Re: Removing architectures without upstream gcc support
From: Florian Fainelli
Date: Fri Feb 23 2018 - 19:16:00 EST
On 02/22/2018 07:45 AM, Arnd Bergmann wrote:
> While building the cross-toolchains, I noticed that overall, we can build almost
> all linux target architectures with upstream binutils and gcc these days,
> however there are still some exceptions, and I'd like to find out if anyone
> has objections to removing the ones that do not have upstream support.
> This are the four architectures I found:
>
> * score (s+core, sunplus core) was a proprietary RISC architecture
> made by sunplus. It is unclear if they still ship any products based on
> this architecture, all they list is either ARM Cortex-A9 or an unspecified
> RISC core that could be any of arm, mips, nds32, arc, xtensa or
> something completely different. The two maintainers have both left the
> company many years ago and have not contributed any patches in
> at least five years. There was an upstream gcc port, which was marked
> 'obsolete' in 2013 and got removed in gcc-5.0.
> I conclude that this is dead in Linux and can be removed
>
> * unicore32 was a research project at Peking University with a SoC
> based on the Intel PXA design. No gcc source code has ever been
> published, the only toolchain available is a set of binaries that include
> a gcc-4.4 compiler. The project page at
> http://mprc.pku.edu.cn/~guanxuetao/linux/ has a TODO list that has
> not been modified since 2011. The maintainer still Acks patches
> and has last sent a pull request in 2014 and last sent a patch of
> his own in 2012 when the project appears to have stalled.
> I would suggest removing this one.
>
> * 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.
>
> * Meta was ImgTec's own architecture and they upstreamed the kernel
> port just before they acquired MIPS. Apparently Meta was abandoned
> shortly afterwards and disappeared from imgtec's website in 2014.
> The maintainer is still fixing bugs in the port, but I could not find
> any toolchain more recent than
> https://github.com/img-meta/metag-buildroot/tree/metag-core/toolchain/gcc/4.2.4
> Not sure about this one, I'd be interested in more background
> from James Hogan, who probably has an opinion and might have
> newer toolchain sources.
>
> * OpenRISC is a RISC architecture with a free license and an
> active community. It seems to have lost a bit of steam after RISC-V
> is rapidly taking over that niche, but there are chips out there and
> the design isn't going away. Listing it here for completeness only
> because there is no upstream gcc port yet, but this will hopefully
> change in the future based on
> https://lists.librecores.org/pipermail/openrisc/2018-January/000958.html
> and I had no problems locating the gcc-7.x tree for building my
> toolchains. The port is actively being maintained.
>
> There are also a couple of architectures that are more or less
> unmaintained but do have working gcc support: FR-V and M32R
> have been orphaned for a while and are not getting updated
> MN10300 is still maintained officially by David Howells but doesn't
> seem any more active than the other two, the last real updates were
> in 2013.
Add blackfin to that list, there have been no responses from the
maintainers last time I posted patches to remove DSA header files, so we
had to go these through the networking tree. Have not see a Blackfin
pull request since forever, Aaron himself seems to agree this should be
removed:
http://lkml.iu.edu/hypermail/linux/kernel/1801.1/04345.html
--
Florian