Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

[This file is cloned from VesaFB. Thanks go to Gerd Knorr]

What is matroxfb?

=================

This is a driver for a graphic framebuffer for Matrox devices on

Alpha, Intel and PPC boxes.

Advantages:

 * It provides a nice large console (128 cols + 48 lines with 1024x768)

   without using tiny, unreadable fonts.

 * You can run XF{68,86}_FBDev or XFree86 fbdev driver on top of /dev/fb0

 * Most important: boot logo :-)

Disadvantages:

 * graphic mode is slower than text mode... but you should not notice

   if you use same resolution as you used in textmode.

How to use it?

==============

Switching modes is done using the video=matroxfb:vesa:... boot parameter

or using `fbset' program.

If you want, for example, enable a resolution of 1280x1024x24bpp you should

pass to the kernel this command line: "video=matroxfb:vesa:0x1BB".

You should compile in both vgacon (to boot if you remove you Matrox from

box) and matroxfb (for graphics mode). You should not compile-in vesafb

unless you have primary display on non-Matrox VBE2.0 device (see

Documentation/fb/vesafb.txt for details).

Currently supported video modes are (through vesa:... interface, PowerMac

has [as addon] compatibility code):

[Graphic modes]

bpp | 640x400  640x480  768x576  800x600  960x720

----+--------------------------------------------

  4 |            0x12             0x102

  8 |  0x100    0x101    0x180    0x103    0x188

 15 |           0x110    0x181    0x113    0x189

 16 |           0x111    0x182    0x114    0x18A

 24 |           0x1B2    0x184    0x1B5    0x18C

 32 |           0x112    0x183    0x115    0x18B

[Graphic modes (continued)]

bpp | 1024x768 1152x864 1280x1024 1408x1056 1600x1200

----+------------------------------------------------

  4 |   0x104             0x106

  8 |   0x105    0x190    0x107     0x198     0x11C

 15 |   0x116    0x191    0x119     0x199     0x11D

 16 |   0x117    0x192    0x11A     0x19A     0x11E

 24 |   0x1B8    0x194    0x1BB     0x19C     0x1BF

 32 |   0x118    0x193    0x11B     0x19B

[Text modes]

text | 640x400  640x480  1056x344  1056x400  1056x480

-----+------------------------------------------------

 8x8 |  0x1C0    0x108     0x10A     0x10B     0x10C

8x16 | 2, 3, 7                       0x109

You can enter these number either hexadecimal (leading `0x') or decimal

(0x100 = 256). You can also use value + 512 to achieve compatibility

with your old number passed to vesafb.

Non-listed number can be achieved by more complicated command-line, for

example 1600x1200x32bpp can be specified by `video=matroxfb:vesa:0x11C,depth:32'.

X11

===

XF{68,86}_FBDev should work just fine, but it is non-accelerated. On non-intel

architectures there are some glitches for 24bpp videomodes. 8, 16 and 32bpp

works fine.

Running another (accelerated) X-Server like XF86_SVGA works too. But (at least)

XFree servers have big troubles in multihead configurations (even on first

head, not even talking about second). Running XFree86 4.x accelerated mga

driver is possible, but you must not enable DRI - if you do, resolution and

color depth of your X desktop must match resolution and color depths of your

virtual consoles, otherwise X will corrupt accelerator settings.

SVGALib

=======

Driver contains SVGALib compatibility code. It is turned on by choosing textual

mode for console. You can do it at boot time by using videomode

2,3,7,0x108-0x10C or 0x1C0. At runtime, `fbset -depth 0' does this work.

Unfortunately, after SVGALib application exits, screen contents is corrupted.

Switching to another console and back fixes it. I hope that it is SVGALib's

problem and not mine, but I'm not sure.

Configuration

=============

You can pass kernel command line options to matroxfb with

`video=matroxfb:option1,option2:value2,option3' (multiple options should be

separated by comma, values are separated from options by `:').

Accepted options:

mem:X    - size of memory (X can be in megabytes, kilobytes or bytes)

           You can only decrease value determined by driver because of

           it always probe for memory. Default is to use whole detected

           memory usable for on-screen display (i.e. max. 8 MB).

disabled - do not load driver; you can use also `off', but `disabled'

           is here too.

enabled  - load driver, if you have `video=matroxfb:disabled' in LILO

           configuration, you can override it by this (you cannot override

           `off'). It is default.

noaccel  - do not use acceleration engine. It does not work on Alphas.

accel    - use acceleration engine. It is default.

nopan    - create initial consoles with vyres = yres, thus disabling virtual

           scrolling.

pan      - create initial consoles as tall as possible (vyres = memory/vxres).

