[PATCH v6 2/2] Add fdtput utility to write property values to a device tree

[Jon Loeliger]

> This simple utility allows writing of values into a device tree from the
> command line. It aimes to be the opposite of fdtget.
> 
> What is it for:
> - Updating fdt values when a binary blob already exists
>    (even though source may be available it might be easier to use this
>     utility rather than sed, etc.)
> - Writing machine-specific fdt values within a build system
> 
> To use it, specify the fdt binary file on command line followed by the node
> and property to set. Then, provide a list of values to put into that
> property. Often there will be just one, but fdtput also supports arrays and
> string lists.
> 
> fdtput does not try to guess the type of the property based on looking at
> the arguments. Instead it always assumes that an integer is provided. To
> indicate that you want to write a string, use -ts. You can also provide
> hex values with -tx.
> 
> The command line arguments are joined together into a single value. For
> strings, a nul terminator is placed between each string when it is packed
> into the property. To avoid this, pass the string as a single argument.
> 
> Usage:
> 	fdtput <options> <dt file> <<node> <property> [<value>...]
> Options:
> 	-t <type>	Type of data
> 	-v		Verbose: display each value decoded from command line
> 	-h		Print this help
> 
> <type>	s=string, i=int, u=unsigned, x=hex
> 	Optional modifier prefix:
> 		hh or b=byte, h=2 byte, l=4 byte (default)
> 
> To read from stdin and write to stdout, use - as the file. So you can do:
> 
> cat somefile.dtb | fdtput -ts - /node prop "My string value" > newfile.dtb
> 
> This commit also adds basic tests to verify the major features.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>

Applied.

Also, "make check" didn't know to build fdtput nor fdtget.  So I added
a new ${TEST_BIN} in the top level Makefile to track which executables
are tested.

Thanks,
jdl