Date: Mon, 1 Oct 2001 22:46:04 -0500 From: Dan Nelson <dnelson@allantgroup.com> To: Mike Silbersack <silby@silby.com> Cc: freebsd-arch@FreeBSD.ORG Subject: Re: Reading physical memory in a cross-platform way Message-ID: <20011001224604.A29573@dan.emsphone.com> In-Reply-To: <20011001222555.S7118-100000@achilles.silby.com> References: <20011001222450.A39302@dan.emsphone.com> <20011001222555.S7118-100000@achilles.silby.com>
next in thread | previous in thread | raw e-mail | index | archive | help
In the last episode (Oct 01), Mike Silbersack said:
> On Mon, 1 Oct 2001, Dan Nelson wrote:
> > It looks like 'physmem' (aka the hw.physmem sysctl) is defined the
> > same way on all the systems; are you looking for something else?
> >
> > --
> > Dan Nelson
> > dnelson@allantgroup.com
>
> physmem != hw.physmem. The sysctl is actually the output of a function,
> not a simple int or the like.
Yeah, but look at the function (i386 as an example):
static int
sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
{
int error = sysctl_handle_int(oidp, 0, ctob(physmem), req);
return (error);
}
So the physmem value is just in pages; even though the different
platforms use ctob() or <mach>_ptob(), the macros all expand to
((x) << PAGE_SHIFT).
Junior Kernel Hacker project: convert alpha and ia64 to use ctob() in
the name of consistency :)
--
Dan Nelson
dnelson@allantgroup.com
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20011001224604.A29573>