From: Nick Desaulniers <ndesaulniers@google.com>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Peter Smith <Peter.Smith@arm.com>, Stefan Agner <stefan@agner.ch>,
David Howells <dhowells@redhat.com>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
Manoj Gupta <manojgupta@google.com>,
Benjamin Gaignard <benjamin.gaignard@linaro.org>,
"Joel Fernandes \(Google\)" <joel@joelfernandes.org>,
Jian Cai <caij2003@gmail.com>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Ilie Halip <ilie.halip@gmail.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>,
Ard Biesheuvel <ardb@kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>,
Sami Tolvanen <samitolvanen@google.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
"Steven Rostedt \(VMware\)" <rostedt@goodmis.org>,
Jian Cai <jiancai@google.com>,
Doug Anderson <armlinux@m.disordat.com>,
Dan Williams <dan.j.williams@intel.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Patrick Bellasi <patrick.bellasi@arm.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] ARM: do not assemble iwmmxt.S with LLVM toolchain
Date: Mon, 13 Apr 2020 12:23:38 -0700 [thread overview]
Message-ID: <CAKwvOd=-u3grX3O4CtBayJYhv=mmsxMrRTF=AMcKMbphN5Xkgg@mail.gmail.com> (raw)
In-Reply-To: <20200410123301.GX25745@shell.armlinux.org.uk>
On Fri, Apr 10, 2020 at 5:33 AM Russell King - ARM Linux admin
<linux@armlinux.org.uk> wrote:
>
> For older CPUs, it doesn't matter what the latest ARM ARM says, the
> appropriate version of the ARM ARM is the one relevant for the CPU
> architecture. This is a mistake frequently made, and it's been pointed
> out by Arm Ltd in the past (before ARMv6 even came on the scene) that
> keeping older revisions is necessary if you want to be interested in
> the older architectures.
As if it never existed *waves hands*. Interesting. Does ARM still
distribute these older reference manuals? Do you keep copies of the
older revisions?
>
> However, there's an additional complication here: DEC's license from
> Arm Ltd back in the days of StrongARM allowed them to make changes to
> the architecture - that was passed over to Intel when they bought that
> part of DEC. Consequently, these "non-Arm vendor" cores contain
> extensions that are not part of the ARM ARM. iWMMXT is one such
> example, which first appeared in the Intel PXA270 SoC (an ARMv5
> derived CPU).
>
> In fact, several of the features found in later versions of the ARM
> architecture came from DEC and Intel enhancements.
>
> If your compiler/assembler only implements what is in the latest ARM
> ARM, then it is not going to be suitable for these older CPUs and
> alternate vendor "ARM compatible" CPUs.
This is a neat piece of history, thanks for sharing.
--
Thanks,
~Nick Desaulniers
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-04-13 19:23 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-09 23:27 [PATCH] ARM: do not assemble iwmmxt.S with LLVM toolchain Jian Cai
2020-04-10 0:01 ` Nick Desaulniers
2020-04-10 0:12 ` Nathan Chancellor
2020-04-10 6:38 ` Sedat Dilek
2020-04-10 7:44 ` Nathan Chancellor
2020-04-10 9:56 ` Arnd Bergmann
2020-04-10 11:15 ` Ard Biesheuvel
2020-04-10 12:33 ` Russell King - ARM Linux admin
2020-04-10 13:09 ` Ard Biesheuvel
2020-04-13 20:45 ` Nick Desaulniers
2020-04-14 8:59 ` Ard Biesheuvel
2020-04-14 18:38 ` Nick Desaulniers
2020-04-14 20:53 ` Kees Cook
2020-04-15 10:32 ` Ard Biesheuvel
2020-04-15 12:58 ` Arnd Bergmann
2020-04-15 14:44 ` Russell King - ARM Linux admin
2020-04-19 11:08 ` Stefan Agner
2020-04-15 15:44 ` Kees Cook
2020-04-17 14:12 ` Masahiro Yamada
2020-04-13 19:23 ` Nick Desaulniers [this message]
2020-04-13 21:00 ` Russell King - ARM Linux admin
2020-11-04 20:44 ` Nick Desaulniers
2020-04-13 19:20 ` Nick Desaulniers
2020-04-13 21:15 ` Andrew Lunn
2020-04-10 16:59 ` Andrew Lunn
2020-04-10 18:34 ` Russell King - ARM Linux admin
2020-04-13 19:26 ` Nick Desaulniers
2020-04-13 21:53 ` Russell King - ARM Linux admin
2020-11-07 0:10 ` [PATCH v2] Make iwmmxt.S support Clang's integrated assembler Jian Cai
2020-11-07 8:29 ` Ard Biesheuvel
2020-11-10 1:55 ` Nick Desaulniers
2020-11-10 7:35 ` Ard Biesheuvel
2020-11-10 19:26 ` Nick Desaulniers
[not found] ` <CA+SOCLJSSR62VfWhKx9R1cxT-CHXD7RN08eJBYxUH8zzyWos9Q@mail.gmail.com>
2020-11-10 20:11 ` Nick Desaulniers
2020-11-10 20:38 ` Arnd Bergmann
2020-11-10 21:35 ` Ard Biesheuvel
2020-11-12 8:42 ` Ard Biesheuvel
2020-11-12 13:06 ` Arnd Bergmann
2020-11-12 20:07 ` [PATCH v3] " Jian Cai
2020-11-17 0:37 ` [PATCH v4] " Jian Cai
2020-11-17 1:20 ` Nick Desaulniers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAKwvOd=-u3grX3O4CtBayJYhv=mmsxMrRTF=AMcKMbphN5Xkgg@mail.gmail.com' \
--to=ndesaulniers@google.com \
--cc=Peter.Smith@arm.com \
--cc=akpm@linux-foundation.org \
--cc=ardb@kernel.org \
--cc=armlinux@m.disordat.com \
--cc=arnd@arndb.de \
--cc=benjamin.gaignard@linaro.org \
--cc=bgolaszewski@baylibre.com \
--cc=caij2003@gmail.com \
--cc=clang-built-linux@googlegroups.com \
--cc=dan.j.williams@intel.com \
--cc=dhowells@redhat.com \
--cc=ebiederm@xmission.com \
--cc=gregkh@linuxfoundation.org \
--cc=ilie.halip@gmail.com \
--cc=jiancai@google.com \
--cc=joel@joelfernandes.org \
--cc=krzk@kernel.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=manojgupta@google.com \
--cc=masahiroy@kernel.org \
--cc=mchehab+samsung@kernel.org \
--cc=mhiramat@kernel.org \
--cc=patrick.bellasi@arm.com \
--cc=rostedt@goodmis.org \
--cc=samitolvanen@google.com \
--cc=stefan@agner.ch \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).