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Message-ID: <21986066-f72c-83ce-d1b9-ef5767fdebef@gmail.com>
Date:   Wed, 27 Apr 2022 17:01:57 -0700
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Subject: Re: [RFC PATCH v2 2/3] of: Add support for -@ when compiling overlays
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To:     Rob Herring <robh@kernel.org>,
        Detlev Casanova <detlev.casanova@collabora.com>
Cc:     linux-kernel@vger.kernel.org, arnd@arndb.de,
        bcm-kernel-feedback-list@broadcom.com, devicetree@vger.kernel.org,
        f.fainelli@gmail.com, frowand.list@gmail.com,
        linux-arm-kernel@lists.infradead.org,
        linux-rpi-kernel@lists.infradead.org, masahiroy@kernel.org,
        michal.lkml@markovi.net, ndesaulniers@google.com,
        nsaenz@kernel.org, olof@lixom.net, rjui@broadcom.com,
        sbranden@broadcom.com, soc@kernel.org, stefan.wahren@i2se.com
References: <20220427185243.173594-1-detlev.casanova@collabora.com>
 <20220427185243.173594-3-detlev.casanova@collabora.com>
 <Ymm0l2/oGpt/SeDO@robh.at.kernel.org>
From:   Florian Fainelli <f.fainelli@gmail.com>
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On 4/27/2022 2:24 PM, Rob Herring wrote:
> On Wed, Apr 27, 2022 at 02:52:42PM -0400, Detlev Casanova wrote:
>> This commit adds an option to compile all device trees with -@ to add the
>> symbol table to the Device Tree Blobs.
> 
> Why would we want to tie this to the kernel config?
> 
> Globally enabling it has already been discussed and rejected.
> 
>> It prepares the introduction of device tree overlays that are
>> not applied on device trees at compile time (dtbo files.)
>>
>> These device tree overlays will be used by either a bootloader or a
>> linux userspace tool to extend the base device tree.
>>
>> This is used e.g. for drivers that need device tree nodes for optional
>> non plug and play devices, like an external DSI touchscreen panel that
>> embeds different i2c devices to control it.
> 
> You can already set DTC_FLAGS per directory (and target?), so enable it
> for the dtbs that have overlays.

Looks like this patch series from Aurelien should take care of that:

https://lore.kernel.org/linux-arm-kernel/20220427233607.1225419-1-
aurelien@aurel32.net/
-- 
Florian