From: Khem Raj <raj.khem@gmail.com>
To: musl@lists.openwall.com, Rich Felker <dalias@libc.org>
Subject: Re: clz instruction is unavailable for Thumb1
Date: Tue, 27 Feb 2018 19:56:54 -0800 [thread overview]
Message-ID: <ba6ddad6-239e-b095-7b39-137990d21bb0@gmail.com> (raw)
In-Reply-To: <20180228010110.GS1436@brightrain.aerifal.cx>
On 2/27/18 5:01 PM, Rich Felker wrote:
> On Tue, Feb 27, 2018 at 04:37:15PM -0800, Andre McCurdy wrote:
>> On Tue, Feb 27, 2018 at 4:03 PM, Zhao, Weiming <weimingz@codeaurora.org> wrote:
>>> In arch/arm/atomic_arch.h, it checks for __ARM_ARCH >= 5, which is not
>>> sufficient.
>>>
>>> for example, for armv6-m, it only support Thumb1, which doesn't include clz.
>>>
>>> Suggest to check if it's building for thumb1:
>>
>> Musl does not currently support Thumb 1.
>
> I forget what the situation with v6-m is, and whether/how it could be
> supportable. Is it really thumb1 or some thumb2 subset that fills
> deficiencies? My recollection was that thumb1 lacks atomics, barriers,
> thread-pointer loading, and maybe even syscalls, and since the
> kuser_helper addresses are arm addresses, you can't even use them to
> get the missing functionality.
v6-m doesn't have MMU IIRC, but it might be interesting as a FDPIC
platform.
prev parent reply other threads:[~2018-02-28 3:56 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-28 0:03 Zhao, Weiming
2018-02-28 0:37 ` Andre McCurdy
2018-02-28 1:01 ` Rich Felker
2018-02-28 1:26 ` Andre McCurdy
2018-02-28 2:16 ` Rich Felker
2018-02-28 3:00 ` Andre McCurdy
2018-02-28 10:43 ` Szabolcs Nagy
2018-02-28 3:56 ` Khem Raj [this message]
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=ba6ddad6-239e-b095-7b39-137990d21bb0@gmail.com \
--to=raj.khem@gmail.com \
--cc=dalias@libc.org \
--cc=musl@lists.openwall.com \
/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.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/musl/
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).