[RFC] Free DVMA area : Available memory on PowerPC and Sparc64

[Olivier Danet]

I don't have the cross-compilers at hand for building the PPC and Sparc64 versions of OpenBIOS,
and test the preceding patch for DVMA, but here are instead the memory properties of an iBook
G3 and a Sun Ultra10 :

-----------------------------------------------

iBook PowerPC :

/memory
    available
    	00003000	07bfd000

/cpus/PowerPC,750
    available
    	00003000	7fffd000
    	d0000000	20000000

-------------------------
OpenBIOS PPC :

/cpus/PowerPC,750@0
    available
                 00004000   07c54000
                 07e10000   f80f0000
                 00000000   ffffffff

/memory
    available
                 00004000   07c54000
                 07e10000   000f0000

The "available 00000000 ffffffff" line above looks odd.

It may confuse an OS willing to use these properties.

-----------------------------------------------

Sun Ultra 10 :

/virtual-memory
    available
    	fffff800 00000000  000007fc 00000000
    	00000001 00000000  000007ff 00000000
    	00000000 ffff0000  00000000 0000e000
    	00000000 00000000  00000000 f0000000
    	00000000 fff86000  00000000 00004000
    	00000000 fff76000  00000000 00004000
    	00000000 fff00000  00000000 00070000
    	00000000 f0800000  00000000 0d800000
/memory
    available

00000000 07f00000  00000000 0000e000
    	00000000 07c02000  00000000 002fc000
    	00000000 07002000  00000000 00bfe000
    	00000000 00000000  00000000 07000000

-------------------------
OpenBIOS Sparc64 :

/memory
    available
                 00000000 00000000   00000000 07e80000

/virtual-memory
    available
                 00000000 00000000   00000000 ffc80000
                 00000000 fff00000   ffffffff 000fffff

Here, the "ffffffff 000ffffff" looks like an off-by-one error.

-----------------------------------------------

(photos : http://temlib.org/pub/mem_ibook.jpg, http://temlib.org/pub/mem_ultra.jpg)

[RFC] Free DVMA area : Available memory on PowerPC and Sparc64

[Mark Cave-Ayland]

On 07/05/15 22:45, Olivier Danet wrote:
> I don't have the cross-compilers at hand for building the PPC and Sparc64 versions of OpenBIOS,
> and test the preceding patch for DVMA, but here are instead the memory properties of an iBook
> G3 and a Sun Ultra10 :
>
> iBook PowerPC :
>
> /memory
>    available
>    	00003000	07bfd000
>
> /cpus/PowerPC,750
>    available
>    	00003000	7fffd000
>    	d0000000	20000000
>
> OpenBIOS PPC :
>
> /cpus/PowerPC,750@0
>    available
>                  00004000   07c54000
>                  07e10000   f80f0000
>                  00000000   ffffffff
>
> /memory
>    available
>                  00004000   07c54000
>                  07e10000   000f0000
>
> The "available 00000000 ffffffff" line above looks odd.
>
> It may confuse an OS willing to use these properties.
>
> Sun Ultra 10 :
>
> /virtual-memory
>    available
>    	fffff800 00000000  000007fc 00000000
>    	00000001 00000000  000007ff 00000000
>    	00000000 ffff0000  00000000 0000e000
>    	00000000 00000000  00000000 f0000000
>    	00000000 fff86000  00000000 00004000
>    	00000000 fff76000  00000000 00004000
>    	00000000 fff00000  00000000 00070000
>    	00000000 f0800000  00000000 0d800000
> /memory
>    available
> 00000000 07f00000  00000000 0000e000
> 00000000 07c02000  00000000 002fc000
> 00000000 07002000  00000000 00bfe000
> 00000000 00000000  00000000 07000000
>
> OpenBIOS Sparc64 :
>
> /memory
>    available
>                  00000000 00000000   00000000 07e80000
>
> /virtual-memory
>    available
>                  00000000 00000000   00000000 ffc80000
>                  00000000 fff00000   ffffffff 000fffff
>
> Here, the "ffffffff 000ffffff" looks like an off-by-one error.
>
> (photos : http://temlib.org/pub/mem_ibook.jpg, http://temlib.org/pub/mem_ultra.jpg)

Thanks for the references. With the patchset I just posted, the output
now looks like this:

OpenBIOS PPC:

/memory
    available                 00004000   07c54000
                              07e10000   000f0000

/cpus/PowerPC,750
    available                 00004000   07c54000
                              07e10000   f80f0000

OpenBIOS SPARC64:

/memory
    available                 00000000 00000000   00000000 07e80000

/virtual-memory
    available                 00000000 00000000   00000000 ffc80000
                              00000000 fff00000   ffffffff 00100000

Please test and make sure that this still works with a rebased version
of your SPARC32 SunOS patch.

ATB,

Mark.