Sigillo's framebuffer
5 September 2005

Status

The new nvidiafb still (as of 2.6.12) doesn't work right on sigillo; I need to bugreport it to Antonin.

The rivafb works fine -- but it's not compatible with the proprietary nvidia kernel module. You can play movies (but touching the keyboard will freeze the computer solid) and watch slideshows -- great for plane rides. See recipe in /root/commands.

I finally (Sep 05) discovered how people get a penguin on boot -- you need to activate FB_VESA (Device drivers | Graphics support | Support for frame buffer devices) in the kernel; cf. Documentation/fb/vesafb.txt -- I've used Linux for nearly four years, wanting a boot penguin, knowing it was possible on Sigillo (since I get it with Knoppix) and that I likely need the vesa framebuffer, but never actually activating this part of the kernel. I built it in, along with Device drivers | Graphics | Console display | Framebuffer console -- and it works! I now have a beautiful little penguin on boot, though it gets turned off by loading the keyboard that maps the vpr key (in bootmisc.sh).

Afterwards, I get a framebuffer console, which works fine both with xorg's nv and the nvidia driver -- in the latter, glxgears run at 1300fps, which is what it was doing before. It will likely also work with xorg's fbdev driver without problems -- the reason I wasn't using that is that the rivafb and nvidiafb modules don't unload. Otoh the nv driver is likely better. Anyway, the framebuffer console is not as nice as the text console, and apparently also not quite as fast, so I won't be using it on a regular basis. I haven't tried suspending it.

Now, can I watch movies directly in this vesa framebuffer? No, that doesn't work, but fbi handles slideshows fine.

Goal

I've been curious about the framebuffer and its capabilities. Does it allow me to view graphics from the CLI? Could I run a lightweight GUI using the framebuffer -- as in directfb -- and get faster responses?

Documentation and software

• Souceforge site: http://linux-fbdev.sourceforge.net
• Mailing list: http://lists.sourceforge.net/lists/listinfo/linux-fbdev-users
  
• Kernel documentation at /usr/src/linux/Documentation/fb/
• Reprogramming the default size of the framebuffer
• Debian package fbset
• Man pages: fbset(8), fb.modes(5)

Commands

• To use the framebuffer, do this on bootup:
• rmmod nvidia
• modprobe fbcon
• modprobe rivafb
• fbset fullscreen
• mplayer -vo directfb <moviename>
• fbi /windows/WINDOWS/Web/Wallpaper/*.jpg -t 5 -autozoom -edit
• w3m can use fb for web page image display
• MPlayer keyboard shortcuts (usful in framebuffer -- mouse will freeze everything!)
• Basic keys: (complete list in the man page, also check input.conf)
• <-  or  ->       seek backward/forward 10 seconds
  
• up or down       seek backward/forward  1 minute
  
• pgup or pgdown   seek backward/forward 10 minutes
  
• < or >           step backward/forward in playlist
  
• p or SPACE       pause movie (press any key to continue)
  
• q or ESC         stop playing and quit program
  
• + or -           adjust audio delay by +/- 0.1 second
  
• o                cycle OSD mode:  none / seekbar / seekbar + timer
  
• * or /           increase or decrease PCM volume
  
• z or x           adjust subtitle delay by +/- 0.1 second
  
• r or t           adjust subtitle position up/down, also see -vf expand
  
  
• Snapshot of the frame buffer content: cp /dev/fb0 myfile
• fbset: set frame buffer resolution
• fbset -i 
  
• fbset "640x480-60"
• man fb.modes
• modeline2fb (for creating entries in /etc/fb.modes)
  

Gentoo's instructions

• Kernel
  
• Disable the rivafb module
• Enable the vesa module (and no other gfx card modules) 
• Lilo
  
• vga=ask video=vesa:ywrap,mtrr
  
• Boot menu
• A menu should come up with all the strange 640x480 modes listed
• Enter 0317 at the prompt to give you a 1024x768x16bit console resolution (even though it isn't in the menu)
  
• Also try 031A
• to give you a 1280x1024x32k using the vga=794
  
• The logo should come up at the top!
  
• Lilo
• vga=791 video=vesa:ywrap,mtrr
• vga=794 video=vesa:ywarp,mtrr (1280x1024)
• vga=0x307, 0x319, 0x31a or 0x31b (1280x1024)
• vga=0x346 (=838) (1600x1200)

• if you don't load fbcon, you'll be able to unload rivafb afterwards
• you can also run X with the nv driver (but not with the nvidia driver)
  

• append = "video=riva:1024x768-16@60"
• You may be able to up to 1280x1024x256
• RivaFB support must be compiled into the kernel for this to work
• Still didn't work for me -- I didn't try all settings of course

2004-03-20

It turns out you can run X-windows with the fbdev driver!!!! You can likely also run it in dual monitors, using xinerama -- cf instructions. Dual head graphics cards are likely not supported.

