On 6 September 2011 13:28, David Gilbert david.gilbert@linaro.org wrote:
On 6 September 2011 13:23, Kurt Taylor kurt.taylor@linaro.org wrote:
Did you mean this? https://bugs.meego.com/show_bug.cgi?id=12448
The recipe in step #1 is probably a good candidate for a FAQ on "How do I tell what features the ARM CPU on my device has?".
Yes, and might be a good topic for the NEON optimization forum as well.
As well as features I'd like to be able to get the ID of the device; while most cases are looking as to whether the device has a feature, there are cases where you want very different optimised code for different implementations (e.g. A8 v A9).
I have an old kernel patch somewhere that allows userspace to read the ID register by emulating the relevant MRC in the illegal instruction trap handler. Perhaps this is something worth reviving. With this approach, interpreting the ID value would still be left as an exercise for the application.