Endianess issues

[learlo]

Does anybody know how vendors like ATI, nVidia, Trident, Matrox or STM deal with endianess issues?

I'm writing a driver for Mac OS X and it's really a pain with the chipset I'm using.

Q8]

 

[Simon F]

Does anybody know how vendors like ATI, nVidia, Trident, Matrox or STM deal with endianess issues?

I'm writing a driver for Mac OS X and it's really a pain with the chipset I'm using.

Q8]

I've no idea what's happening in current chips but PowerVR PCX2 could shuffle the data on input and output (just a matter of wiring really) to be compatible with the Mac' formats.

 

[darkblu]

I've no idea what's happening in current chips but PowerVR PCX2 could shuffle the data on input and output (just a matter of wiring really) to be compatible with the Mac' formats.

and so did the voodoos (IIRC). and knowing that ATI and NV were never single-platform-targeted, i'd say it'd be safe to assume their chips too.

 

[learlo]

Yes but

Yes thet's true but there are big differences among different chipsets in the way they perform byte swapping.

For example ATI used to have two different PCI apertures, one with no swap (for 8 bit data) and the other programmable to half swap or full swap depending on the current framebuffer depth.
It isn't clear to me how the driver could manage (without manually swap bytes) 16bit data when in full swap mode or vice versa 32 bit data when the screen is in 16 bit depth (half swap).

Does any chipset accept video memory being organized as big endian? How?

Does AGP support multiple apertures even in AGP mode?

Thanks for any information you may provide!
Q8]