2004-11-11

I wrote to Antonino Daplas <adaplas@pol.net> that the main remaining annoyance is that you can't remove the rivafb module:

You can actually, as long as you don't enable the framebuffer console. This sequence should work:

modprobe rivafb
mplayer -vo directfb
rmmod rivafb

Of course you will only have a vga console.

He also points out that the nv driver is compatible with rivafb, so you can boot into windows after using riva.

2004-11-09

2004-11-08

"If you have sample XFree86 modelines, you can use the utility modeline2fb to convert them to entries compatible with /etc/fb.modes."
It's part of the fbset package.  Here's my modeline -- not sure it's entirely correct:

ModeLine     "1280x854" 85.26 1280 1296 1552 1792 854 854 861 892 -hsync -vsync

To create the correct modes, issue

        modeline2fb /etc/X11/XF86Config

That generated this:

mode "1280x854"
  geometry   1280 854   1280 26201   8
  timings    11728   240 16   31 0   256 7
  hsync low
  vsync low
endmode

I tried setting the -d 16 and -d 24 flag for more color depth (modeline2fb -d 24 /etc/X11/XF86Config-4), but when I used those modes I got the error message there wasn't enough video memory.  The result of the 8-bit mode:

#fbset -x

Mode "1280x854"
    # D: 85.266 MHz, H: 47.581 kHz, V: 53.342 Hz
    DotClock 85.267
    HTimings 1280 1296 1552 1792
    VTimings 854 854 861 892
    Flags    "-HSync" "-VSync"    # Warning: XFree86 doesn't support accel
EndMode

2004-11-07 update

I followed these instructions from Antonino A. Daplas <adaplas@pol.net> to modify the rivafb.c file:

1. cd /usr/src/linux && pico drivers/video/riva/fbdev.c
2. search for the function "static int __devinit rivafb_probe".
3. Somewhere near the end you should see these lines:

        fb_destroy_modedb(info->monspecs.modedb);
        info->monspecs.modedb_len = 0;
        info->monspecs.modedb = NULL;

4. Remove the line "info->monspecs.modedb_len = 0"
5. Next, search for the function "static int rivafb_check_var"
6. Look for these lines:

        if (!mode_valid && !list_empty(&info->modelist))
                return -EINVAL;

7. Change it so it becomes like this:

        if (!mode_valid && info->monspecs.modedb_len)
                return -EINVAL;

8. Recompile and reboot. The end effect is rivafb will accept all modelines coming from fbset as gospel truth.

root@sigillo:/usr/src/linux# rm drivers/video/riva/*.o
root@sigillo:/usr/src/linux# make SUBDIRS=drivers/video/riva
  LD      drivers/video/riva/built-in.o
  CC [M]  drivers/video/riva/fbdev.o
  CC [M]  drivers/video/riva/riva_hw.o
  CC [M]  drivers/video/riva/nv_driver.o
  CC [M]  drivers/video/riva/rivafb-i2c.o
  LD [M]  drivers/video/riva/rivafb.o
  Building modules, stage 2.
  MODPOST
  CC      drivers/video/riva/rivafb.mod.o
  LD [M]  drivers/video/riva/rivafb.ko
root@sigillo:/usr/src/linux# cp drivers/video/riva/rivafb.ko /lib/modules/2.6.9/kernel/drivers/video/riva/

fbset "1024x768-60"

mode "1280x854-60"
     # D: 79.815 MHz, H: 51.963 kHz, V: 60.003 Hz
     geometry 1280 854 1280 854 8
     timings 12529 128 16 8 1 112 3
     rgba 8/0,8/0,8/0,0/0
endmode

root@sigillo:~# fbset "1280x854-60"
rivafb: setting virtual Y resolution to 26214
rivafb: Detected CRTC controller 1 being used
rivafb: Detected CRTC controller 1 being used
root@sigillo:~# fbset -x

Mode "1280x854"
    # D: 79.815 MHz, H: 51.963 kHz, V: 60.003 Hz
    DotClock 79.816
    HTimings 1280 1296 1408 1536
    VTimings 854 855 858 866
    Flags    "-HSync" "-VSync"    # Warning: XFree86 doesn't support accel
EndMode

2004-11-04 update

On the 2.6.9 kernel, rivafb is working, but only in 640x480, and only when the nvidia kernel module is not loaded.
It's probably been working on 2.6 for a while, and quite possibly on 2.4 too. 

Here are the results before installing the proprietary nVidia driver.

I inserted after boot with the flatpanel=1 parameter that came up by default:

Installing module rivafb.
If the device isn't there, or isn't configured correctly, this could cause your system to pause for up to a minute.

