Re: Add a "enable" sysfs attribute to the pci devices to allow userspace (Xorg) to enable devices without doing foul direct access

From: Jon Smirl
Date: Sat May 13 2006 - 20:56:32 EST


On 5/13/06, Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote:
There are reasons why you may have to read the image at c0000... There's
a bunch of laptops where it's in fact the only way to get to the video
BIOS as it doesn't have a ROM attached to the video chip (it's burried
in the main BIOS which thankfully copied it to c0000 when running it).
In some cases, the BISO ROM self-modifies it's c0000 and it's that
modified copy that the X (or fbdev) driver should get. Remeber that
drivers needs access to the ROM for more than just POSTing the chip...

Whenever klibc gets merged it would probably be good to add a
libemu86. Did you get one put together that you're happy with?

Between the ROM attribute, klibc and libemu86 there will then be
enough support to write a tiny POST program that POSTs secondary and
non-x86 primary cards at boot. It will still need a little support in
sysfs for PCI bus VGA routing but we're almost there.

--
Jon Smirl
jonsmirl@xxxxxxxxx
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