           It is default.

nopciretry - disable PCI retries. It is needed for some broken chipsets,

           it is autodetected for intel's 82437. In this case device does

           not comply to PCI 2.1 specs (it will not guarantee that every

           transaction terminate with success or retry in 32 PCLK).

pciretry - enable PCI retries. It is default, except for intel's 82437.

novga    - disables VGA I/O ports. It is default if BIOS did not enable device.

           You should not use this option, some boards then do not restart

           without power off.

vga      - preserve state of VGA I/O ports. It is default. Driver does not

           enable VGA I/O if BIOS did not it (it is not safe to enable it in

           most cases).

nobios   - disables BIOS ROM. It is default if BIOS did not enable BIOS itself.

           You should not use this option, some boards then do not restart

           without power off.

bios     - preserve state of BIOS ROM. It is default. Driver does not enable

           BIOS if BIOS was not enabled before.

noinit   - tells driver, that devices were already initialized. You should use

           it if you have G100 and/or if driver cannot detect memory, you see

           strange pattern on screen and so on. Devices not enabled by BIOS

           are still initialized. It is default.

init     - driver initializes every device it knows about.

memtype  - specifies memory type, implies 'init'. This is valid only for G200

           and G400 and has following meaning:

             G200: 0 -> 2x128Kx32 chips, 2MB onboard, probably sgram

                   1 -> 2x128Kx32 chips, 4MB onboard, probably sgram

                   2 -> 2x256Kx32 chips, 4MB onboard, probably sgram

                   3 -> 2x256Kx32 chips, 8MB onboard, probably sgram

                   4 -> 2x512Kx16 chips, 8/16MB onboard, probably sdram only

                   5 -> same as above

                   6 -> 4x128Kx32 chips, 4MB onboard, probably sgram

                   7 -> 4x128Kx32 chips, 8MB onboard, probably sgram

             G400: 0 -> 2x512Kx16 SDRAM, 16/32MB

                        2x512Kx32 SGRAM, 16/32MB

                   1 -> 2x256Kx32 SGRAM, 8/16MB

                   2 -> 4x128Kx32 SGRAM, 8/16MB

                   3 -> 4x512Kx32 SDRAM, 32MB

                   4 -> 4x256Kx32 SGRAM, 16/32MB

                   5 -> 2x1Mx32 SDRAM, 32MB

                   6 -> reserved

                   7 -> reserved

           You should use sdram or sgram parameter in addition to memtype

           parameter.

nomtrr   - disables write combining on frame buffer. This slows down driver but

           there is reported minor incompatibility between GUS DMA and XFree

           under high loads if write combining is enabled (sound dropouts).

mtrr     - enables write combining on frame buffer. It speeds up video accesses

           much. It is default. You must have MTRR support enabled in kernel

           and your CPU must have MTRR (f.e. Pentium II have them).

sgram    - tells to driver that you have Gxx0 with SGRAM memory. It has no

           effect without `init'.

sdram    - tells to driver that you have Gxx0 with SDRAM memory.

           It is a default.

inv24    - change timings parameters for 24bpp modes on Millenium and

           Millenium II. Specify this if you see strange color shadows around

           characters.

noinv24  - use standard timings. It is the default.

inverse  - invert colors on screen (for LCD displays)

noinverse - show true colors on screen. It is default.

dev:X    - bind driver to device X. Driver numbers device from 0 up to N,

           where device 0 is first `known' device found, 1 second and so on.

           lspci lists devices in this order.

           Default is `every' known device for driver with multihead support

           and first working device (usually dev:0) for driver without

           multihead support.

nohwcursor - disables hardware cursor (use software cursor instead).

hwcursor - enables hardware cursor. It is default. If you are using

           non-accelerated mode (`noaccel' or `fbset -accel false'), software

           cursor is used (except for text mode).

noblink  - disables cursor blinking. Cursor in text mode always blinks (hw

           limitation).

blink    - enables cursor blinking. It is default.

nofastfont - disables fastfont feature. It is default.

fastfont:X - enables fastfont feature. X specifies size of memory reserved for

             font data, it must be >= (fontwidth*fontheight*chars_in_font)/8.

             It is faster on Gx00 series, but slower on older cards.

grayscale - enable grayscale summing. It works in PSEUDOCOLOR modes (text,

            4bpp, 8bpp). In DIRECTCOLOR modes it is limited to characters

            displayed through putc/putcs. Direct accesses to framebuffer

            can paint colors.

nograyscale - disable grayscale summing. It is default.

cross4MB - enables that pixel line can cross 4MB boundary. It is default for

           non-Millenium.

nocross4MB - pixel line must not cross 4MB boundary. It is default for

             Millenium I or II, because of these devices have hardware

             limitations which do not allow this. But this option is

             incompatible with some (if not all yet released) versions of

             XF86_FBDev.

dfp      - enables digital flat panel interface. This option is incompatible with

           secondary (TV) output - if DFP is active, TV output must be

           inactive and vice versa. DFP always uses same timing as primary

           (monitor) output.

dfp:X    - use settings X for digital flat panel interface. X is number from

           G400 manual, in description of DAC register 0x1F. For normal operation

           you should set all bits to zero, except lowest bit. This lowest bit

           selects who is source of display clocks, whether G400, or panel.

