[PATCH] Start arch/powerpc/boot code reorganization
Sergei Shtylyov
sshtylyov at ru.mvista.com
Fri Sep 29 06:53:21 EST 2006
Hello.
Segher Boessenkool wrote:
>>>Yes. Except a "cell" is not what you think it is. A "cell" is the
>>>size of numbers OF deals with internally; just deal with it. Of
>>>course, there's things like "#address-cells", which really mean
>>>"#-32bit-things-per-address".
>>Okay, well, when I talked about cells I meant "#-32bit-things-per-
>>address".
>>Obviously it was silly of me to think that "#address-cells" meant
>>the # of
>>address cells...
> Some background might clear things up (or not)... A "cell" is the
> unit of data in a Forth system. When OF was young (and not yet
> called OF), all systems were 32-bit, and the 32-bit-thingies in
> the properties (which weren't yet called properties) in the device
> tree were called cells as well. When 64-bit came into the picture,
> everything fell apart. The "correct" name for the property thingies
> now is "integers as encoded with encode-int".
I looked into the OF 64-bit extensions spec, and "cell" is 64-bit there.
So, "address" should look valid. I don't know whether PPC64 boxes support
64-bit OF, or only 32-bit, however, the kernel doesn't seem to deal with
64-bit ones correctly, so I'm assuming that 32-bit OF is at least available...
Anyway, I'm still missing the point of not using "address" which is
clearly intended for such case.
WBR, Sergei
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