Re: [Qemu-devel] [PATCH RFC] target-ppc: Correctly handle translation address when bus unit ID = 0x07F

[Andreas Färber]

Am 13.06.2011 um 15:31 schrieb Alexander Graf:

> On 13.06.2011, at 12:13, Andreas Färber wrote:
>
> > +            /* Memory forced */
> > +            ctx->raddr = ((sr & 0xF) << 28) | (eaddr & 0x0FFFFFFF);
>
> This is exactly the same as ctx->raddr = eaddr, no?

No, not that I see. The manual is explicit about this calculation:

"the processor [...] generates a memory access
with the physical address specified by the lowest-order four bits in  
the segment register
(SR[28–31]) concatenated with LA4–LA31." (6-63 / 6.10.4)

That matches figure 6-26 on the following page, and I've added a  
similar comment in v2.

I see no compelling reason why the lower nibble of the SR should  
always match the SR#, the upper nibble of eaddr.

Andreas