Re: [PATCH v2 02/23] xen/arm: hypercalls

2012-08-09 Thread Dave Martin
On Thu, Aug 09, 2012 at 04:37:24PM +0100, Stefano Stabellini wrote: > On Wed, 8 Aug 2012, Dave Martin wrote: > > On Mon, Aug 06, 2012 at 03:27:05PM +0100, Stefano Stabellini wrote: > > > Use r12 to pass the hypercall number to the hypervisor. > > > > > > We need a register to pass the hypercall nu

Re: [PATCH v2 02/23] xen/arm: hypercalls

2012-08-09 Thread Stefano Stabellini
On Wed, 8 Aug 2012, Dave Martin wrote: > On Mon, Aug 06, 2012 at 03:27:05PM +0100, Stefano Stabellini wrote: > > Use r12 to pass the hypercall number to the hypervisor. > > > > We need a register to pass the hypercall number because we might not > > know it at compile time and HVC only takes an im

Re: [PATCH v2 02/23] xen/arm: hypercalls

2012-08-08 Thread Dave Martin
On Mon, Aug 06, 2012 at 03:27:05PM +0100, Stefano Stabellini wrote: > Use r12 to pass the hypercall number to the hypervisor. > > We need a register to pass the hypercall number because we might not > know it at compile time and HVC only takes an immediate argument. > > Among the available regist

[PATCH v2 02/23] xen/arm: hypercalls

2012-08-06 Thread Stefano Stabellini
Use r12 to pass the hypercall number to the hypervisor. We need a register to pass the hypercall number because we might not know it at compile time and HVC only takes an immediate argument. Among the available registers r12 seems to be the best choice because it is defined as "intra-procedure ca