Date: Thu, 1 Oct 2015 10:18:25 +0100 From: Andrew Turner <andrew@fubar.geek.nz> To: Stefan Parvu <sparvu@kronometrix.org> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: compile kernel with hard float support Message-ID: <20151001101825.44341b74@bender> In-Reply-To: <560CF28F.4000908@kronometrix.org> References: <560CF28F.4000908@kronometrix.org>
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On Thu, 1 Oct 2015 11:45:03 +0300 Stefan Parvu <sparvu@kronometrix.org> wrote: > > I understood, by default, the image > FreeBSD-armv6-11.0-RPI2-286947.img.gz has soft float support. All > float-point operations are done in software not using the ARM hardware > VFP. Correct ? No, armv6 is built with softfp. This means the compiler is free to use the VFP, but when passing floating-point data between functions it needs to copy this to the general-purpose registers. Even without this the helper functions detect the presence of the VFP unit and make use of this when available. > > If I want to build FreeBSD 11 with hard float support can I do this > already ? Do we support hard float ? And how should I compile things ? > > # setenv ARCH armv6hf (is this correct ?) > # make buildkernel KERNCONF=RPI2 The kernel doesn't use any floating-point hardware, other than to enable and disable it in the VFP driver. As such it doesn't matter if you've built the kernel for hard-float or not, it will make no difference to the code generated. Andrew
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