Date: Fri, 9 Mar 2001 17:30:26 -0800 (PST) From: Matt Dillon <dillon@earth.backplane.com> To: "Matthew Emmerton" <matt@gsicomp.on.ca> Cc: "Jordan DeLong" <fracture@allusion.net>, <freebsd-hackers@FreeBSD.ORG> Subject: Re: Kernel area libmish stuff Message-ID: <200103100130.f2A1UQj39856@earth.backplane.com> References: <20010309175233.A6880@cx420564-b.tucson1.az.home.com> <001f01c0a8ff$d64273e0$1200a8c0@gsicomp.on.ca>
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You can't safely do FP instructions in the kernel. I do not
believe the FP context is saved/restored between processes in kernel
mode, only from user mode. The kernel saves and restores the fp state
in the few places it uses FP instructions (for memory copying).
In anycase, I think there'd be a problem here.
-Matt
:There's probably a way to include *some* of the libm functions (from
:/usr/src/lib/msun, since /usr/src/lib/libm is deprecated). However, this
:would require a considerable amount of Makefile magic, and also require that
:the msun code be present in order to do a complete build of the kernel with
:modules.
:
:I doubt that this requirement would make you many friends in -questions :)
:
:> I was thinking of just getting a sintable array and making a few simple
:> functions, so the whole of libm doesn't need to be statically linked into
:the
:> module (from my understanding, once loaded, this module wont ever get
:paged out,
:> and thus it'd be _bad_ for it to be big).
:
:This is probably the best way to go, IMO.
:
:--
:Matt Emmerton
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