Re: [Qemu-devel] [PATCH 0/3] xilinx: Speed up the build

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Sat, Jun 09, 2012 at 05:31:39PM +0200, Andreas Färber wrote:
> Am 09.06.2012 17:20, schrieb Edgar E. Iglesias:
> > On Sat, Jun 09, 2012 at 03:54:28AM +0200, Andreas Färber wrote:
> >> xilinx_ethlite.c uses tswap32(). Have you ever tested this device to work on
> >> microblazeel? I wonder if we could change the device from DEVICE_NATIVE_ENDIAN
> >> to DEVICE_BIG_ENDIAN and in place of tswap32() use a bswap32() conditional on
> >> HOST_WORDS_BIGENDIAN so that it becomes independent of the target, too?
> > 
> > I don't think that will work. the swap is needed if the endianness of the host
> > is different from the one of the target...
> 
> My thinking was: If we can force the device endianness to a known value
> then only the host endianness (not the target endianness) matters
> because the Memory API will take care of the device endianness.
> 
> The question is: Is the device LE for microblazeel or is it always BE?

It can be both LE and BE

> 
> > IIRC, the issue is that the device has a built-in RAM mapped so close to
> > the regs that they end up in the same "page". With Avis memory-api maybe it's
> > possible to expose this sub-page area as a memory?
> 
> Me and Avi fixed some bugs for subpage areas, it should work in theory
> (for TCG/qtest). Not being aware of a MicroBlaze KVM, if it's a RAM
> region then we should definitely model it as such.

If that's possible, that would get rid of the swaps

Cheers