On Thu, Aug 24, 2017 at 10:28:15PM +0200, BALATON Zoltan wrote: > On Thu, 24 Aug 2017, David Gibson wrote: > > On Wed, Aug 23, 2017 at 12:16:24PM +0200, BALATON Zoltan wrote: > > > On Wed, 23 Aug 2017, David Gibson wrote: > > > > On Sun, Aug 20, 2017 at 07:23:05PM +0200, BALATON Zoltan wrote: > > > > > These registers are present in 440 SoCs (and maybe in others too) and > > > > > U-Boot accesses them when printing register info. We don't emulate > > > > > these but add them to avoid crashing when they are read or written. > > > > > > > > > > Signed-off-by: BALATON Zoltan <bala...@eik.bme.hu> > > > > > > > > I'm ok with stub implementation, but I'm a bit uncomfortable with > > > > registering these DCRs unconditionally rather than just on the chips > > > > that actually implement them. > > > > > > Problem is that I don't know which chips have these. I can only try to > > > find > > > out from the U-Boot sources where a comment says these are common > > > registers > > > for all SoCs (in u-boot/arch/powerpc/include/asm/ppc4xx.h: > > > > > > http://git.denx.de/?p=u-boot.git;a=blob;f=arch/powerpc/include/asm/ppc4xx.h;h=45ff5dbacd9243e83bb2f6551e2dd64a7e544bf5;hb=e2351d5cf1e97408b4c52bafeaa85e0ca85c920c > > > > > > while looking for this I've just noticed that u-boot has removed ppc440 > > > support just before 2017.07-rc3 so this is the last version that still has > > > these files). So if that's true it should be OK for 405 too. > > > > Ok, just to make sure I'm understanding correctly are you saying: > > > > 1) You suspect these registers were actually on all versions of the > > device, they just weren't implemented until now. > > That's what I suspect from the comment in the file quoted above but I don't > have any other evidence. > > > or > > > > 2) The registers are definitely on only some versions of the device, > > but you're not sure which ones > > I don't know any of these devices very well and have no definitive sources > to confirm so I'm not sure but I think these should be on all the versions > (at least on all three that QEMU emulates, namely 405, 440 and > 460ex).
Ah, ok. I couldn't seem to find any relevant manuals either. Ok,
given the scanty evidence we have I'm ok with including the registers
always, as proposed.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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