[U-Boot] [PATCH 1/2] fdt: Allow indicating a node is for U-Boot proper only

From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 1/2] fdt: Allow indicating a node is for U-Boot proper only
Date: Mon, 11 Feb 2019 12:58:20 +0100	[thread overview]
Message-ID: <7b9ebc03-2f5d-8ac7-cb0c-ceea5b99093b@denx.de> (raw)
In-Reply-To: <0f3d9121c5e946fb9758681a0a3ce3e3@SFHDAG6NODE3.st.com>

On 2/11/19 12:56 PM, Patrick DELAUNAY wrote:
> Hi Marek and Simon
> 
>> From: Patrick DELAUNAY
>> Sent: vendredi 8 février 2019 13:47
>>
>> Hi Marek,
>>
>>> From: Marek Vasut <marex@denx.de>
>>> Sent: jeudi 7 février 2019 18:48
>>>
>>> On 2/7/19 6:40 PM, Patrick DELAUNAY wrote:
>>>> Hi Marek,
>>>>
>>>>> From: Marek Vasut <marex@denx.de>
>>>>> Sent: mardi 5 février 2019 09:55
>>>>>
>>>>> On 2/4/19 3:40 PM, Simon Glass wrote:
>>>>>> On Mon, 4 Feb 2019 at 03:15, Patrick Delaunay
>>>>>> <patrick.delaunay@st.com>
>>>>> wrote:
>>>>>>>
>>>>>>> This add missing parts for previous commit 06f94461a9f4
>>>>>>> ("fdt: Allow indicating a node is for U-Boot proper only")
>>>>>>>
>>>>>>> At present it is not possible to specify that a node should be
>>>>>>> used before relocation (in U-Boot proper) without it also ending
>>>>>>> up in SPL and TPL device trees. Add a new "u-boot,dm-pre-proper"
>>>>>>> boolean property
>>>>> for this.
>>>>>>>
>>>>>>>
>>>>>>> Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
>>>>>>
> ...
>>>> NB: we could also remove the tags u-boot,dm-pre-reloc/u-boot,dm-spl
>>>> : we
>>> can gain place in spl dtb
>>>>        These tags are not needed as binding is mandatory in SPL
>>>> build for ALL
>>> node  present in SPL device tree
>>>>       others node are cleaned by fdtgrep (but impact in SPL code)
>>
>> Finally I will sent a patch for this proposal (today I hope) => On my board
>> stm32mp1-ev1, the SPL device tree is reduced by 790 bytes
> 
> FYI: patch sent with http://patchwork.ozlabs.org/patch/1039756/
> 
>> NB: side effect on the patch, we only need to TAG the children (all node are
>> bounded in SPL)
>>         That improve the next point.
> 
> After test, the phandle of the parent node is remove when the tag preloc or spl is not present.... 
> So the need to tag all the DT tree  is not solved.

I'm not sure I quite understand this, but if you reference the leaf node
in the tree, you should get references to all the parent nodes for free
and they cannot be removed, right ?

-- 
Best regards,
Marek Vasut