers)" if FONTS
depends on FRAMEBUFFER_CONSOLE
help
This is a high resolution console font for machines with very
big letters. It fits between the sun 12x22 and the normal 8x16 font.
If other fonts are too big or too small for you, say Y, otherwise say N.
config FONT_RL
bool "console Roman Large 8x16 font" if FONTS
depends on FRAMEBUFFER_CONSOLE
help
This is the visually-appealing "RL" console font that is
included with the kbd package.
endmenu