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asph
l33t
Joined: 25 Aug 2003
Posts: 741
Location: Barcelona, Spain
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 Posted: Thu Sep 04, 2003 2:43 pm Post subject: Mini How-to use framebuffer in your console (penguin logo!) |
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| Quote: | | A framebuffer device is an abstraction for the graphic hardware. It represents the frame buffer of some video hardware, and allows application software to access the graphic hardware through a well-defined interface, so that the software doesn't need to know anything about the low-level interface stuff |
[Taken from Geert Uytterhoeven's framebuffer.txt in the linux kernel sources]
To use it you will have to know how to compile a kernel, so maybe you should get some information on how to do that before continuing with this howto, as i will assume you already have the know-how.
Let's see what do you have to compile in the kernel to be able to use the fb device:
| Code: | Code maturity level options --->
[*] Prompt for development and/or incomplete code/drivers
Processor type and features --->
[*] MTRR (Memory Type Range Register) support
Console Drivers ->
[*] VGA text console
[*] Video mode selection support
Frame-buffer support ->
[*] Support for frame buffer devices
[*] VESA VGA graphics console
[*] Advanced low level driver options
<*> 8 bpp packed pixels support
<*> 16 bpp packed pixels support
<*> 24 bpp packed pixels support
<*> 32 bpp packed pixels support
<*> VGA characters/attributes support
[*] Select compiled-in fonts
[*] VGA 8x8 font
[*] VGA 8x16 font |
I would recommend this settings, they are the most compatible i can think of. In the "Frame-buffer support, don't select any other card but VESA. If you don't have a vesa compatible card, get more info here.
Ok, now you have to recompile your kernel, and install it in the system.
LILO USERS:
Just add this parameter below the kernel image:
| Code: | image=/boot/bzImage
label = Linux
vga=791 |
Save the changes, run lilo and reboot 
GRUB USERS:
Just add this parameter after the passing the root path:
| Code: |
kernel /boot/vmlinuz root=/dev/hda5 read-only vga=791 |
I used 791 in the examples, it's a code for 1024x768, here you have some of the modes you can use:
| Quote: |
# Normal VGA console
# vga = normal
# VESA framebuffer console @ 1024x768x64k
# vga=791
# VESA framebuffer console @ 1024x768x32k
# vga=790
# VESA framebuffer console @ 1024x768x256
# vga=773
# VESA framebuffer console @ 800x600x64k
# vga=788
# VESA framebuffer console @ 800x600x32k
# vga=787
# VESA framebuffer console @ 800x600x256
# vga=771
# VESA framebuffer console @ 640x480x64k
# vga=785
# VESA framebuffer console @ 640x480x32k
# vga=784
# VESA framebuffer console @ 640x480x256
# vga=769 |
There is a tool named "fbset" which will allow you to change the resolution on the fly. Just 'emerge fbset':
You can change the resolution by typing:
| Code: | | fbset -fb /dev/fb0 1024x768-60 |
You have a list of the modes you can use at: /etc/fb.modes
Well, with this you should be seing the small penguin in your screen 
I plan to make this howto bigger, explaining how to use it with more cards, on X, multi-headed and so other things you can do. Anyway, I tought this could be useful for new linux users how want to get a bigger resolution in the consoles.
_________________
gentoo sex is updatedb; locate; talk; date; cd; strip; look; touch; finger; unzip; uptime; gawk; head; emerge --oneshot condom; mount; fsck; gasp; more; yes; yes; yes; more; umount; emerge -C condom; make clean; sleep |
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blue.sca
l33t
Joined: 28 Aug 2003
Posts: 680
Location: Mainz, Germany
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| Posted: Thu Sep 04, 2003 4:15 pm Post subject: |
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nice how-to, doing this later.
one question: is framebuffer able to use 1600x1200? and what are the requirements on cpu and gfx? (k 2 questions, dont bother me ) |
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asph
l33t
Joined: 25 Aug 2003
Posts: 741
Location: Barcelona, Spain
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| Posted: Fri Sep 05, 2003 7:53 am Post subject: |
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You can check the /etc/fb.modes to see if there's a 1600x1200 mode.
For 1600x1200, you try using vga=0x31F (24 bits)
Or configure fb.modes the resolution you would like to use:
mode "1600x1200 60Hz 16bit"
# D: 156.00 MHz, H: 76.200 kHz, V: 60.00 Hz
geometry 1600 1200 1600 1200 16
timings 6411 256 32 52 10 160 8
endmode
The VESA 2.0 only coberts up to 1600x1200, it will just go slow if your card sux, or you will not see the fill screen (virtual > physical). Just play with them till you find a good resolution. I find 1024x768 is a good choice, you will have to get a magnifying glass to read something
_________________
gentoo sex is updatedb; locate; talk; date; cd; strip; look; touch; finger; unzip; uptime; gawk; head; emerge --oneshot condom; mount; fsck; gasp; more; yes; yes; yes; more; umount; emerge -C condom; make clean; sleep |
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Narada
Guru
Joined: 12 Dec 2002
Posts: 300
Location: London, UK
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asph
l33t
Joined: 25 Aug 2003
Posts: 741
Location: Barcelona, Spain
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| Posted: Fri Sep 05, 2003 1:53 pm Post subject: |
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wow, great work there.. now i realise my little "howto" is too little
thanks for the link
_________________
gentoo sex is updatedb; locate; talk; date; cd; strip; look; touch; finger; unzip; uptime; gawk; head; emerge --oneshot condom; mount; fsck; gasp; more; yes; yes; yes; more; umount; emerge -C condom; make clean; sleep |
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raven.sorrow
n00b
Joined: 10 Oct 2005
Posts: 20
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| Posted: Tue Oct 11, 2005 3:16 am Post subject: |
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| I did follow this howto as closely as I could given my system. I can't get my screen to change it's resolution. FrameBuffer Support is compilied into the kernel already and I have the fbset utility. My /etc/db.modes is empty though? How would I fill it will the available modes of my monitor? A MAG 720v2? According to MAG's Website all they have a 702v2? |
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