           Default value is now read back from hardware - so you should specify

           this value only if you are also using `init' parameter.

outputs:XYZ - set mapping between CRTC and outputs. Each letter can have value

           of 0 (for no CRTC), 1 (CRTC1) or 2 (CRTC2), and first letter corresponds

           to primary analog output, second letter to the secondary analog output

           and third letter to the DVI output. Default setting is 100 for

           cards below G400 or G400 without DFP, 101 for G400 with DFP, and

           111 for G450 and G550. You can set mapping only on first card,

           use matroxset for setting up other devices.

vesa:X   - selects startup videomode. X is number from 0 to 0x1FF, see table

           above for detailed explanation. Default is 640x480x8bpp if driver

           has 8bpp support. Otherwise first available of 640x350x4bpp,

           640x480x15bpp, 640x480x24bpp, 640x480x32bpp or 80x25 text

           (80x25 text is always available).

If you are not satisfied with videomode selected by `vesa' option, you

can modify it with these options:

xres:X   - horizontal resolution, in pixels. Default is derived from `vesa'

           option.

yres:X   - vertical resolution, in pixel lines. Default is derived from `vesa'

           option.

upper:X  - top boundary: lines between end of VSYNC pulse and start of first

           pixel line of picture. Default is derived from `vesa' option.

lower:X  - bottom boundary: lines between end of picture and start of VSYNC

           pulse. Default is derived from `vesa' option.

vslen:X  - length of VSYNC pulse, in lines. Default is derived from `vesa'

           option.

left:X   - left boundary: pixels between end of HSYNC pulse and first pixel.

           Default is derived from `vesa' option.

right:X  - right boundary: pixels between end of picture and start of HSYNC

           pulse. Default is derived from `vesa' option.

hslen:X  - length of HSYNC pulse, in pixels. Default is derived from `vesa'

           option.

pixclock:X - dotclocks, in ps (picoseconds). Default is derived from `vesa'

             option and from `fh' and `fv' options.

sync:X   - sync. pulse - bit 0 inverts HSYNC polarity, bit 1 VSYNC polarity.

           If bit 3 (value 0x08) is set, composite sync instead of HSYNC is

           generated. If bit 5 (value 0x20) is set, sync on green is turned on.

           Do not forget that if you want sync on green, you also probably

           want composite sync.

           Default depends on `vesa'.

depth:X  - Bits per pixel: 0=text, 4,8,15,16,24 or 32. Default depends on

           `vesa'.

If you know capabilities of your monitor, you can specify some (or all) of

`maxclk', `fh' and `fv'. In this case, `pixclock' is computed so that

pixclock <= maxclk, real_fh <= fh and real_fv <= fv.

maxclk:X - maximum dotclock. X can be specified in MHz, kHz or Hz. Default is

           `don't care'.

fh:X     - maximum horizontal synchronization frequency. X can be specified

           in kHz or Hz. Default is `don't care'.

fv:X     - maximum vertical frequency. X must be specified in Hz. Default is

           70 for modes derived from `vesa' with yres <= 400, 60Hz for

           yres > 400.

Limitations

===========

There are known and unknown bugs, features and misfeatures.

Currently there are following known bugs:

 + SVGALib does not restore screen on exit

 + generic fbcon-cfbX procedures do not work on Alphas. Due to this,

   `noaccel' (and cfb4 accel) driver does not work on Alpha. So everyone

   with access to /dev/fb* on Alpha can hang machine (you should restrict

   access to /dev/fb* - everyone with access to this device can destroy

   your monitor, believe me...).

 + 24bpp does not support correctly XF-FBDev on big-endian architectures.

 + interlaced text mode is not supported; it looks like hardware limitation,

   but I'm not sure.

 + Gxx0 SGRAM/SDRAM is not autodetected.

 + If you are using more than one framebuffer device, you must boot kernel

   with 'video=scrollback:0'.

 + maybe more...

And following misfeatures:

 + SVGALib does not restore screen on exit.

 + pixclock for text modes is limited by hardware to

    83 MHz on G200

    66 MHz on Millennium I

    60 MHz on Millennium II

   Because I have no access to other devices, I do not know specific

   frequencies for them. So driver does not check this and allows you to

   set frequency higher that this. It causes sparks, black holes and other

   pretty effects on screen. Device was not destroyed during tests. :-)

 + my Millennium G200 oscillator has frequency range from 35 MHz to 380 MHz

   (and it works with 8bpp on about 320 MHz dotclocks (and changed mclk)).

