[PATCH 1/1] ARM: thumb: Have the machine name indicate operation in thumb mode.

[dave.martin@linaro.org (Dave Martin)]

On Mon, May 16, 2011 at 10:32:16AM -0400, Nicolas Pitre wrote:
> On Mon, 16 May 2011, Dave Martin wrote:
> 
> > On Sat, May 14, 2011 at 11:02:32AM +0100, Russell King - ARM Linux wrote:
> > > On Sat, May 14, 2011 at 10:59:14AM +0100, Catalin Marinas wrote:
> > > > On 13 May 2011 20:53, Vadim Bendebury <vbendeb@google.com> wrote:
> > > > > This is a cosmetic change, adding a '_thumb' prefix to the
> > > > > 'Hardware' line in /proc/cpuinfo. Tested as follows:
> > > > >
> > > > > localhost ~ # dmesg | grep thumb
> > > > > [ ? ?0.000000] Machine: kaen_thumb
> > > > > localhost ~ # grep '^Hardware' /proc/cpuinfo
> > > > > Hardware ? ? ? ?: kaen_thumb
> > > > > localhost ~ #
> > > > 
> > > > Would this break any script parsing this file?
> > > > 
> > > > BTW, why do you need it? You could include the .config into the kernel
> > > > and read it via /proc.
> > > 
> > > Whether the kernel is built T2 or ARM doesn't change the userland API
> > > either, so there's no real need for userland to know how the kernel
> > > was built.
> > > 
> > > The only thing which is affected by it are kernel modules, but then we
> > > have an established way to sort out incompatible kernel modules already.
> > 
> > One corollary to that is that _if_ there's any reason why userland needs to 
> > know what instruction set the kernel was built with, then we're probably
> > doing something wrong somewhere...
> > 
> > In any case, shoehorning this information into the hardware platform name
> > seems a bit strange since this is really nothing to do with the hardware.
> > 
> > Vadim, can you explain why you think this information is needed?  If the
> > need is real, perhaps there's a better way to address it.
> 
> I think this can be useful to know how the kernel was compiled for bug 
> tracking purposes, just like we record the Git commit ID of the checked 
> out source tree, the gcc version, the build date, etc.  Which pretty 
> much indicates that the thumbness of the kernel should probably be 
> stored in the kernel banner not the platform name.

That seems a reasonable approach to me.

---Dave