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

On Mon, May 16, 2011 at 7:43 AM, Dave Martin [off-list ref] wrote:

On Mon, May 16, 2011 at 10:32:16AM -0400, Nicolas Pitre wrote:

quoted

On Mon, 16 May 2011, Dave Martin wrote:

quoted

On Sat, May 14, 2011 at 11:02:32AM +0100, Russell King - ARM Linux wrote:

quoted

On Sat, May 14, 2011 at 10:59:14AM +0100, Catalin Marinas wrote:

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On 13 May 2011 20:53, Vadim Bendebury [off-list ref] wrote:

quoted

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.

guys, thank you for your comments. Indeed, this is meant to be just a
convenience to allow to quickly tell what kind of kernel a system is
running, comes handy when there are many systems around with
differently compiled kernels.

So, would it be acceptable if I move this information into the kernel
banner (namely, add it to the machine hardware name part of the output
included in 'uname -m' and 'uname -a')?

cheers,
/vb

---Dave