From: "Ulrich Weigand" <uweigand@de.ibm.com>
To: yao@codesourcery.com (Yao Qi)
Cc: anton@samba.org, gdb-patches@sourceware.org
Subject: Re: [PATCH] Detect 64-bit-ness in PowerPC Book III-E
Date: Fri, 19 Dec 2014 15:49:00 -0000 [thread overview]
Message-ID: <201412191549.sBJFnfPW030448@d03av02.boulder.ibm.com> (raw)
In-Reply-To: <87ioh8qd0w.fsf@codesourcery.com> from "Yao Qi" at Dec 19, 2014 04:06:39 PM
Yao Qi wrote:
> Ulrich Weigand <uweigand@de.ibm.com> writes:
> > Anton, what would you suggest a user program to use to safely detect
> > whether a ptrace-attached child is 64-bit or not, on either Book III-S
> > or Book III-E systems?
>
> Maybe, we can first detect the Book III-S vs. Book III-E, and then
> detect 64-bit-ness. However, I go through PowerISA, but don't find a
> way to differentiate Book III-S and Book III-E.
Well, on Linux a reliable way should be to check HWCAP for the bit:
#define PPC_FEATURE_BOOKE 0x00008000
This should be true if and only if we're running on any Book E
machine.
Of course, we cannot use the *inferior* process' HWCAP to decide
this, since we need to know the inferior process' wordsize in order
to decode its auxv. We could use gdbserver's (or native GDB's)
*own* HWCAP to check for Book E, I guess, since this is an
invariant for the whole machine ...
Bye,
Ulrich
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com
next prev parent reply other threads:[~2014-12-19 15:49 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-11 11:15 Yao Qi
2014-12-11 15:31 ` Ulrich Weigand
2014-12-19 8:06 ` Yao Qi
2014-12-19 15:49 ` Ulrich Weigand [this message]
2015-01-11 8:27 ` [PATCH 0/2, V2] " Yao Qi
2015-01-11 8:27 ` [PATCH 1/2] Move some ppc macros to nat/ppc-linux.h Yao Qi
2015-01-13 16:57 ` Ulrich Weigand
2015-01-11 8:27 ` [PATCH 2/2] Detect 64-bit-ness in PowerPC Book III-E Yao Qi
2015-01-13 17:00 ` Ulrich Weigand
2015-01-14 2:54 ` Yao Qi
2015-01-14 12:47 ` Ulrich Weigand
2015-01-14 14:22 ` Yao Qi
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