Re: [PATCH 11/13] powerpc: Add DTS file for the Motorola PrPMC2800 platform

Segher Boessenkool wrote:

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+            partition-names = "FW Image A\0FW Config Data\0Kernel 
Image\0Filesystem\0FW Image B";

dtc now supports the syntax:
    partition-names = "FW Image A", "FW Config Data", ...
for multi-string properties to make this sort of thing less ugly.

Nice!  Can you also concatenate different property
encodings that way?  Like,
    slot-names = <5>, "Slot A", "Slot C";
or something like that?
Segher

Hi Segher,

That doesn't make sense to me.  It would be a bugger to understand the 
value of "slot-names" since <5> is a number and the rest are strings. 
How do you know it is a number?  How do you know how big it is?

You know that since it is how that particular property is
defined: it is one integer (i.e., 32-bit big-endian),
followed by a string (zero-terminated) for each set bit
in the integer.

[snip]

Not bad at all -- it is trivial to decode _if_ you know
how it is encoded.  You cannot tell by looking at the
property data only.  What is [44 54 53 00] -- just some
bytes, or the integer 0x44545300, or the string "DTS"?
You cannot tell.

OK.  I was coming from the u-boot "fdt print" command.  We do a pretty 
good job of guessing the print format (byte/word/long/string/strings), 
but this would fail the detection circuitry and be printed as a byte 
array [00, 00, 00, 05, 44, 54, ...] (the default format) because it 
takes a-priori knowledge to print it in the original input format.  Not 
quite as pretty, but NBD.

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It seems to me that it would be much better as
  slot-names = "5", "Slot A", "Slot C";
and do an atoi() conversion if you detect it is or expect it to be 
numeric.

Hey, I know!  We could redefine OF to use XML instead!
;-)

Oooo Oooo Oooo.  No wait, we're embedded, we march to the beat of a 
different drummer.  Nevermind.  :-D

Segher

Thanks,
gvb