Re: [PATCH 06/24] dtoc: Support adding a string list to a device tree

[Alper Nebi Yasak <alpernebiyasak@gmail.com>]

On 24/02/2022 01:58, Simon Glass wrote:
> On Tue, 15 Feb 2022 at 04:53, Alper Nebi Yasak <alpernebiyasak@gmail.com> wrote:
>> On 08/02/2022 21:49, Simon Glass wrote:
>>> diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
>>> index 32a7aa9829..e7197f8f12 100644
>>> --- a/tools/dtoc/fdt.py
>>> +++ b/tools/dtoc/fdt.py
>>> @@ -501,6 +501,24 @@ class Node:
>>>          val = bytes(val, 'utf-8')
>>>          return self.AddData(prop_name, val + b'\0')
>>>
>>> +    def AddStringList(self, prop_name, val):
>>> +        """Add a new string-list property to a node
>>> +
>>> +        The device tree is marked dirty so that the value will be written to
>>> +        the blob on the next sync.
>>> +
>>> +        Args:
>>> +            prop_name: Name of property to add
>>> +            val (list of str): List of strings to add
>>> +
>>> +        Returns:
>>> +            Prop added
>>> +        """
>>> +        out = b''
>>> +        for string in val:
>>> +            out += bytes(string, 'utf-8') + b'\0'
>>> +        return self.AddData(prop_name, out)
>>
>> If val is an empty list this would try to set a zero-byte data, but then
>> the Prop class considers that a boolean True.
> 
> Yes, but I believe that is correct, isn't it? I did propose a change
> to DT bool props but it has not got anywhere.

I just wasn't sure about the semantics and wanted to highlight what
might be an edge case. Looking again, I think this is binary-wise
correct, but GetString and GetStringList would return True and [True]
for these boolean props where I'd want None and [].