Implementing unique screen resolution through the video BIOS

[raffy]

Discussion of display problems in the eee and Classmate PCs has touched on the vbios trick. Barry has provided hint on the trick, tempestuous explained it, and I tried to implement it for the eee (my post is next to tempestuous').

The questions that come to mind are:

- can this be implemented in Xorg as well? (ddcprobe is in the xwin code, which [Barry says] should be bypassed)

- a number of grep commands result to error when the 915resolution line is inserted, under "if [ "$HAVEX" = "Xvesa" ]" of xwin.

Code: Select all

915resolution 43 800 480 16 # 43 is for 16-bit, 38 is for 8-bit

Is this because of the line insertion or something else failing (like the Xvesa driver)? (However, Xvesa displays correctly at videomode "0x0114 800x480x16".

Thanks in advance, and Happy Holidays!

[BarryK]

'915resolution' works fine for the Classmate, for Xorg and Xvesa.

The problem is though, detecting the hardware. In the Classmate, if I run 'ddcprobe', it reports that 'edid' failed, meaning that the LCD monitor does not support EDID, so Puppy cannot automatically determine the native screen resolution.

For the Classmate, I have to work out some way for Puppy to determine "this is a Classmate laptop" at bootup and then know to apply the 915resolution. That's what I plan to work on next, before releasing Dingo alpha4.

For the eee laptop, does 'ddcprobe' return EDID information? You should get at least one line starting with 'timing:' or 'dtiming:' if edid is working.

If not, I will have the same problem as the Classmate, and Puppy will need some way of probing and determining either the type of LCD screen or failing that some other unique identifier that this is a eee laptop.

[raffy]

You guessed it right.

Code: Select all

sh-3.00# ddcprobe
vbe: VESA 3.0 detected.
oem: Intel(r)915GM/910ML/915MS Graphics Chip Accelerated VGA BIOS
vendor: Intel Corporation
product: Intel(r)915GM/910ML/915MS Graphics Controller Hardware Version 0.0
memory: 7872kb
mode: 1280x1024x256
mode: 1280x1024x64k
mode: 1280x1024x16m
mode: 1024x768x256
mode: 1024x768x64k
mode: 1024x768x16m
mode: 640x480x16m
mode: 800x600x64k
mode: 800x600x16m
mode: 640x480x256
mode: 800x600x256
mode: 640x480x64k
edid: 
edidfail

[BarryK]

Raffy, running the eee, open a terminal and type:
# dmesg > /tmp/dmesg-eee.txt
then post it to this forum.

See my blog post, I have uniquely identified the Classmate, will do same for the eee.

[raffy]

Here it is, attached, taken from Xandros.

The storage is visible in MUT as SILICONMOTION, 4 GB storage.

[raffy]

Getting back to screen resolution issue: yes, the trick also works in Xorg. As an example for the eee, just add this line at the beginning of /usr/X11R7/bin/xwin:

Code: Select all

915resolution 43 800 480 16 # 43 is for 16-bit, 38 is for 8-bit

Exit to prompt, then command xorgwizard - choose "Other" at the bottom of the menu, press ENTER for two more dialog boxes (accepting what you see), then in the final window, you will be able to select the 800x480x16 resolution.