Mayayana said:
| The only tricky part of a laptop, is the LVDS panel connection
| to the GPU. As far as I know, it isn't a Plug and Play interface.
| The GPU or chipset (for internal GPUs), doesn't know what it is.
|
| This requires "something" to be done to the bog-standard driver
| package, to make it automatically set the LCD screen to a
| usable resolution.
I didn't know about any of this. I have almost
no experience with laptops or notebooks. Are
laptops in the same category as notebooks, or
more like PCs in terms of hardware? You're saying
that PC graphic drivers won't work on either?
GPUs (or GPU + chipset combos), have defined
interfaces such as DVI, HDMI, VGA. And those are properly
fitted to do Plug and Play. They would have a serial bus
for the EDID coming back from an external monitor.
The other kind of output a GPU can have, is a parallel
digital bus of some sort, for connection to an outboard
conversion chip. You can get DVD or HDMI "transmitter" chips
(from Silicon Image), which convert a GPU bus into a usable signal.
This method has been used on some video cards, to drive one of the
faceplate connectors.
It's also possible, to drive something like LVDS (low voltage
differential) to a panel, but in that case, there was never
an intention for LVDS interfaces to drive anything like
a multi-sync monitor (i.e. something with resolution options).
Regular desktops, don't use LVDS. It is mobile devices or an all-in-one,
where a GPU may be in relatively close proximity to an LCD panel,
where there is an opportunity for a low cost LVDS ribbon cable.
The only problem with that, as I understand it, is a lack of PNP
for that particular hardware. The OS can't tell what it is driving.
Something in there, provides "fake" information, to take the
place of the missing PNP. Things like desktop video cards,
they have a VESA BIOS stored in a flash ROM on the video card.
(I've re-flashed a card here, to change that code.)
A laptop, the most appropriate storage location for a flash ROM
of that type, would be to share space within the BIOS flash chip.
That way, there would be no need to connect a config ROM to
the chipset or a similar location.
I don't know exactly how it works, but my suspicion is, the
laptop/notebook maker video driver, is a regular video driver,
with enough files added to solve the LVDS panel problem.
If the laptop with the retrofitted HD panel had worked properly,
that would prove PNP was present. When the HD panel ended up with black
bars on right side and bottom, that tells me no PNP is available in hardware.
The laptop in that case, did not know a different panel was present.
Paul