Date: Tue, 27 Feb 2018 19:56:54 -0800 From: Khem Raj <raj.khem@...il.com> To: musl@...ts.openwall.com, Rich Felker <dalias@...c.org> Subject: Re: clz instruction is unavailable for Thumb1 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@...eaurora.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.
Powered by blists - more mailing lists
Powered by Openwall GNU/*/Linux - Powered by OpenVZ