   But Matrox says on product sheet that VCO limit is 50-250 MHz, so I believe

   them (maybe that chip overheats, but it has a very big cooler (G100 has

   none), so it should work).

 + special mixed video/graphics videomodes of Mystique and Gx00 - 2G8V16 and

   G16V16 are not supported

 + color keying is not supported

 + feature connector of Mystique and Gx00 is set to VGA mode (it is disabled

   by BIOS)

 + DDC (monitor detection) is supported through dualhead driver

 + some check for input values are not so strict how it should be (you can

   specify vslen=4000 and so on).

 + maybe more...

And following features:

 + 4bpp is available only on Millennium I and Millennium II. It is hardware

   limitation.

 + selection between 1:5:5:5 and 5:6:5 16bpp videomode is done by -rgba

   option of fbset: "fbset -depth 16 -rgba 5,5,5" selects 1:5:5:5, anything

   else selects 5:6:5 mode.

 + text mode uses 6 bit VGA palette instead of 8 bit (one of 262144 colors

   instead of one of 16M colors). It is due to hardware limitation of

   Millennium I/II and SVGALib compatibility.

Benchmarks

==========

It is time to redraw whole screen 1000 times in 1024x768, 60Hz. It is

time for draw 6144000 characters on screen through /dev/vcsa

(for 32bpp it is about 3GB of data (exactly 3000 MB); for 8x16 font in

16 seconds, i.e. 187 MBps).

Times were obtained from one older version of driver, now they are about 3%

faster, it is kernel-space only time on P-II/350 MHz, Millennium I in 33 MHz

PCI slot, G200 in AGP 2x slot. I did not test vgacon.

NOACCEL

        8x16                 12x22

        Millennium I  G200   Millennium I  G200

8bpp    16.42         9.54   12.33         9.13

16bpp   21.00        15.70   19.11        15.02

24bpp   36.66        36.66   35.00        35.00

32bpp   35.00        30.00   33.85        28.66

ACCEL, nofastfont

        8x16                 12x22                6x11

        Millennium I  G200   Millennium I  G200   Millennium I  G200

8bpp     7.79         7.24   13.55         7.78   30.00        21.01

16bpp    9.13         7.78   16.16         7.78   30.00        21.01

24bpp   14.17        10.72   18.69        10.24   34.99        21.01

32bpp   16.15        16.16   18.73        13.09   34.99        21.01

ACCEL, fastfont

        8x16                 12x22                6x11

        Millennium I  G200   Millennium I  G200   Millennium I  G200

8bpp     8.41         6.01    6.54         4.37   16.00        10.51

16bpp    9.54         9.12    8.76         6.17   17.52        14.01

24bpp   15.00        12.36   11.67        10.00   22.01        18.32

32bpp   16.18        18.29*  12.71        12.74   24.44        21.00

TEXT

        8x16

        Millennium I  G200

TEXT     3.29         1.50

* Yes, it is slower than Millennium I.

Dualhead G400

=============

Driver supports dualhead G400 with some limitations:

 + secondary head shares videomemory with primary head. It is not problem

   if you have 32MB of videoram, but if you have only 16MB, you may have

   to think twice before choosing videomode (for example twice 1880x1440x32bpp

   is not possible).

 + due to hardware limitation, secondary head can use only 16 and 32bpp

   videomodes.

 + secondary head is not accelerated. There were bad problems with accelerated

   XFree when secondary head used to use acceleration.

 + secondary head always powerups in 640x480@60-32 videomode. You have to use

   fbset to change this mode.

 + secondary head always powerups in monitor mode. You have to use fbmatroxset

   to change it to TV mode. Also, you must select at least 525 lines for

   NTSC output and 625 lines for PAL output.

 + kernel is not fully multihead ready. So some things are impossible to do.

 + if you compiled it as module, you must insert i2c-matroxfb, matroxfb_maven

   and matroxfb_crtc2 into kernel.

Dualhead G450

=============

Driver supports dualhead G450 with some limitations:

 + secondary head shares videomemory with primary head. It is not problem

   if you have 32MB of videoram, but if you have only 16MB, you may have

   to think twice before choosing videomode.

 + due to hardware limitation, secondary head can use only 16 and 32bpp

   videomodes.

 + secondary head is not accelerated.

 + secondary head always powerups in 640x480@60-32 videomode. You have to use

   fbset to change this mode.

 + TV output is not supported

 + kernel is not fully multihead ready, so some things are impossible to do.

 + if you compiled it as module, you must insert matroxfb_g450 and matroxfb_crtc2

   into kernel.

--

Petr Vandrovec