On Sat, 30 Jun 2012 21:57:00 -0400, Christoffer Dall <c.dall at virtualopensystems.com> wrote: > On Sat, Jun 30, 2012 at 7:42 PM, Peter Maydell <peter.maydell at linaro.org> wrote: > > On 1 July 2012 00:17, Christoffer Dall <c.dall at virtualopensystems.com> wrote: > >> I'm writing test code for the Thumb/ARM load-store decoding and MMIO > >> code, which led me to a couple of thoughts questions: > >> > >> First, Are all memory access instructions valid for MMIO access, > >> including load/store multiple, SIMD instructions, etc.? > > > > Yes, although some of them have interesting caveats that mean > > that nobody in their right mind would actually use them for > > accessing device registers, eg: > > > > # The architecture permits an Advanced SIMD element or structure load > > # instruction to access bytes in Device or Strongly-ordered memory that > > # are not explicitly accessed by the instruction, provided the bytes > > # accessed are in a 16-byte window, aligned to 16-bytes, that contains > > # at least one byte that is explicitly accessed by the instruction > > > > ok, I'll probably punt on SIMD instructions for now then... Agreed. It'd be nice to inject some kind of trap into the guest for this though, rather than silent fail. Cheers, Rusty.
