http://bugs.freedesktop.org/show_bug.cgi?id=20593
--- Comment #6 from Michael Cree
The AtomBIOS data is not aligned at all. 16 and 32 bit words can appear on any byte boundary and they do.
Yeah, that is what I was expecting. Coupled with your statement following, it explains the lack of interest in these issues.
AtomBios was written for x86 architecture which is of course little endian and has no alignment issues.
x86 does have alignment issues. I am lead to believe that accesses to a misaligned datum takes extra CPU clock cycles if it requires more than one memory access. In time critical code that may be important. Admittedly that's not an issue for us.
I started wrapping all these accesses in a macro that will do the endian byte swapping for me. It also solves the alignment problem at the same time since to do the byte swapping it is convenient to read the AtomBIOS data out one byte at a time anyway.
All this work was done just for my benefit so far and I haven't even considered whether to return any of this to X.org and whether they would even want it, since most people don't have a problem with it.
Are people not wanting to run radeonhd on PPC? Isn't that big endian? Isn't Xorg 'sposed to be a multiplatform project? If so, then porting access to the AtomBIOS, at some point in the development cycle, will become an issue. I'm happy to accept that it cannot be priority at the moment, when there are other much more important issues to focus on, nevertheless I think it is good to list these issues at this stage, and get a feel for how many people are impacted by them. That will determine implementation focus at a later stage. Michael. -- Configure bugmail: http://bugs.freedesktop.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the QA contact for the bug. _______________________________________________ xorg-team mailing list xorg-team@lists.x.org http://lists.x.org/mailman/listinfo/xorg-team -- To unsubscribe, e-mail: radeonhd+unsubscribe@opensuse.org For additional commands, e-mail: radeonhd+help@opensuse.org