vga 16 framebuffer

[AnonNomis]

Hello, I've been trying to get a vga frame buffer to work instead of the vesa framebuffer because intel says it doesn't work with the 815 chipset in my sony laptop.

http://support.intel.com/support/graphics/intel815/30483.htm#POS13

I compiled it in and it starts up with the boot logo but i can't get it to change resolutions. I want to up the res so that it matches the native res of my screen. Does anyone know how to change resolutions in the vga 16 framebuffer? I can't find any tables with values to pass into grub. I know with the vesa framebuffer you can pass in values like vga=791. Does the vga framebuffer have a similar option?

[keratos68]

Try enabling "mode switching" in the kernel.
_________________
Someone told me that "..they only ever made one mistake...."

...and that's when they said they were wrong!!

[AnonNomis]

Yes, i have that enabled but I can't find anything that it will accept in the vga line. vga=??? Thanks

-Simon

[keratos68]

Mmm, just check; reconfigure the kernel:

Select 'y' to CONFIG_EXPERIMENTAL

At the bottom of the config process, select

CONFIG_VGA_CONSOLE=y
CONFIG_VIDEO_SELECT=y
CONFIG_FB=y
CONFIG_DUMMY_CONSOLE=y
CONFIG_FB_VESA=y
CONFIG_FBCON_CFB8=y
CONFIG_FBCON_CFB16=y (The video card supports 16 bit colour @ 1024x768 res)
CONFIG_FBCON_CFB24=y (If you're feeling lucky)
CONFIG_FBCON_CFB32=y (This shouldn't work)
CONFIG_FONT_8x8=y
CONFIG_FONT_8x16=y

Save .config then COPY IT TO /usr/tmp/.config

Rebuild using:

make mrproper
cp /usr/tmp/.config .
make dep
make bzImage
make modules
make modules_install

Copy the new kernel to the correct place.

edit /etc/lilo.conf: In the proper image section, add the following line verbatim:

vga=0x303

You can get a larger console using vga=0x305 etc.

save/quit and run /sbin/lilo

Reboot. If it worked, you'll see a penguin and some diagnostic information in the 'vesafb' section (use dmesg to check).
_________________
Someone told me that "..they only ever made one mistake...."

...and that's when they said they were wrong!!

[AnonNomis]

I would love to try what you said but I'm not trying to use vesafb I'm
trying to use the vga16 framebuffer. Here is what my current .config
file has. I do get the tux logo on boot up with the vga16 framebuffer
but i can't change resolutions by passing in vga=0x303 or vga=0x305.
Both of these options result in a unknown video option being passed in
and I get a screen asking me to choose a font.

CONFIG_VGA_CONSOLE=y
CONFIG_VIDEO_SELECT=y
CONFIG_FB=y
CONFIG_DUMMY_CONSOLE=y
CONFIG_FB_VGA16=y (I'm using this because vesafb doesn't work on a intel 815 chipset)
CONFIG_VIDEO_SELECT=y
CONFIG_FBCON_VGA_PLANES=y
CONFIG_FBCON_ADVANCED=y
CONFIG_FBCON_CFB2=y
CONFIG_FBCON_CFB4=y (I believe this is what i'll be using for 16 colors)
CONFIG_FBCON_CFB8=y
CONFIG_FBCON_CFB16=y
CONFIG_FBCON_CFB24=y
CONFIG_FBCON_CFB32=y
CONFIG_FBCON_FONTS=y
CONFIG_FONT_8x8=y
CONFIG_FONT_8x16=y

Actually I'm beginning to question if this is even possible because of this table:

Colours 640x400 640x480 800x600 1024x768 1280x1024 1600x1200
--------+-----------------------------------------------------
4 bits | ? ? 0x302 ? ? ?
8 bits | 0x300 0x301 0x303 0x305 0x307 0x31C
15 bits | ? 0x310 0x313 0x316 0x319 0x31D
16 bits | ? 0x311 0x314 0x317 0x31A 0x31E
24 bits | ? 0x312 0x315 0x318 0x31B 0x31F
32 bits | ? ? ? ? ? ?

Its seems that 16 color at 1024x768 doesn't have a hex number, just a questionmark. Maybe it doesn't exist? I'm still not sure though since this table is for vesafb and not vga16 framebuffer.

Thanks again,
Simon

[AnonNomis]

Then again my current resolution is 640x480 at 4 bit color which isn't on the table either.

[keratos68]

Mmm, ok - vga16 eh? What happens if you use the "vga=ask" argument? At boot time, you have the option to scan, the scan will return all the modes available, and I think that's your lot!!
_________________
Someone told me that "..they only ever made one mistake...."

...and that's when they said they were wrong!!

[AnonNomis]

Ya that comes up as a invalid option also but does list a bunch of fonts i can choose from. None of them change the resolution.

[keratos68]

Well , I'm afraid I can't help you - I've looked at the Kernel VGA framebuffer code and its quite simple - provided you've compiled the fonts and support into your kernel (not module) then I see no reason why it shouldnt work - just for this thread, Ive tried no less than four VGA cards on three types of kernel with all possible vga16 modes - NO PROBLEM!!

Sorry.
_________________
Someone told me that "..they only ever made one mistake...."

...and that's when they said they were wrong!!