Re: [Qemu-devel] target-sparc has inverse cwp logic for SAVE/RESTORE?

[Mark Cave-Ayland]

On 18/05/14 17:06, Olivier Danet wrote:

> The problem may be related to the fact that the 32bits SPARCv8 and 64bits 
> SPARCv9 work in opposite directions !
>
> SparcV9 standard, page 360/399 :
> The SPARC-V9 CWP register is incremented during a SAVE instruction and 
> decremented during
> a RESTORE instruction. Although this is the opposite of PSR.CWP’s behavior in 
> SPARC-V8, the
> only software it should affect is a few trap handlers that operate in 
> privileged mode, and that must
> be rewritten for SPARC-V9 anyway. This change will have no effect on 
> nonprivileged software.

Ah I wonder if that could be it? I did try swapping the 
increment/decrement operators around in the helpers, however OpenBIOS 
crashed fairly early on so it's obviously not as simple as that. I 
suspect that because a lot of the code is shared been v8/v9 then there 
are some other assumptions that would need to be corrected for this to 
work :/


ATB,

Mark.