From: Richard Henderson <rth@redhat.com>
To: Tor Krill <tor@openproducts.com>, libffi-discuss@sourceware.org
Subject: Re: libffi on Cortex M4?
Date: Mon, 14 Sep 2015 19:08:00 -0000 [thread overview]
Message-ID: <55F71AEE.50004@redhat.com> (raw)
In-Reply-To: <1442256188.3397.27.camel@openproducts.com>
On 09/14/2015 11:43 AM, Tor Krill wrote:
> Dear list,
>
> I'm trying to crosscompile libffi for a Cortex-M4 platform running
> uClinux but this fails miserably during compilation with a:
>
> ../src/arm/sysv.S: Assembler messages:
> ../src/arm/sysv.S:152: Error: selected processor does not support ARM
> opcodes
> ../src/arm/sysv.S:154: Error: attempt to use an ARM instruction on a
> Thumb-only processor -- `stmfd sp!,{r0-r3,fp,lr}'
> ../src/arm/sysv.S:156: Error: attempt to use an ARM instruction on a
> Thumb-only processor -- `mov fp,sp'
> ../src/arm/sysv.S:161: Error: attempt to use an ARM instruction on a
> Thumb-only processor -- `sub sp,fp,r2'
>
> My question is simply, is thumb2 on a cortex m4 supported by libffi?
> I.e. is it my build setup that is faulty and this should work or is this
> unsupported?
Thumb2 is supported, but I think you'll find that the M4 is thumb1, which isn't.
We normally expect to have the assembly bits for libffi compiled for arm32 and
use interworking to let the C bits be built for thumb1. In order to support a
thumb1 only core would require significant work.
r~
next prev parent reply other threads:[~2015-09-14 19:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-14 18:43 Tor Krill
2015-09-14 19:08 ` Richard Henderson [this message]
2015-09-15 11:52 ` Tor Krill
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