ACPI: PCI interrupt 0000:01:00.0[A] -> GSI 11 (level, low) -> IRQ 11
rivafb: nVidia device/chipset 10DE0176
rivafb: nVidia Corporation NV17 [GeForce4 420 Go 32M]
rivafb: flatpanel support enabled
rivafb: Detected CRTC controller 1 being used
rivafb: RIVA MTRR set to ON
rivafb: could not retrieve EDID from DDC/I2C
rivafb: setting virtual Y resolution to 52428
rivafb: Detected CRTC controller 1 being used
rivafb: Detected CRTC controller 1 being used
Console: switching to colour frame buffer device 80x30
rivafb: PCI nVidia NV17 framebuffer ver 0.9.5b (32MB @ 0xEC000000)

Installation succeeded.

Please press ENTER when you are ready to continue.

I can only see it on the built-in screen -- the attached screen is black. The size is perhaps 640x480. Note the version number: 0.9.5b.

root@sigillo:~# cat /proc/fb
0 NV17

The i2c modules are loaded! They must be required for the framebuffer:

Module                  Size  Used by
rivafb                 49924  1
i2c_algo_bit            8968  1 rivafb
vgastate                9472  1 rivafb
cfbimgblt               2944  1 rivafb
i2c_core               19088  2 rivafb,i2c_algo_bit

Yay!!

Settings are in /etc/fb.modes.

fbset with no parameters shows this:

root@sigillo:~# fbset mode "640x480-60"

# D: 25.176 MHz, H: 31.469 kHz, V: 59.942 Hz geometry 640 480 640 32767 8
timings 39721 40 24 32 11 96 2
accel true
rgba 8/0,8/0,8/0,0/0
endmode

The results are excellent, but of course the screen is needlessly small.

If I try issue fbset "640x480-60" I get this:

rivafb: setting virtual Y resolution to 52428
rivafb: Detected CRTC controller 1 being used

That's the default. Other settings don't work -- that is to say, all the "640x480" settings work, and the sync rate number at the end makes no difference.

Once the modules are loaded, I cannot unload them. I then issued

rmmod -f rivafb i2c_algo_bit vgastate cfbimgblt i2c_core

and the command simply didn't execute, just hung there -- everything was still working.

Module                  Size  Used by
rivafb                 49924  0
i2c_algo_bit            8968  1 rivafb
vgastate                9472  1 rivafb
cfbimgblt               2944  1 rivafb
i2c_core               19088  2 rivafb,i2c_algo_bit
nvidia               4814900  0

However, it has no effect. Since it's not used, it removes cleanly:

# rmmod rivafb i2c_algo_bit vgastate cfbimgblt i2c_core

After removing the nvidia kernel module, rivafb loads fine. I tried to play a video:

root@sigillo:/ssa/video# mplayer -vo fbdev welcome.avi

Didn't work. Size is wrong.

vesafb

I issued modprobe vesafb:

vesafb: probe of vesafb0 failed with error -6

Still, lsmod shows it itserted:

Module                  Size  Used by
vesafb                  4896  0
cfbcopyarea             3840  1 vesafb
cfbimgblt               2944  1 vesafb
cfbfillrect             3584  1 vesafb

Removing it produces this mess:

# rmmod vesafb cfbcopyarea cfbimgblt cfbfillrect

Device 'vesafb0' does not have a release() function, it is broken and must be fixed.
Badness in device_release at drivers/base/core.c:85
[<c01c7580>] kobject_cleanup+0x98/0x9a
[<c01c7582>] kobject_release+0x0/0xa
[<c01c78ce>] kref_put+0x39/0x93
[<c01c75aa>] kobject_put+0x1e/0x22
[<c01c75aa>] kobject_put+0x1e/0x22
[<c01c7582>] kobject_release+0x0/0xa
[<e0927293>] vesafb_exit+0xf/0x1f [vesafb]
[<c012dc92>] sys_delete_module+0x153/0x183
[<c01449eb>] do_munmap+0x142/0x17f
[<c010400d>] sysenter_past_esp+0x52/0x71

2.6.5 kernel update (fall 2003?)

In the 2.6.5 kernel I have rivafb enabled and get this in dmesg:

rivafb: nVidia device/chipset 10DE0176
rivafb: On a laptop.  Assuming Digital Flat Panel
rivafb: Detected CRTC controller 1 being used
rivafb: RIVA MTRR set to ON
rivafb: PCI nVidia NV20 framebuffer ver 0.9.5b (nVidiaGeForce4-4, 32MB @ 0xEC000000)
Console: switching to colour frame buffer device 80x30

fbcon                  26692  0
font                    8192  1 fbcon
rivafb                 46276  1
vgastate                9472  1 rivafb
cfbimgblt               2944  1 rivafb