Messages in this thread |  | | | Subject | Re: [PATCH-WIP 01/13] xen/arm: use r12 to pass the hypercall number to the hypervisor | | From | Ian Campbell <> | | Date | Wed, 29 Feb 2012 09:56:02 +0000 |
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On Wed, 2012-02-29 at 09:34 +0000, Dave Martin wrote: > On Tue, Feb 28, 2012 at 12:28:29PM +0000, Stefano Stabellini wrote: > > I don't have a very strong opinion on which register we should use, but > > I would like to avoid r7 if it is already actively used by gcc. > > But there is no framepointer for Thumb-2 code (?)
Peter Maydell suggested there was: > r7 is (used by gcc as) the Thumb frame pointer; I don't know if this > makes it worth avoiding in this context.
Sounds like it might be a gcc-ism, possibly a non-default option?
Anyway, I think r12 will be fine for our purposes so the point is rather moot.
Ian.
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