From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave.martin@linaro.org (Dave Martin) Date: Thu, 26 May 2011 14:56:04 +0100 Subject: [PATCH 1/1] ARM: thumb: Have the machine name indicate operation in thumb mode. In-Reply-To: <20110526130104.GA5762@n2100.arm.linux.org.uk> References: <20110516121657.GA7715@arm.com> <20110516144311.GC7715@arm.com> <20110518223319.GB21384@n2100.arm.linux.org.uk> <20110518225749.GF21384@n2100.arm.linux.org.uk> <20110526130104.GA5762@n2100.arm.linux.org.uk> Message-ID: <20110526135604.GA2119@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, May 26, 2011 at 02:01:04PM +0100, Russell King - ARM Linux wrote: > On Wed, May 25, 2011 at 03:08:05PM -0700, Vadim Bendebury (??) wrote: > > On Wed, May 18, 2011 at 3:57 PM, Russell King - ARM Linux < > > linux at arm.linux.org.uk> wrote: > > > In which case I think we'll have to talk to kbuild people to get > > > mkcompile_h modified. Also maybe asking what other architectures > > > do for this kind of problem may be a good idea - especially before > > > we start abusing and hacking stuff like the hardware name. > > > > So, what would be an equivalent in other architectures to ask about - it > > seems that the ability to run in Thumb/ARM mode is fairly unique for ARM. > > What about 32-bit vs 64-bit x86 ? Thumb seems different because is is irrelevant to the kernel/user ABI (or, if it's not irrelevant, we have a bug somewhere...) Documenting what ISA the kernel was built with is therefore similar to documenting what optimisation options were used -- i.e., it's interesting and occasionally useful for humans, but not something software should normally be querying or care about in any way. > > Consulting /boot/config file is not reliable: in my own setup I can netboot > > either thumb or ARM kernel without changing the root file system contents. I > > agree though that changing the hardware name is not the best way to do this > > either. > > > > I could look into adding 'thumb' to any element of the uname output, or as a > > watered down version - just add a line to dmesg output? > > The thing that I worry about is that userspace will start using this > information inappropriately. Whether the kernel is built as T2 or ARM > is really only a matter for the kernel itself (and people debugging the > kernel), rather than random userspace programs. Agreed > > Maybe a way forward would be to produce a patch for mkcompile_h, post it > to here, kbuild people and LKML and see what response is forthcoming. > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel