On Thu, Feb 22, 2018 at 11:43:10PM +0100, Arnd Bergmann wrote: > On Thu, Feb 22, 2018 at 8:17 PM, Richard Kuo <rkuo@xxxxxxxxxxxxxx> wrote: > > On Thu, Feb 22, 2018 at 04:45:06PM +0100, Arnd Bergmann wrote: > >> * Hexagon is Qualcomm's DSP architecture. It is being actively used > >> in all Snapdragon ARM SoCs, but the kernel code appears to be > >> the result of a failed research project to make a standalone Hexagon > >> SoC without an ARM core. There is some information about the > >> project at https://wiki.codeaurora.org/xwiki/bin/Hexagon/ and > >> https://unix.stackexchange.com/questions/246243/what-is-was-the-qualcomm-hexagon-comet-board > >> There is a port to gcc-4.5 on the project page, which is evidently > >> abandoned, but there is an active upstream LLVM port that is > >> apparently used to build non-Linux programs. > >> I would consider this one a candidate for removal as well, given that > >> there were never any machines outside of Qualcomm that used this, > >> and they are no longer interested themselves. > > > > It's difficult for me to speak to the decisions as I can understand > > your point of view, but maybe I can speak to some of the status. > > > > We still use the port internally for kicking the tools around and other > > research projects. As you noticed we're not doing gcc anymore; we're > > using LLVM for both kernel and userspace. Yes there have been some > > caveats but it does work within confines. > > > > Time is unfortunately just limited for me to upstream some of my kernel > > fixes and cleanups, and there are some things that just haven't shown > > up externally yet. > > > > However, as James Hogan mentioned, having it in the tree really has been > > useful because it gets included in the various upstream changes and > > fixes, which we appreciate. > > > > So hopefully this will help inform the decision a little better. > > > > If you have any other questions please let me know. > > Thanks for the clarification! Since you are the maintainer and you > still consider the port useful, I don't see how anyone else would be > in a position to demand it to be removed, so we should keep it > around until you want it gone. > > I still have a few questions: > > - Any idea how we would find out of the status ever changes? E.g. if > you decide at some point that you don't find the latest Linux useful > any more for your internal work, would you send a patch for removal? Yes, we can definitely notify everyone if this happens. > - How do I build an llvm based toolchain for Hexagon? Do I need patches > on top of the llvm-6 release branch? Where can I find the corresponding > binutils-2.30 sources? The Hexagon LLVM tools available from Qualcomm should have an ABI switch that's supposed to work for this: -target hexagon-unknown-linux Admittedly I haven't tried that one. I'm unsure about the full upstream status; I'll check on that, but I think the sketchiest component out of that bunch is currently going to be the linker. Let me do some checking on all this the next couple of days and get a better answer. Thanks, Richard Kuo -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
