Re: [PATCH] ARM: makefile: pass -march=armv4 to assembler even on CPU32v3

From: Jason A. Donenfeld
Date: Tue Oct 02 2018 - 00:08:46 EST


Hi Russell,

> On 1 October 2018 at 19:56, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxx> wrote:
> We could argue that the ARMv3 assembly files are now stable, so the
> chances of ldrh/strh being introduced is low, which would make this
> change tolerable, but the commit message needs to spell out that
> we lose this protection.

Actually I don't think that argument really holds too well. We very
well could introduce some new ARMv4 assembly -- an optimized crypto
routine, for example -- and it could use ldrh/strh. That isn't the
case now, but it might be the case later. For that reason, I suspect
the proper solution is just not building new cryptography assembly
that's written for ARMv4 in mind on CPU_32v3 systems. This way there's
never a mismatch of expectations.

Jason