[dtc] Allow multipart property values

Jon Loeliger jdl at jdl.com
Thu Feb 8 01:35:25 EST 2007


So, like, the other day David Gibson mumbled:
> At present each property definition in a dts file must give as the
> value either a string ("abc..."), a bytestring ([12abcd...]) or a cell
> list (<1 2 3 ...>).  This patch allows a property value to be given as
> several of these, comma-separated.  The final property value is just
> the components appended together.  So a property could have a list of
> cells followed by a string, or a bytestring followed by some cells.
> Cells are always aligned, so if cells are given following a string or
> bytestring which is not a multiple of 4 bytes long, zero bytes are
> inserted to align the following cells.
> 
> The primary motivation for this feature, however, is to allow defining
> a property as a list of several strings.  This is what's needed for
> defining OF 'compatible' properties, and is less ugly and fiddly than
> using embedded \0s in the strings.

David,

I'd like a bit of clarification on the issue of null-padding.
I'm not sure how it is supposed to work for OF originally,
but I'm not sure the null-padding to mod 4 will be the same
(or usable) semantics.

In OF's original definition would "ab\0de" yield something
different than a similar "ab", [0], "de" with your proposal?
I could see that we might have:

	OF   : a b \0 d e
	Yours: a b \0 \0 \0 d e

Or does the OF spec say that it will also pad to mod 4?
Or do all strings always start on mod 4 address?

Thanks,
jdl



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